Release 0.95: Added experimental type checking system (still missing docs, however). Made warning about old "!for" syntax configurable.

git-svn-id: https://svn.code.sf.net/p/acme-crossass/code-0/trunk@34 4df02467-bbd4-4a76-a152-e7ce94205b78
2024-12-23 10:29:46 +00:00 · 2014-06-02 00:47:46 +00:00 · 2014-06-02 00:47:46 +00:00 · d152f60acd
commit d152f60acd
parent c8ff626943
43 changed files with 1516 additions and 1219 deletions
--- a/ACME_Lib/6502/std.a
+++ b/ACME_Lib/6502/std.a
@ -1,13 +1,15 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_6502_std_a !eof
 lib_6502_std_a = 1

 ; labels and macros for plain 6502 processor

+!address {
 	cpu_nmi		= $fffa
 	cpu_reset	= $fffc
 	cpu_irq		= $fffe
+}

 ; skip byte
 !macro bit8 {
--- a/ACME_Lib/65816/std.a
+++ b/ACME_Lib/65816/std.a
@ -1,10 +1,11 @@
-;ACME 0.07
+;ACME 0.95

-!ifdef Lib_65816_std_a !eof
-Lib_65816_std_a = 1
+!ifdef lib_65816_std_a !eof
+lib_65816_std_a = 1

 ; Labels and macros for Western Digital's 65c816 processor

+!address {
 	cpu_e_cop   = $fff4
 	cpu_e_abort = $fff8
 	cpu_e_nmi   = $fffa
@ -16,6 +17,7 @@ cpu_n_brk   = $fff6
 	cpu_n_abort = $fff8
 	cpu_n_nmi   = $fffa
 	cpu_n_irq   = $fffe
+}

 !macro cpu_emu {; switch to emulation mode
 	sec
@ -71,10 +73,9 @@ cpu_n_irq   = $fffe

 !macro inc24 .t {; increase 24-bit counter
 	inc .t
-	bne .j; "*" syntax not used here because size of ".t" is unknown
+	bne +
 	inc .t + 1
-	bne .j
+	bne +
 	inc .t + 2
-.j
+
 }
-
--- a/ACME_Lib/cbm/c128/kernel.a
+++ b/ACME_Lib/cbm/c128/kernel.a
@ -1,4 +1,4 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_c128_kernel_a !eof
 lib_cbm_c128_kernel_a = 1
@ -6,6 +6,7 @@ lib_cbm_c128_kernel_a = 1
 ; Taken from the web.
 ; Sorry, I can't give credit because I don't have the URL anymore.

+!address {
 	k_spin_spout	= $ff47
 	k_close_all	= $ff4a
 	k_c64mode	= $ff4d
@ -26,7 +27,10 @@ k_indsta	= $ff77
 	k_indcmp	= $ff7a
 	k_primm		= $ff7d
 	k_release_number	= $ff80
+}
 !source <cbm/kernel.a>	; $ff81-$fff5 is backward compatible to older machines
 ; $fff6/$fff7 are unused (ff ff)
+!address {
 	k_indirect128mode	= $fff8	; indirect vector, without JMP command!
+}
 ; $fffa through $ffff are cpu hardware vectors (see <6502/std.a>)
--- a/ACME_Lib/cbm/c128/mmu.a
+++ b/ACME_Lib/cbm/c128/mmu.a
@ -1,4 +1,4 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_c128_mmu_a !eof
 lib_cbm_c128_mmu_a = 1
@ -8,6 +8,7 @@ lib_cbm_c128_mmu_a = 1

 ; registers in i/o area (i/o needs to be enabled to access these):

+!address {
 	; configuration register
 	mmu_cr_d500	= $d500	; same as "mmu_cr" at $ff00. Use "mmu_cr" instead, as that is *always* available.
 	; preconfiguration registers (internal format just like mmu_cr)
@ -15,6 +16,7 @@ mmu_pcr_a	= $d501	; c128 kernel default is $3f (BANK 0)
 	mmu_pcr_b	= $d502	; c128 kernel default is $7f (BANK 1)
 	mmu_pcr_c	= $d503	; c128 kernel default is $01 (BANK 14)
 	mmu_pcr_d	= $d504	; c128 kernel default is $41 (all system roms, with ram 1)
+}
 ; contents of cr and all four pcr:
 mmu_CR_RAMBANK_MASK	= %##......	; this controls which RAM bank is used in areas where RAM is enabled
 ;mmu_CR_RAMBANK_0	= %........
@ -64,8 +66,10 @@ mmu_pcr_d	= $d504	; c128 kernel default is $41 (all system roms, with ram 1)
 ; IFROM means internal function ROM (socket U36)
 ; EFROM means external function ROM (socket in a REU, for example)

+!address {
 	; mode configuration register
 	mmu_mcr		= $d505
+}
 ; contents:
 mmu_MCR_40COLUMNS	= %#.......	; 40/80 key: 0 means pressed, 1 means released (writable! if cleared, will always read as 0!)
 mmu_MCR_C64MODE		= %.#......	; setting this bit makes the MMU disappear from the memory map :)
@ -75,8 +79,10 @@ mmu_mcr		= $d505
 mmu_MCR_UNUSED		= %.....##.	; always set
 mmu_MCR_8502MODE	= %.......#	; setting this to zero switches to Z80 cpu

+!address {
 	; ram configuration register
 	mmu_rcr		= $d506
+}
 ; contents:
 mmu_RCR_VICBANK_MASK	= %##......	; this controls which RAM bank is "seen" by VIC
 ;mmu_RCR_VICBANK_0	= %........
@ -101,11 +107,13 @@ mmu_rcr		= $d506
 mmu_RCR_SHARESIZE_8K	= %......#.
 mmu_RCR_SHARESIZE_16K	= %......##

+!address {
 	; page pointers. writes to "high" register will be latched (reading gives old value) until "low" register is written to
 	mmu_p0low	= $d507	; page 0 pointer low (a8..a15), default $00
 	mmu_p0high	= $d508	; page 0 pointer high (a16..a19), default $00 (on an unmodified c128, only bit0 is meaningful)
 	mmu_p1low	= $d509	; page 1 pointer low (a8..a15), default $01
 	mmu_p1high	= $d50a	; page 1 pointer high (a16..a19), default $00 (on an unmodified c128, only bit0 is meaningful)
+}
 mmu_PxH_UNUSED		= %####....	; always set

 mmu_PxH_RAMBLOCK_MASK	= %....##..
@ -120,15 +128,19 @@ mmu_p1high	= $d50a	; page 1 pointer high (a16..a19), default $00 (on an unmodifi
 mmu_PxH_RAMBANK_2	= %......#.	; on an unmodified c128, there is no ram bank 2 (0 will be used instead)
 mmu_PxH_RAMBANK_3	= %......##	; on an unmodified c128, there is no ram bank 3 (1 will be used instead)

+!address {
 	; version register
 	mmu_vr		= $d50b	; read-only, value is $20
+}
 mmu_VR_BANKS_MASK	= %####....	; 2 ram banks
 mmu_VR_VERSION_MASK	= %....####	; mmu version 0
+
 ; reading addresses up until $d5ff returns $ff


 ; these registers are always available (in *every* memory configuration) unless C64 mode is entered:

+!address {
 	; configuration register
 	mmu_cr		= $ff00	; always use this instead of $d500
 	; load configuration registers:
@ -143,3 +155,4 @@ mmu_lcr_d	= $ff04	; c128 kernel default is $41 (all system roms, with ram 1)
 	; corresponding configuration register values:
 	; romc_* needs "high rom area" enabled ($c000..$ffff)
 	romc_bank_to_cr_table	= $f7f0	; 3f 7f bf ff 16 56 96 d6 2a 6a aa ea 06 0a 01 00
+}
--- a/ACME_Lib/cbm/c128/vdc.a
+++ b/ACME_Lib/cbm/c128/vdc.a
@ -1,4 +1,4 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_c128_vdc_a !eof
 lib_cbm_c128_vdc_a = 1
@ -135,14 +135,17 @@ vdcattr_B	= %......#.	; blue
 vdcattr_I	= %.......#	; intensity


+!address {
 	; direct registers
-vdc_state	= $d600	; READING this location yields status flags:
+	vdc_state	= $d600	; READING this location yields status flags, see below
+	vdc_reg		= $d600	; WRITING this location selects an indirect register
+	vdc_data	= $d601	; data of selected indirect register
+}
+; status flags in vdc_state:
 vdcstate_READY		= %#.......	; RAM access is finished
 vdcstate_LIGHTPEN	= %.#......	; light pen has been activated
 vdcstate_IN_BORDER	= %..#.....	; electron beam is in upper or lower border
 vdcstate_VERSIONMASK	= %...#####	; vdc version (0, 1 or 2)
-vdc_reg		= $d600	; WRITING this location selects an indirect register
-vdc_data	= $d601	; data of selected indirect register


 ; indirect registers		(default value, see $e179 in C128 kernal)
@ -219,6 +222,7 @@ vdcr_sync_polarity	= $25	; --	only in VDC 8568
 	vdcr_HSYNC_POLARITY	= %#.......
 	vdcr_VSYNC_POLARITY	= %.#......

+!address {
 	; the c128 ROMs contain look-up tables to convert vic color values to vdc color
 	; values and vice-versa:
 	; rom4_* needs "low rom area" enabled ($4000..$7fff)
@ -227,3 +231,4 @@ vdcr_sync_polarity	= $25	; --	only in VDC 8568
 	rom4_vic_to_vdc_color_table	= $6a4c ; 00 0f 08 07 0b 04 02 0d 0a 0c 09 06 01 05 03 0e
 	rom8_vdc_to_vic_color_table	= $81f3 ; 00 0c 06 0e 05 0d 0b 03 02 0a 08 04 09 07 0f 01
 	romc_vic_to_vdc_color_table	= $ce5c ; 00 0f 08 07 0b 04 02 0d 0a 0c 09 06 01 05 03 0e
+}
--- a/ACME_Lib/cbm/c128/vic.a
+++ b/ACME_Lib/cbm/c128/vic.a
@ -1,10 +1,11 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_c128_vic_a !eof
 lib_cbm_c128_vic_a = 1

 !source <cbm/c64/vic.a>	; registers 0..2e

+!address {
 	; registers only present in the C128 variant of this chip:
 	vic_keyboard	= $d02f
 	vic_clock	= $d030
@ -15,3 +16,4 @@ vic_clock	= $d030
 	; romc_* needs "high rom area" enabled ($c000..$ffff)
 	rom4_vic_to_petscii_color_table	= $76b5 ; 90 05 1c 9f 9c 1e 1f 9e 81 95 96 97 98 99 9a 9b
 	romc_vic_to_petscii_color_table	= $ce4c ; 90 05 1c 9f 9c 1e 1f 9e 81 95 96 97 98 99 9a 9b
+}
--- a/ACME_Lib/cbm/c128/zeropage.a
+++ b/ACME_Lib/cbm/c128/zeropage.a
@ -1,4 +1,4 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_c128_zeropage_a !eof
 lib_cbm_c128_zeropage_a = 1
@ -17,6 +17,7 @@ lib_cbm_c128_zeropage_a = 1
 ;   z_bitmsk, given as   $da and $116d
 ;   z_dejavu, given as $0a02 and $1221

+!address {
 	z_d8502		= $00
 	z_d6510		= $00
 	z_r8502		= $01
@ -290,7 +291,7 @@ z_lfor		= $0135
 	z_endfd		= $0136
 	z_sysstk	= $0137
 	z_buf		= $0200
-	; the following block is omitted in the german C128 manual
+		; this block is not in the german C128 manual:
 		z_fetch		= $02a2
 		z_fetchvec	= $02aa
 		z_stash		= $02af
@ -326,7 +327,7 @@ z_iclall	= $032c
 	z_exmon		= $032e
 	z_iload		= $0330
 	z_isave		= $0332
-	; the following block is omitted in the german C128 manual
+		; this block is not in the german C128 manual:
 		z_ctlvec	= $0334
 		z_shfvec	= $0336
 		z_escvec	= $0338
@ -414,7 +415,7 @@ z_palcnt	= $0a36
 	z_speed		= $0a37
 	z_sprites	= $0a38
 	z_blanking	= $0a39
-	; the following block is omitted in the german C128 manual
+		; this block is not in the german C128 manual:
 		z_hold_off	= $0a3a
 		z_ldtbi_sa	= $0a3b
 		z_clr_ea_lo	= $0a3c
@ -521,7 +522,7 @@ z_adray1	= $117a
 	z_adray2	= $117c
 	z_sprite_data	= $117e
 	z_vic_save	= $11d6
-	; the following block is omitted in the german C128 manual
+		; this block is not in the german C128 manual:
 		z_upper_lower	= $11eb
 		z_upper_graphic	= $11ec
 	z_oldlin	= $1200
@ -603,6 +604,7 @@ z_savram	= $12b7
 	z_defmod	= $12fa
 	z_lincnt	= $12fb
 	z_sprite_number	= $12fc
-	; the following block is omitted in the german C128 manual
+		; this block is not in the german C128 manual:
 		z_irq_wrap_flag	= $12fd
 		z_rambot	= $1c00
+}
--- a/ACME_Lib/cbm/c64/cia1.a
+++ b/ACME_Lib/cbm/c64/cia1.a
@ -1,8 +1,9 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_c64_cia1_a !eof
 lib_cbm_c64_cia1_a = 1

+!address {
 	cia1_pra	= $dc00
 	cia1_prb	= $dc01
 	cia1_ddra	= $dc02
@ -19,3 +20,4 @@ cia1_sdr	= $dc0c
 	cia1_icr	= $dc0d
 	cia1_cra	= $dc0e
 	cia1_crb	= $dc0f
+}
--- a/ACME_Lib/cbm/c64/cia2.a
+++ b/ACME_Lib/cbm/c64/cia2.a
@ -1,8 +1,9 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_c64_cia2_a !eof
 lib_cbm_c64_cia2_a = 1

+!address {
 	cia2_pra	= $dd00
 	cia2_prb	= $dd01
 	cia2_ddra	= $dd02
@ -19,3 +20,4 @@ cia2_sdr	= $dd0c
 	cia2_icr	= $dd0d
 	cia2_cra	= $dd0e
 	cia2_crb	= $dd0f
+}
--- a/ACME_Lib/cbm/c64/float.a
+++ b/ACME_Lib/cbm/c64/float.a
@ -1,4 +1,4 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_c64_float_a !eof
 lib_cbm_c64_float_a = 1
@ -6,8 +6,10 @@ lib_cbm_c64_float_a = 1
 ; Here are some definitions to help you call the floating-point functions of the
 ; C64's BASIC ROM. They work on "float registers", which are actually just
 ; structures in zero page:
+!address {
 	fac1_base	= $61	; base address of floating-point accumulator 1
 	fac2_base	= $69	; base address of floating-point accumulator 2
+}
 ; There is really no need to use these addresses directly when calling the ROM
 ; functions. You'd only need the addresses when using <cbm/flpt.a>.

@ -45,6 +47,7 @@ fac2_base	= $69	; base address of floating-point accumulator 2
 	lda .adr + 1
 }

+!address {
 	; constants in five-byte "mflpt" format
 	mflpt_pi		= $aea8	; 3.1415926...
 	mflpt_minus32768	= $b1a5	; -32768
@ -111,3 +114,4 @@ fac1_cos			= $e264 ; COS()
 	fac1_sin			= $e26b	; SIN()
 	fac1_tan			= $e2b4	; TAN()
 	fac1_atn			= $e30e	; ATN()
+}
--- a/ACME_Lib/cbm/c64/georam.a
+++ b/ACME_Lib/cbm/c64/georam.a
@ -1,4 +1,4 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_c64_georam_a !eof
 lib_cbm_c64_georam_a = 1
@ -9,12 +9,13 @@ lib_cbm_c64_georam_a = 1
 ; address $de00 in i/o space. Writing to registers allows to change which
 ; memory page is visible at that location.

+!address {
 	; memory page
 	georam_page	= $de00
-
 	; control registers (write-only, these registers can not be read)
 	georam_track	= $dffe	; 0..63, i.e. the lower six bits are significant
 	georam_sector	= $dfff	; 0..31, i.e. the lower five bits are significant
+}
 ; these are the official addresses - actually the registers are accessible
 ; *everywhere* at $dfxx, but using these locations does not clash with the
 ; registers of a Commodore REU.
--- a/ACME_Lib/cbm/c64/reu.a
+++ b/ACME_Lib/cbm/c64/reu.a
@ -1,4 +1,4 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_c64_reu_a !eof
 lib_cbm_c64_reu_a = 1
@ -8,15 +8,19 @@ lib_cbm_c64_reu_a = 1
 ; (RAM Expansion Controller) capable of direct memory access (DMA).
 ; Standard base address of control registers is $df00 in i/o space.

+!address {
 	; status register
 	rec_status	= $df00	; reading will clear IRQ, END and ERROR bits
+}
 rec_STATUS_IRQ		= %#.......
 rec_STATUS_END		= %.#......
 rec_STATUS_ERROR	= %..#.....	; for verify command
 rec_STATUS_TYPE		= %...#....	; chip type (do not use to determine unit size!)
 rec_STATUS_VERSION	= %....####
+!address {
 	; command register
 	rec_command	= $df01
+}
 rec_COMMAND_EXECUTE	= %#.......
 ;reserved		= %.#......
 rec_COMMAND_RELOAD	= %..#.....
@ -29,6 +33,7 @@ rec_command	= $df01
 rec_COMMAND_MODE_VERIFY	= %......##	; compare
 rec_COMMAND_STASH	= %#.#.....	; these wait for $ff00 before
 rec_COMMAND_FETCH	= %#.#....#	;	starting and then reload values.
+!address {
 	; internal address (computer RAM)
 	rec_int_low	= $df02
 	rec_int_high	= $df03
@ -46,10 +51,13 @@ rec_amount_low	= $df07
 	rec_amount_high	= $df08
 	; when to request interrupts
 	rec_irqctrl	= $df09
+}
 rec_IRQCTRL_ENABLE	= %#.......
 rec_IRQCTRL_ON_END	= %.#......
 rec_IRQCTRL_ON_ERROR	= %..#.....	; for verify errors
+!address {
 	; address control (set to zero for normal operation)
 	rec_addrctrl	= $df0a
+}
 rec_ADDRCTRL_FIX_INT	= %#.......
 rec_ADDRCTRL_FIX_EXT	= %.#......
--- a/ACME_Lib/cbm/c64/sid.a
+++ b/ACME_Lib/cbm/c64/sid.a
@ -1,8 +1,9 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_c64_sid_a !eof
 lib_cbm_c64_sid_a = 1

+!address {
 	; write-only registers:
 	; voice 1:
 	sid_v1_freq_lo		= $d400
@ -28,6 +29,7 @@ sid_v3_width_hi		= $d411
 	sid_v3_control		= $d412	; see below for bits
 	sid_v3_attack_decay	= $d413	; hi-nibble: attack length, low-nibble: decay length
 	sid_v3_sustain_release	= $d414	; hi-nibble: sustain volumne, low-nibble: release length
+}
 ; voice control bits:
 sid_VOICECONTROL_NOISE		= %#.......
 sid_VOICECONTROL_RECTANGLE	= %.#......
@ -37,6 +39,7 @@ sid_v3_sustain_release	= $d414	; hi-nibble: sustain volumne, low-nibble: release
 sid_VOICECONTROL_RINGMODULATION	= %.....#..
 sid_VOICECONTROL_SYNC		= %......#.
 sid_VOICECONTROL_ON		= %.......#	; 0 = release, 1 = attack/sustain/decay
+!address {
 	; registers shared by all voices:
 	sid_filter_cutoff_lo	= $d415	; only bits 0/1/2!
 	sid_filter_cutoff_hi	= $d416
@ -47,6 +50,6 @@ sid_potx		= $d419
 	sid_poty		= $d41a
 	sid_v3_waveform_output	= $d41b
 	sid_v3_adsr_output	= $d41c
-
-; Do not use the shadow copies of these registers at $d500, $d600 or $d700,
+}
+; Do not use the shadow copies of these registers at $d5xx, $d6xx or $d7xx:
 ; on a C128 they do not exist!
--- a/ACME_Lib/cbm/c64/vic.a
+++ b/ACME_Lib/cbm/c64/vic.a
@ -1,4 +1,4 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_c64_vic_a !eof
 lib_cbm_c64_vic_a = 1
@ -21,6 +21,7 @@ viccolor_LGREEN	= $d
 viccolor_LBLUE	= $e
 viccolor_GRAY3	= $f

+!address {
 	; register addresses
 	vic_xs0		= $d000
 	vic_ys0		= $d001
@ -54,7 +55,6 @@ vic_smc		= $d01c	; sprites: multi color mode
 	vic_sdx		= $d01d	; sprites: double width
 	vic_ss_collided	= $d01e	; sprite-sprite collision detect
 	vic_sd_collided	= $d01f	; sprite-data collision detect
-
 	; color registers
 	vic_cborder	= $d020	; border color
 	vic_cbg		= $d021	; general background color
@ -72,7 +72,7 @@ vic_cs4		= $d02b
 	vic_cs5		= $d02c
 	vic_cs6		= $d02d
 	vic_cs7		= $d02e
-
+}
 ; See <cbm/c128/vic.a> for the C128's two additional registers at $d02f/$d030.
 ; They are accessible even in C64 mode and $d030 can garble the video output,
 ; so be careful not to write to it accidentally in a C64 program!
--- a/ACME_Lib/cbm/kernel.a
+++ b/ACME_Lib/cbm/kernel.a
@ -1,4 +1,4 @@
-;ACME 0.94.4
+;ACME 0.95

 !ifdef lib_cbm_kernel_a !eof
 lib_cbm_kernel_a = 1
@ -7,6 +7,7 @@ lib_cbm_kernel_a = 1
 ; Sorry, I can't give credit because I don't have the URL anymore.
 ; There are alternative names for some calls.

+!address {
 	k_cint		= $ff81
 	k_ioinit	= $ff84
 	k_ramtas	= $ff87
@ -46,3 +47,4 @@ k_udtim		= $ffea
 	k_scrorg	= $ffed
 	k_plot		= $fff0	; get/set cursor (to set, clear carry)
 	k_iobase	= $fff3
+}
--- a/docs/AllPOs.txt
+++ b/docs/AllPOs.txt
@ -412,9 +412,12 @@ Examples:
 Miscellaneous:	The old syntax ("!for LABEL, END { BLOCK }" where
 		START was always implied to be 1) is still fully
 		supported, but gives a warning to get people to change
-		to the new syntax. When migrating your sources, bear
-		in mind that it is no longer possible to skip the
-		block completely by specifying a loop count of zero.
+		to the new syntax. You can disable this warning using
+		the "-Wno-old-for" switch, but then you will get
+		warnings for using the *new* syntax.
+		When migrating your sources, bear in mind that it is
+		no longer possible to skip the block completely by
+		specifying a loop count of zero.
 		Also note that with the new algorithm, LABEL has a
 		different value after the block than during the last
 		loop cycle, while the old algorithm kept that last
@ -811,6 +814,37 @@ Purpose:	Assume short (8 bits) index registers. Only needed
 		pass.


+----------------------------------------------------------------------
+Section:   Type system
+----------------------------------------------------------------------
+
+Call:		!address [ { BLOCK } ]
+or:		!address LABEL = VALUE
+Purpose:	Mark a block or a statement as "explicitly defined
+		labels are holding addresses".
+Parameters:	BLOCK: A block of assembler statements
+		Everything inside the block will be parsed as usual,
+		but labels getting explicitly defined will be marked
+		as referencing memory.
+		If no block is given, only the current statement will
+		be affected, which should then be an explicit label
+		definition.
+Aliases:	"!addr"
+Examples:	!addr	k_chrout = $ffd2	; this is an address
+			CLEAR = 147		; but this is not
+		!addr {
+			; these are addresses:
+			sid_v1_control	= $d404
+			sid_v2_control	= $d40b
+			sid_v3_control	= $d412
+		}
+		; these are not:
+		sid_VOICECONTROL_NOISE		= %#.......
+		sid_VOICECONTROL_RECTANGLE	= %.#......
+		sid_VOICECONTROL_SAWTOOTH	= %..#.....
+		sid_VOICECONTROL_TRIANGLE	= %...#....
+
+
 ----------------------------------------------------------------------
 Section:   Obsolete pseudo opcodes (they will throw errors if used)
 ----------------------------------------------------------------------
--- a/docs/Changes.txt
+++ b/docs/Changes.txt
@ -12,6 +12,19 @@ platform used. There should be another help file in this archive
 outlining the platform specific changes.


+----------------------------------------------------------------------
+Section:   New in release 0.95
+----------------------------------------------------------------------
+
+Added an experimental type system to tell addresses and non-addresses
+    apart (per default disabled; must be activated using the
+    "-Wtype-mismatch" CLI switch). The new "!address" pseudo opcode is
+    used to mark label definitions as setting address values.
+Added "-Wno-old-for" switch to disable warning about old "!for"
+    syntax. However, this will in turn enable warnings about using the
+    *new* syntax.
+
+
 ----------------------------------------------------------------------
 Section:   New in release 0.94.12
 ----------------------------------------------------------------------
--- a/docs/Errors.txt
+++ b/docs/Errors.txt
@ -55,9 +55,14 @@ Bug in ACME, code follows
 C-style "==" comparison detected.
    To check for equality, use a single '=' character instead.

-Found deprecated "!for" syntax.
+Found old "!for" syntax.
    Please update your sources to use the new "!for" syntax. See
    AllPOs.txt for details.
+    You can suppress this warning using the "-Wno-old-for" switch.
+
+Found new "!for" syntax.
+    When using the "-Wno-old-for" switch to disable the warning about
+    the older syntax, the new syntax will trigger this warning.

 Implicit label definition not in leftmost column.
    An implicit label definition has blanks before the label name.
@ -128,6 +133,12 @@ Using oversized addressing mode.
    always truncate a value to 8 bits, use the '<' operator).
    More about the postfixing method can be found in "AddrModes.txt".

+Wrong type - expected address.
+Wrong type - expected integer.
+    These warnings are only given when type checking has been enabled
+    using the "-Wtype-mismatch" switch. Make sure the argument type
+    matches the instruction's addressing mode.
+

 ----------------------------------------------------------------------
 Section:   Errors during assembly
--- a/docs/Help.txt
+++ b/docs/Help.txt
@ -105,6 +105,8 @@ ACME exists on several platforms, meaning you can easily exchange your
    sources with other people (preferring other OSes).
 ACME can convert its strings to PetSCII and screen code (Okay, this is
    C64-specific).
+ACME has a rudimentary type checking system to catch errors like
+    missing '#' characters.
 Did I mention that it is fast?


--- a/docs/QuickRef.txt
+++ b/docs/QuickRef.txt
@ -21,7 +21,9 @@ Section:   Example of what an ACME source code file looks like
 		!to "tiny.o", cbm	; set output file and format
 		* = $c000		; set program counter

-		basout = $ffd2		; explicit global label def.
+	CLEAR = 147		; a global label definition
+!addr	basout = $ffd2		; another one, marked as an address
+
 		; a string output loop:
 		ldx #0
 		beq +			; enter loop
@ -46,8 +48,19 @@ Here's the same fragment again, now with some additional info:
 ; respectively.
 		* = $c000		; set program counter
 ; This can also be done using the command line option "--setpc".
-		basout = $ffd2		; explicit global label def.
-; Now "basout" is defined as a global label having the value $ffd2.
+
+	; some global label definitions
+	CLEAR = 147	; this is a simple constant
+; Now "CLEAR" is defined as a global label having the value 147.
+!addr	basout = $ffd2	; this gets marked as an address
+; Now "basout" is defined as a global "address" type label having the
+; value $ffd2.
+	; The distinction between addresses and non-addresses only
+	; matters when the type check system gets activated using
+	; the "-Wtype-mismatch" switch. Then, a line like
+	; "lda CLEAR" would trigger a type mismatch warning because
+	; of the missing '#' character.
+
 		; a string output loop:
 		ldx #0
 		beq +			; enter loop
@ -157,6 +170,9 @@ found in the file "AllPOs.txt". Here's just a short overview:
 !warn   !error   !serious
 ...for generating warnings, errors and serious errors.

+!addr
+...to mark labels as addresses, for the optional type check system.
+

 ----------------------------------------------------------------------
 Section:   Command line arguments
@ -180,13 +196,13 @@ Available options are:
    -l, --labeldump FILE   select label dump file
        This can also be given using the "!sl" pseudo opcode.

+    --setpc NUMBER         set program counter
+        This can also be given in the source code using "* = NUMBER".
+
    --cpu CPU_TYPE         set processor type
        This can be changed in the source code using the "!cpu" pseudo
        opcode. Defaults to 6502.

-    --setpc NUMBER         set program counter
-        This can also be given in the source code using "* = NUMBER".
-
    --initmem NUMBER       define 'empty' memory
        This can also be given using the "!initmem" pseudo opcode.
        Defaults to zero.
@ -200,21 +216,17 @@ Available options are:
    -vDIGIT                set verbosity level
        Sets how much additional informational output is generated.
        Higher values mean more output:
-
        acme -v0 source.a
            This is the default: No additional output is generated,
            ACME will only display warnings and errors.
-
        acme -v1 source.a
            Now the start and end addresses of the generated output
            file are displayed, along with its size (a CBM-style
            "load address" is *not* counted).
-
        acme -v2 source.a
            In addition to the "-v1" output, ACME will announce each
            pass, will show amount and offset of "!binary" loads, and
            show start and end addresses and size of each segment.
-
        acme -v3 source.a
            In addition to the "-v2" output, ACME will now announce
            each source file.
@ -226,9 +238,14 @@ Available options are:
        (using conditional assembly in your source code file).

    -W                     fine-tune amount and type of warnings
-        Currently only sub-option is supported: "-Wno-label-indent"
-        will switch off warnings about implicit label definitions not
+        -Wno-label-indent
+            Disables warnings about implicit label definitions not
            being in the leftmost column.
+        -Wno-old-for
+            Disables warnings about the old "!for" syntax and at the
+            same time enables warnings about the _new_ "!for" syntax.
+        -Wtype-mismatch
+            Enables type checking system (warns about wrong types).

    --use-stdout           fix for 'Relaunch64' IDE
        With this option, errors are written to the standard output
@ -265,6 +282,7 @@ This is a list of the operators currently known by ACME:
       14     arcsin(v)   Inverse of sin()
       14     arccos(v)   Inverse of cos()
       14     arctan(v)   Inverse of tan()
+       14     addr(v)     Mark as address
       14     int(v)      Convert to integer
       14     float(v)    Convert to float
       13        !  v     Complement of             NOT
--- a/examples/ddrv.a
+++ b/examples/ddrv.a
@ -1,4 +1,4 @@
-;ACME 0.94
+;ACME 0.95
 ;!sl "ddrv.l"
 ; Name		DuoDriver
 ; Purpose	Input driver for mouse and joystick
@ -26,6 +26,7 @@
 ; 26 Mar 2006	Release 4.03. Adjusted source to ACME 0.91 capabilities.
 ; 25 Nov 2007	Release 4.04. Adjusted source to ACME 0.94 capabilities.
 ;  7 Apr 2013	Slightly reformatted.
+;  1 Jun 2014	Adjusted to experimental type system of ACME 0.95

 ; This source code file uses conditional assembly
 ; to decide which version to produce (C64 or C128).
@ -47,12 +48,12 @@
 !if SYSTEM = 64 {
 	* = $c000
 	!to "ddrv64.prg", cbm
-	VIC_Base	= $d000
+!addr	VIC_Base	= $d000
 }
 !if SYSTEM = 128 {
 	* = $0c00
 	!to "ddrv128.prg", cbm
-	VIC_Base	= $11d6	; Location of mirror registers
+!addr	VIC_Base	= $11d6	; Location of mirror registers
 }

 ; Pointer's maximum coordinates
@ -78,11 +79,14 @@
 ; Locations to store button states, $ff = pressed, $00 = not pressed.
 ; Mouse uses both buttons, joystick only uses "LeftButton".
 ; Location to store pointer's current character coordinates.
+!addr {
 !if SYSTEM = 64 {
 	LeftButton	= $a4
 	RightButton	= $a5
 	CharX		= $b3
 	CharY		= $b4
+	tapebuf		= $0340
+	spr_ptrs	= 2040
 }
 !if SYSTEM = 128 {
 	LeftButton	= $fa
@ -96,7 +100,6 @@
 ; x low, x high, y low, y high
 	Coordinates	= $fb	; $fb..$fe

-
 ; --- System constants

 ; Interrupt vector
@ -108,7 +111,7 @@
 	cia1_prb	= $dc01
 	cia1_ddrb	= $dc03
 	mmu_cr		= $ff00	; c128 only
-
+};addr

 ; --- Label definitions

@ -168,15 +171,15 @@ Init		lda sys_iirq
 ; Copy sprites to tape buffer
 		ldx #127
 -			lda Sprites, x
-			sta $0340, x
+			sta tapebuf, x
 			dex
 			bpl -
 		lda #Sprites_Bitmask
 ; Set sprite block pointers
 		ldx #$0d
-		stx 2040 + Sprite_A
+		stx spr_ptrs + Sprite_A
 		inx
-		stx 2040 + Sprite_B
+		stx spr_ptrs + Sprite_B
 ; Activate pointer sprites
 		ora VIC_Base + 21
 		sta VIC_Base + 21
@ -419,7 +422,7 @@ StoreOF		sta Sprites_OF	; set x overflow

 ; The initialisation routine sets the argument to the address of the
 ; previous IRQ routine.
-mod16 = * + 1:	jmp $ffff	; (self-modifying)
+mod16 = * + 1:	jmp addr($ffff)	; (self-modifying)

 ; This table is for part 8.
 ;OrTable	!byte 0, 32, 64	; VDC only
--- a/examples/macedit.a
+++ b/examples/macedit.a
@ -1,4 +1,4 @@
-;ACME 0.94.4
+;ACME 0.95
 ; ist der komplette Sourcecode von MacEdit
 ; (80-Zeichen-Version)
 ; Version 0.7
@ -76,3 +76,5 @@ Spätere Änderungen am Source:
 	Converted to UTF-8
 27 Jun 2013:
 	Adjusted to change in library.
+ 1 Jun 2014:
+	Adjusted to experimental type system of ACME 0.95
--- a/examples/me/const.a
+++ b/examples/me/const.a
@ -1,10 +1,10 @@
-;ACME 0.94.4
+;ACME 0.95

 ; Konstanten:
 	FALSE	= 0	; Das Programm verläßt sich an etlichen Stellen
 	TRUE	= $ff	; darauf, daß genau diese Werte zugewiesen wurden.
 	MODIFIED8	= $ff	; Defaultwerte für
-	MODIFIED16	= $ffff	; Selbstmodifikationen
+!addr	MODIFIED16	= $ffff	; Selbstmodifikationen

 	Char_NUL		= $00
 	Char_STOP		= $03
@ -46,6 +46,7 @@
 	lf = 8	; Filenr. & Sek.-Addy

 ; Zeropage:
+!addr {
 	D8502	= $00	; Direction
 	R8502	= $01	; Register
 	vvek	= $83	; Vektor auf LineVektor
@ -91,3 +92,4 @@
 	clrchn	= $ffcc
 	basin	= $ffcf
 	basout	= $ffd2
+}
--- a/examples/me/out.a
+++ b/examples/me/out.a
@ -1,4 +1,4 @@
-;ACME 0.94.4
+;ACME 0.95

 !zone
 F_info		ldx #hWindow_InfoBox
@ -483,7 +483,7 @@ swin	!byte 0	; Auch fuer 'lwin'
 	bckgrnd	= 26	; screencolor-register
 	flnmpos	= 87	; filenameposition
 	wsstart	= $0fd0	; windowstack-start
-	tcolor	= $f2	; attribute-buffer
+!addr	tcolor	= $f2	; attribute-buffer

 ; Subs:
 !zone
@ -505,11 +505,11 @@ init		ldx repeatedtry	; first start ?
 		stx fnbank	; filename-CR
 		dex
 		stx locks	; 'CBM-shift' off
-		stx $0ac5	; 'ASC/DIN' off
+		stx addr($0ac5)	; 'ASC/DIN' off
 		stx basic	; 'Basic-IRQ' off
 		jsr crsrinit	; init crsr
 		ldx #$0b	; VIC off
-		stx $11e7
+		stx addr($11e7)
 		lda mode	; which mode ?
 		bmi +		; if 40 then
 			jsr kernel_switchmode	; switch mode
@ -567,7 +567,7 @@ init		ldx repeatedtry	; first start ?
 		sta conreg + 1	; full RAM
 		ldx #$0b	; loop for new
 -			lda keyb, x	; keyboard-tabs
-			sta $033e, x
+			sta addr($033e), x
 			dex
 			bpl -
 		jsr handleid	; old ID ?
@ -747,7 +747,7 @@ F_gosys		+bank15
 		jsr kernel_cls	; CLS
 		lda #0		; '0' for
 		sta locks	; 'CBM-Shift' on
-		sta $0ac5	; 'ASC/DIN' on
+		sta addr($0ac5)	; 'ASC/DIN' on
 		sta basic	; 'Basic-IRQ' on
 		lda nmibuf	; restore NMI
 		ldx nmibuf + 1
--- a/src/Makefile
+++ b/src/Makefile
@ -8,7 +8,7 @@ RM		= rm
 PROGS		= acme
 BINDIR		= /usr/local/bin
 USERBIN		= $(HOME)/bin
-OBJS		= acme.o alu.o basics.o cliargs.o cpu.o dynabuf.o encoding.o flow.o global.o input.o label.o macro.o mnemo.o output.o platform.o section.o tree.o
+OBJS		= acme.o alu.o basics.o cliargs.o cpu.o dynabuf.o encoding.o flow.o global.o input.o label.o macro.o mnemo.o output.o platform.o section.o tree.o typesystem.o

 all: $(PROGS)

@ -49,6 +49,8 @@ section.o: config.h dynabuf.h global.h section.h tree.h section.h section.c

 tree.o: config.h dynabuf.h global.h label.h tree.h tree.c

+typesystem.o: config.h global.h typesystem.h typesystem.c
+
 clean:
 	-$(RM) -f *.o $(PROGS) *~ core

--- a/src/Makefile.dos
+++ b/src/Makefile.dos
@ -8,7 +8,7 @@ RM		= rm
 PROGS		= acme
 #BINDIR		= /usr/local/bin
 #USERBIN	= $(HOME)/bin
-OBJS		= acme.o alu.o cliargs.o cpu.o dynabuf.o encoding.o flow.o global.o input.o label.o macro.o mnemo.o output.o platform.o section.o tree.o
+OBJS		= acme.o alu.o cliargs.o cpu.o dynabuf.o encoding.o flow.o global.o input.o label.o macro.o mnemo.o output.o platform.o section.o tree.o typesystem.o

 all: $(PROGS)

@ -50,6 +50,8 @@ section.o: config.h dynabuf.h global.h section.h tree.h section.h section.c

 tree.o: config.h dynabuf.h global.h label.h tree.h tree.c

+typesystem.o: config.h global.h typesystem.h typesystem.c
+
 clean:
 	del *.o
 #	-$(RM) -f *.o $(PROGS) *~ core
--- a/src/Makefile.mingw
+++ b/src/Makefile.mingw
@ -15,8 +15,8 @@ USERBIN		= $(HOME)/bin

 all: $(PROGS)

-acme.exe: acme.o alu.o basics.o cliargs.o cpu.o dynabuf.o encoding.o flow.o global.o input.o label.o macro.o mnemo.o output.o platform.o section.o tree.o _dos.o resource.res
-	$(CC) $(LIBS) $(CFLAGS) -o acme acme.o alu.o basics.o cliargs.o cpu.o dynabuf.o encoding.o flow.o global.o input.o label.o macro.o mnemo.o output.o platform.o section.o tree.o resource.res
+acme.exe: acme.o alu.o basics.o cliargs.o cpu.o dynabuf.o encoding.o flow.o global.o input.o label.o macro.o mnemo.o output.o platform.o section.o tree.o typesystem.o_dos.o resource.res
+	$(CC) $(LIBS) $(CFLAGS) -o acme acme.o alu.o basics.o cliargs.o cpu.o dynabuf.o encoding.o flow.o global.o input.o label.o macro.o mnemo.o output.o platform.o section.o tree.o typesystem.o resource.res
 	strip acme.exe


@ -53,6 +53,8 @@ section.o: config.h dynabuf.h global.h section.h tree.h section.h section.c

 tree.o: config.h dynabuf.h global.h label.h tree.h tree.c

+typesystem.o: config.h global.h typesystem.h typesystem.c
+
 # _dos.o: _dos.h

 win/resource.rc: acme.c
--- a/src/Makefile.riscos
+++ b/src/Makefile.riscos
@ -8,7 +8,7 @@ RM		= rm
 PROGS		= acme
 #BINDIR		= /usr/local/bin
 #USERBIN	= $(HOME)/bin
-OBJS		= acme.o alu.o basics.o cliargs.o cpu.o dynabuf.o encoding.o flow.o global.o input.o label.o macro.o mnemo.o output.o platform.o section.o tree.o
+OBJS		= acme.o alu.o basics.o cliargs.o cpu.o dynabuf.o encoding.o flow.o global.o input.o label.o macro.o mnemo.o output.o platform.o section.o tree.o typesystem.o

 all: $(PROGS)

@ -50,6 +50,8 @@ section.o: config.h dynabuf.h global.h section.h tree.h section.h section.c

 tree.o: config.h dynabuf.h global.h label.h tree.h tree.c

+typesystem.o: config.h global.h typesystem.h typesystem.c
+
 clean:
 	wipe o.* ~c
 #	-$(RM) -f *.o $(PROGS) *~ core
--- a/src/acme.c
+++ b/src/acme.c
@ -15,9 +15,9 @@
 // along with this program; if not, write to the Free Software
 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

-#define RELEASE		"0.94.12"	// update before release (FIXME)
-#define CODENAME	"Zarquon"	// update before release
-#define CHANGE_DATE	"31 May"	// update before release
+#define RELEASE		"0.95"		// update before release (FIXME)
+#define CODENAME	"Fenchurch"	// update before release
+#define CHANGE_DATE	"2 Jun"		// update before release
 #define CHANGE_YEAR	"2014"		// update before release
 //#define HOME_PAGE	"http://home.pages.de/~mac_bacon/smorbrod/acme/"	// FIXME
 #define HOME_PAGE	"http://sourceforge.net/p/acme-crossass/"	// FIXME
@ -64,6 +64,8 @@ static const char	name_dumpfile[]		= "label dump filename";
 #define OPTION_VERSION		"version"
 // options for "-W"
 #define OPTIONWNO_LABEL_INDENT	"no-label-indent"
+#define OPTIONWNO_OLD_FOR	"no-old-for"
+#define OPTIONWTYPE_MISMATCH	"type-mismatch"


 // variables
@ -126,6 +128,8 @@ static void show_help_and_exit(void)
 // as long as there is only one -W option:
 #define OPTIONWNO_LABEL_INDENT	"no-label-indent"
 "  -W" OPTIONWNO_LABEL_INDENT "      suppress warnings about indented labels\n"
+"  -W" OPTIONWNO_OLD_FOR "           suppress warnings about old \"!for\" syntax\n"
+"  -W" OPTIONWTYPE_MISMATCH "        enable type checking (warn about type mismatch)\n"
 // when there are more, use next line and add a separate function:
 //"  -W                     show warning level options\n"
 "      --" OPTION_USE_STDOUT "       fix for 'Relaunch64' IDE (see docs)\n"
@ -425,6 +429,12 @@ static char short_option(const char *argument)
 			if (strcmp(argument + 1, OPTIONWNO_LABEL_INDENT) == 0) {
 				warn_on_indented_labels = FALSE;
 				goto done;
+			} else if (strcmp(argument + 1, OPTIONWNO_OLD_FOR) == 0) {
+				warn_on_old_for = FALSE;
+				goto done;
+			} else if (strcmp(argument + 1, OPTIONWTYPE_MISMATCH) == 0) {
+				warn_on_type_mismatch = TRUE;
+				goto done;
 			} else {
 				fprintf(stderr, "%sUnknown warning level.\n", cliargs_error);
 				exit(EXIT_FAILURE);
--- a/src/alu.c
+++ b/src/alu.c
@ -48,6 +48,7 @@ enum operator_handle {
 	OPHANDLE_END,		//		"reached end of expression"
 	OPHANDLE_RETURN,	//		"return value to caller"
 //	functions
+	OPHANDLE_ADDR,		//	addr(v)
 	OPHANDLE_INT,		//	int(v)
 	OPHANDLE_FLOAT,		//	float(v)
 	OPHANDLE_SIN,		//	sin(v)
@ -129,6 +130,7 @@ static struct operator ops_negate	= {OPHANDLE_NEGATE,	28};	// monadic
 static struct operator ops_powerof	= {OPHANDLE_POWEROF,	29};	// dyadic, right-associative
 static struct operator ops_not		= {OPHANDLE_NOT,	30};	// monadic
 	// function calls act as if they were monadic operators
+static struct operator ops_addr		= {OPHANDLE_ADDR,	32};	// function
 static struct operator ops_int		= {OPHANDLE_INT,	32};	// function
 static struct operator ops_float	= {OPHANDLE_FLOAT,	32};	// function
 static struct operator ops_sin		= {OPHANDLE_SIN,	32};	// function
@ -176,6 +178,7 @@ static struct node_t	operator_list[]	= {
 };
 static struct node_t	*function_tree	= NULL;	// tree to hold functions
 static struct node_t	function_list[]	= {
+	PREDEFNODE("addr",	&ops_addr),
 	PREDEFNODE("int",	&ops_int),
 	PREDEFNODE("float",	&ops_float),
 	PREDEFNODE(s_arcsin,	&ops_arcsin),
@ -193,18 +196,22 @@ static struct node_t	function_list[]	= {
 #define RIGHT_INTVAL	(operand_stack[operand_sp-1].val.intval)
 #define LEFT_FPVAL	(operand_stack[operand_sp-2].val.fpval)
 #define RIGHT_FPVAL	(operand_stack[operand_sp-1].val.fpval)
+#define LEFT_ADDRREFS	(operand_stack[operand_sp-2].addr_refs)
+#define RIGHT_ADDRREFS	(operand_stack[operand_sp-1].addr_refs)

 #define PUSH_OPERATOR(x)	operator_stack[operator_sp++] = (x)

-#define PUSH_INTOPERAND(i, f)				\
+#define PUSH_INTOPERAND(i, f, r)			\
 do {							\
 	operand_stack[operand_sp].flags = (f);		\
-	operand_stack[operand_sp++].val.intval = (i);	\
+	operand_stack[operand_sp].val.intval = (i);	\
+	operand_stack[operand_sp++].addr_refs = (r);	\
 } while (0)
 #define PUSH_FPOPERAND(fp, f)					\
 do {								\
 	operand_stack[operand_sp].flags = (f) | MVALUE_IS_FP;	\
-	operand_stack[operand_sp++].val.fpval = (fp);		\
+	operand_stack[operand_sp].val.fpval = (fp);		\
+	operand_stack[operand_sp++].addr_refs = 0;		\
 } while (0)


@ -353,7 +360,7 @@ static void parse_quoted_character(char closing_quote)
 			Throw_error("There's more than one character.");
 			Input_skip_remainder();
 		}
-	PUSH_INTOPERAND(value, MVALUE_GIVEN | MVALUE_ISBYTE);
+	PUSH_INTOPERAND(value, MVALUE_GIVEN | MVALUE_ISBYTE, 0);
 	// Now GotByte = char following closing quote (or CHAR_EOS on error)
 }

@ -393,7 +400,7 @@ static void parse_binary_value(void)	// Now GotByte = "%" or "b"
 				flags |= MVALUE_FORCE16;
 		}
 	}
-	PUSH_INTOPERAND(value, flags);
+	PUSH_INTOPERAND(value, flags, 0);
 	// Now GotByte = non-binary char
 }

@ -437,7 +444,7 @@ static void parse_hexadecimal_value(void)	// Now GotByte = "$" or "x"
 				flags |= MVALUE_FORCE16;
 		}
 	}
-	PUSH_INTOPERAND(value, flags);
+	PUSH_INTOPERAND(value, flags, 0);
 	// Now GotByte = non-hexadecimal char
 }

@ -497,7 +504,7 @@ static void parse_decimal_value(void)	// Now GotByte = first digit
 		GetByte();
 		parse_frac_part(intval);
 	} else {
-		PUSH_INTOPERAND(intval, MVALUE_GIVEN);
+		PUSH_INTOPERAND(intval, MVALUE_GIVEN, 0);
 	}
 	// Now GotByte = non-decimal char
 }
@ -527,7 +534,7 @@ static void parse_octal_value(void)	// Now GotByte = "&"
 				flags |= MVALUE_FORCE16;
 		}
 	}
-	PUSH_INTOPERAND(value, flags);
+	PUSH_INTOPERAND(value, flags, 0);
 	// Now GotByte = non-octal char
 }

@ -535,11 +542,11 @@ static void parse_octal_value(void)	// Now GotByte = "&"
 // Parse program counter ('*')
 static void parse_program_counter(void)	// Now GotByte = "*"
 {
-	struct result_int_t	pc;
+	struct result_t	pc;

 	GetByte();
 	vcpu_read_pc(&pc);
-	PUSH_INTOPERAND(pc.intval, pc.flags | MVALUE_EXISTS);
+	PUSH_INTOPERAND(pc.val.intval, pc.flags | MVALUE_EXISTS, pc.addr_refs);
 }


@ -698,7 +705,7 @@ static void expect_operand_or_monadic_operator(void)
 			}
 		} else {
 			// illegal character read - so don't go on
-			PUSH_INTOPERAND(0, 0);
+			PUSH_INTOPERAND(0, 0, 0);	// push dummy operand so stack is ok
 			// push pseudo value, EXISTS flag is clear
 			if (operator_stack[operator_sp-1] == &ops_return) {
 				PUSH_OPERATOR(&ops_end);
@ -840,7 +847,7 @@ static void expect_dyadic_operator(void)
 		//break; unreachable
 // end of expression or text version of dyadic operator
 	default:
-		// check string version of operators
+		// check string versions of operators
 		if (BYTEFLAGS(GotByte) & STARTS_KEYWORD) {
 			Input_read_and_lower_keyword();
 			// Now GotByte = illegal char
@ -878,6 +885,7 @@ static void perform_fp(double (*fn)(double))
 		RIGHT_FLAGS |= MVALUE_IS_FP;
 	}
 	RIGHT_FPVAL = fn(RIGHT_FPVAL);
+	RIGHT_ADDRREFS = 0;	// result now is a non-address
 }


@ -895,6 +903,7 @@ static void perform_ranged_fp(double (*fn)(double))
 			Throw_error("Argument out of range.");
 		RIGHT_FPVAL = 0;
 	}
+	RIGHT_ADDRREFS = 0;	// result now is a non-address
 }


@ -918,7 +927,7 @@ static void both_ensure_int(int warn)
 		RIGHT_INTVAL = RIGHT_FPVAL;
 		RIGHT_FLAGS &= ~MVALUE_IS_FP;
 	}
-	// FIXME - "warn" is not used
+	// FIXME - warning is never seen if both operands are undefined in first pass!
 	Throw_first_pass_warning("Converted to integer for binary logic operator.");
 }

@ -993,9 +1002,14 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		goto remove_next_to_last_operator;

 // functions
+	case OPHANDLE_ADDR:
+		RIGHT_ADDRREFS = 1;	// result now is an address
+		goto remove_next_to_last_operator;
+
 	case OPHANDLE_INT:
 		if (RIGHT_FLAGS & MVALUE_IS_FP)
 			right_fp_to_int();
+		RIGHT_ADDRREFS = 0;	// result now is a non-address
 		goto remove_next_to_last_operator;

 	case OPHANDLE_FLOAT:
@ -1004,30 +1018,31 @@ static void try_to_reduce_stacks(int *open_parentheses)
 			RIGHT_FPVAL = RIGHT_INTVAL;
 			RIGHT_FLAGS |= MVALUE_IS_FP;
 		}
+		RIGHT_ADDRREFS = 0;	// result now is a non-address
 		goto remove_next_to_last_operator;

 	case OPHANDLE_SIN:
-		perform_fp(sin);
+		perform_fp(sin);	// also zeroes addr_refs
 		goto remove_next_to_last_operator;

 	case OPHANDLE_COS:
-		perform_fp(cos);
+		perform_fp(cos);	// also zeroes addr_refs
 		goto remove_next_to_last_operator;

 	case OPHANDLE_TAN:
-		perform_fp(tan);
+		perform_fp(tan);	// also zeroes addr_refs
 		goto remove_next_to_last_operator;

 	case OPHANDLE_ARCSIN:
-		perform_ranged_fp(asin);
+		perform_ranged_fp(asin);	// also zeroes addr_refs
 		goto remove_next_to_last_operator;

 	case OPHANDLE_ARCCOS:
-		perform_ranged_fp(acos);
+		perform_ranged_fp(acos);	// also zeroes addr_refs
 		goto remove_next_to_last_operator;

 	case OPHANDLE_ARCTAN:
-		perform_fp(atan);
+		perform_fp(atan);	// also zeroes addr_refs
 		goto remove_next_to_last_operator;

 // monadic operators
@ -1055,6 +1070,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		RIGHT_INTVAL = (RIGHT_INTVAL) & 255;
 		RIGHT_FLAGS |= MVALUE_ISBYTE;
 		RIGHT_FLAGS &= ~MVALUE_FORCEBITS;
+		RIGHT_ADDRREFS = 0;	// result now is a non-address
 		goto remove_next_to_last_operator;

 	case OPHANDLE_HIGHBYTEOF:
@ -1064,6 +1080,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		RIGHT_INTVAL = ((RIGHT_INTVAL) >> 8) & 255;
 		RIGHT_FLAGS |= MVALUE_ISBYTE;
 		RIGHT_FLAGS &= ~MVALUE_FORCEBITS;
+		RIGHT_ADDRREFS = 0;	// result now is a non-address
 		goto remove_next_to_last_operator;

 	case OPHANDLE_BANKBYTEOF:
@ -1073,6 +1090,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		RIGHT_INTVAL = ((RIGHT_INTVAL) >> 16) & 255;
 		RIGHT_FLAGS |= MVALUE_ISBYTE;
 		RIGHT_FLAGS &= ~MVALUE_FORCEBITS;
+		RIGHT_ADDRREFS = 0;	// result now is a non-address
 		goto remove_next_to_last_operator;

 // dyadic operators
@ -1080,6 +1098,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		if ((RIGHT_FLAGS | LEFT_FLAGS) & MVALUE_IS_FP) {
 			both_ensure_fp();
 			LEFT_FPVAL = pow(LEFT_FPVAL, RIGHT_FPVAL);
+			LEFT_ADDRREFS = 0;	// result now is a non-address
 			goto handle_flags_and_dec_stacks;
 		}

@ -1090,6 +1109,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 				Throw_error("Exponent is negative.");
 			LEFT_INTVAL = 0;
 		}
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_MULTIPLY:
@ -1099,6 +1119,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		} else {
 			LEFT_INTVAL *= RIGHT_INTVAL;
 		}
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_DIVIDE:
@ -1120,6 +1141,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 				LEFT_INTVAL = 0;
 			}
 		}
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_INTDIV:
@ -1142,6 +1164,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 				LEFT_INTVAL = 0;
 			}
 		}
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_MODULO:
@ -1154,6 +1177,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 				Throw_error(exception_div_by_zero);
 			LEFT_INTVAL = 0;
 		}
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_ADD:
@ -1163,6 +1187,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		} else {
 			LEFT_INTVAL += RIGHT_INTVAL;
 		}
+		LEFT_ADDRREFS += RIGHT_ADDRREFS;	// add address references
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_SUBTRACT:
@ -1172,6 +1197,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		} else {
 			LEFT_INTVAL -= RIGHT_INTVAL;
 		}
+		LEFT_ADDRREFS -= RIGHT_ADDRREFS;	// subtract address references
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_SL:
@ -1181,6 +1207,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 			LEFT_FPVAL *= pow(2.0, RIGHT_INTVAL);
 		else
 			LEFT_INTVAL <<= RIGHT_INTVAL;
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_ASR:
@ -1190,6 +1217,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 			LEFT_FPVAL /= (1 << RIGHT_INTVAL);
 		else
 			LEFT_INTVAL = my_asr(LEFT_INTVAL, RIGHT_INTVAL);
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_LSR:
@ -1197,6 +1225,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		if ((RIGHT_FLAGS | LEFT_FLAGS) & MVALUE_IS_FP)
 			both_ensure_int(TRUE);
 		LEFT_INTVAL = ((uintval_t) LEFT_INTVAL) >> RIGHT_INTVAL;
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_LE:
@ -1206,6 +1235,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		} else {
 			LEFT_INTVAL = (LEFT_INTVAL <= RIGHT_INTVAL);
 		}
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_LESSTHAN:
@ -1215,6 +1245,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		} else {
 			LEFT_INTVAL = (LEFT_INTVAL < RIGHT_INTVAL);
 		}
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_GE:
@ -1224,6 +1255,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		} else {
 			LEFT_INTVAL = (LEFT_INTVAL >= RIGHT_INTVAL);
 		}
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_GREATERTHAN:
@ -1233,6 +1265,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		} else {
 			LEFT_INTVAL = (LEFT_INTVAL > RIGHT_INTVAL);
 		}
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_NOTEQUAL:
@ -1242,6 +1275,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		} else {
 			LEFT_INTVAL = (LEFT_INTVAL != RIGHT_INTVAL);
 		}
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_EQUALS:
@ -1251,6 +1285,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		} else {
 			LEFT_INTVAL = (LEFT_INTVAL == RIGHT_INTVAL);
 		}
+		LEFT_ADDRREFS = 0;	// result now is a non-address
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_AND:
@ -1258,6 +1293,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		if ((RIGHT_FLAGS | LEFT_FLAGS) & MVALUE_IS_FP)
 			both_ensure_int(TRUE);
 		LEFT_INTVAL &= RIGHT_INTVAL;
+		LEFT_ADDRREFS += RIGHT_ADDRREFS;	// add address references
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_EOR:
@ -1268,6 +1304,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		if ((RIGHT_FLAGS | LEFT_FLAGS) & MVALUE_IS_FP)
 			both_ensure_int(TRUE);
 		LEFT_INTVAL ^= RIGHT_INTVAL;
+		LEFT_ADDRREFS += RIGHT_ADDRREFS;	// add address references
 		goto handle_flags_and_dec_stacks;

 	case OPHANDLE_OR:
@ -1275,6 +1312,7 @@ static void try_to_reduce_stacks(int *open_parentheses)
 		if ((RIGHT_FLAGS | LEFT_FLAGS) & MVALUE_IS_FP)
 			both_ensure_int(TRUE);
 		LEFT_INTVAL |= RIGHT_INTVAL;
+		LEFT_ADDRREFS += RIGHT_ADDRREFS;	// add address references
 		goto handle_flags_and_dec_stacks;

 	default:
@ -1389,8 +1427,7 @@ static int parse_expression(struct result_t *result)
 }


-// These functions handle numerical expressions. There are operators for
-// arithmetic, logic, shift and comparison operations.
+// These functions handle numerical expressions.
 // There are several different ways to call the core function:
 // intval_t ALU_any_int(void);
 //		returns int value (0 if result was undefined)
@ -1473,23 +1510,19 @@ int ALU_optional_defined_int(intval_t *target)
 // It the result's "exists" flag is clear (=empty expression), it throws an
 // error.
 // If the result's "defined" flag is clear, result_is_undefined() is called.
-void ALU_int_result(struct result_int_t *intresult)
+void ALU_int_result(struct result_t *intresult)
 {
-	struct result_t	result;
-
-	if (parse_expression(&result))
+	if (parse_expression(intresult))
 		Throw_error(exception_paren_open);
-	if ((result.flags & MVALUE_EXISTS) == 0)
-		Throw_error(exception_no_value);
-	else if ((result.flags & MVALUE_DEFINED) == 0)
-		result_is_undefined();
-	if (result.flags & MVALUE_IS_FP) {
-		intresult->intval = result.val.fpval;
-		intresult->flags = result.flags & ~MVALUE_IS_FP;
-	} else {
-		intresult->intval = result.val.intval;
-		intresult->flags = result.flags;
+	// make sure result is not float
+	if (intresult->flags & MVALUE_IS_FP) {
+		intresult->val.intval = intresult->val.fpval;
+		intresult->flags &= ~MVALUE_IS_FP;
 	}
+	if ((intresult->flags & MVALUE_EXISTS) == 0)
+		Throw_error(exception_no_value);
+	else if ((intresult->flags & MVALUE_DEFINED) == 0)
+		result_is_undefined();
 }


@ -1497,26 +1530,23 @@ void ALU_int_result(struct result_int_t *intresult)
 // This function allows for one '(' too many. Needed when parsing indirect
 // addressing modes where internal indices have to be possible. Returns number
 // of parentheses still open (either 0 or 1).
-int ALU_liberal_int(struct result_int_t *intresult)
+int ALU_liberal_int(struct result_t *intresult)
 {
-	struct result_t	result;
 	int	parentheses_still_open;

-	parentheses_still_open = parse_expression(&result);
+	parentheses_still_open = parse_expression(intresult);
+	// make sure result is not float
+	if (intresult->flags & MVALUE_IS_FP) {
+		intresult->val.intval = intresult->val.fpval;
+		intresult->flags &= ~MVALUE_IS_FP;
+	}
 	if (parentheses_still_open > 1) {
 		parentheses_still_open = 0;
 		Throw_error(exception_paren_open);
 	}
-	if ((result.flags & MVALUE_EXISTS)
-	&& ((result.flags & MVALUE_DEFINED) == 0))
+	if ((intresult->flags & MVALUE_EXISTS)
+	&& ((intresult->flags & MVALUE_DEFINED) == 0))
 		result_is_undefined();
-	if (result.flags & MVALUE_IS_FP) {
-		intresult->intval = result.val.fpval;
-		intresult->flags = result.flags & ~MVALUE_IS_FP;
-	} else {
-		intresult->intval = result.val.intval;
-		intresult->flags = result.flags;
-	}
 	return parentheses_still_open;
 }

--- a/src/alu.h
+++ b/src/alu.h
@ -1,5 +1,5 @@
 // ACME - a crossassembler for producing 6502/65c02/65816 code.
-// Copyright (C) 1998-2009 Marco Baye
+// Copyright (C) 1998-2014 Marco Baye
 // Have a look at "acme.c" for further info
 //
 // ALU stuff (the expression parser)
@ -12,9 +12,9 @@

 // constants

-// meaning of bits in "flags" of result_t and result_int_t structures:
+// meaning of bits in "flags" of result_t structure:
 #define MVALUE_IS_FP	(1u << 8)
-	// floating point value (never set in result_int_t)
+	// floating point value
 #define MVALUE_INDIRECT	(1u << 7)
 	// needless parentheses indicate use of indirect addressing modes
 #define MVALUE_EXISTS	(1u << 6)
@ -50,9 +50,9 @@ extern intval_t ALU_defined_int(void);
 // stores int value if given. Returns whether stored. Throws error if undefined.
 extern int ALU_optional_defined_int(intval_t *);
 // stores int value and flags (floats are transformed to int)
-extern void ALU_int_result(struct result_int_t *);
+extern void ALU_int_result(struct result_t *);
 // stores int value and flags, allowing for one '(' too many (x-indirect addr)
-extern int ALU_liberal_int(struct result_int_t *);
+extern int ALU_liberal_int(struct result_t *);
 // stores value and flags (result may be either int or float)
 extern void ALU_any_result(struct result_t *);

--- a/src/basics.c
+++ b/src/basics.c
@ -14,6 +14,7 @@
 #include "global.h"
 #include "output.h"
 #include "tree.h"
+#include "typesystem.h"


 // constants
@ -139,6 +140,19 @@ static enum eos PO_fill(void)
 }


+// force explicit label definitions to set "address" flag ("!addr"). Has to be re-entrant.
+static enum eos PO_addr(void)	// Now GotByte = illegal char
+{
+	SKIPSPACE();
+	if (GotByte == CHAR_SOB) {
+		typesystem_force_address_block();
+		return ENSURE_EOS;
+	}
+	typesystem_force_address_statement(TRUE);
+	return PARSE_REMAINDER;
+}
+
+
 // show user-defined message
 static enum eos throw_string(const char prefix[], void (*fn)(const char *))
 {
@ -240,6 +254,8 @@ static struct node_t	pseudo_opcodes[]	= {
 	PREDEFNODE("binary",	PO_binary),
 	PREDEFNODE("fi",	PO_fill),
 	PREDEFNODE("fill",	PO_fill),
+	PREDEFNODE("addr",	PO_addr),
+	PREDEFNODE("address",	PO_addr),
 //	PREDEFNODE("debug",	PO_debug),
 //	PREDEFNODE("info",	PO_info),
 //	PREDEFNODE("print",	PO_print),
--- a/src/config.h
+++ b/src/config.h
@ -18,11 +18,7 @@ struct result_t {	// either int or float
 		intval_t	intval;	// integer value
 		double		fpval;	// floating point value
 	} val;	// Expression value
-};
-// result structure type definition for int
-struct result_int_t {
-	int		flags;	// expression flags
-	intval_t	intval;	// expression value
+	int	addr_refs;	// address reference count (only look at this if value is DEFINED)
 };


--- a/src/cpu.c
+++ b/src/cpu.c
@ -75,7 +75,7 @@ static enum eos PO_align(void)
 	intval_t	and,
 			equal,
 			fill,
-			test	= CPU_state.pc.intval;
+			test	= CPU_state.pc.val.intval;

 	// make sure PC is defined.
 	if ((CPU_state.pc.flags & MVALUE_DEFINED) == 0) {
@ -152,13 +152,13 @@ static enum eos PO_pseudopc(void)

 	// set new
 	new_pc = ALU_defined_int();	// FIXME - allow for undefined!
-	new_offset = (new_pc - CPU_state.pc.intval) & 0xffff;
-	CPU_state.pc.intval = new_pc;
+	new_offset = (new_pc - CPU_state.pc.val.intval) & 0xffff;
+	CPU_state.pc.val.intval = new_pc;
 	CPU_state.pc.flags |= MVALUE_DEFINED;	// FIXME - remove when allowing undefined!
 	// if there's a block, parse that and then restore old value!
 	if (Parse_optional_block()) {
 		// restore old
-		CPU_state.pc.intval = (CPU_state.pc.intval - new_offset) & 0xffff;
+		CPU_state.pc.val.intval = (CPU_state.pc.val.intval - new_offset) & 0xffff;
 		CPU_state.pc.flags = outer_flags;
 	} else {
 		// not using a block is no longer allowed
--- a/src/flow.c
+++ b/src/flow.c
@ -209,12 +209,15 @@ static enum eos PO_for(void)	// Now GotByte = illegal char
 	first_arg = ALU_defined_int();
 	if (Input_accept_comma()) {
 		old_algo = FALSE;	// new format - yay!
+		if (!warn_on_old_for)
+			Throw_first_pass_warning("Found new \"!for\" syntax.");
 		counter_first = first_arg;	// use given argument
 		counter_last = ALU_defined_int();	// read second argument
 		counter_increment = (counter_last < counter_first) ? -1 : 1;
 	} else {
 		old_algo = TRUE;	// old format - booo!
-		Throw_first_pass_warning("Found deprecated \"!for\" syntax.");
+		if (warn_on_old_for)
+			Throw_first_pass_warning("Found old \"!for\" syntax.");
 		if (first_arg < 0)
 			Throw_serious_error("Loop count is negative.");
 		counter_first = 0;	// CAUTION - old algo pre-increments and therefore starts with 1!
--- a/src/global.c
+++ b/src/global.c
@ -5,6 +5,7 @@
 // Global stuff - things that are needed by several modules
 //  4 Oct 2006	Fixed a typo in a comment
 // 22 Nov 2007	Added warn_on_indented_labels
+//  2 Jun 2014	Added warn_on_old_for and warn_on_type_mismatch
 #include <stdio.h>
 #include "platform.h"
 #include "acme.h"
@ -17,6 +18,7 @@
 #include "output.h"
 #include "section.h"
 #include "tree.h"
+#include "typesystem.h"


 // constants
@ -55,7 +57,7 @@ const char	exception_syntax[]		= "Syntax error.";
 // ...4....	special character for input syntax: 0x00 TAB LF CR SPC : ; }
 // ....3...	preceding sequence of '-' characters is anonymous backward
 //		label. Currently only set for ')', ',' and CHAR_EOS.
-// .....210	unused
+// .....210	currently unused
 const char	Byte_flags[256]	= {
 /*$00*/	0x18, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,// control characters
 	0x00, 0x10, 0x10, 0x00, 0x00, 0x10, 0x00, 0x00,
@ -98,6 +100,8 @@ int		pass_count;			// number of current pass (starts 0)
 char		GotByte;			// Last byte read (processed)
 int		Process_verbosity	= 0;	// Level of additional output
 int		warn_on_indented_labels	= TRUE;	// warn if indented label is encountered
+int		warn_on_old_for		= TRUE;	// warn if "!for" with old syntax is found
+int		warn_on_type_mismatch	= FALSE;	// use type-checking system
 // global counters
 int		pass_undefined_count;	// "NeedValue" type errors
 int		pass_real_errors;	// Errors yet
@ -256,9 +260,10 @@ void Parse_until_eob_or_eof(void)
 	while ((GotByte != CHAR_EOB) && (GotByte != CHAR_EOF)) {
 		// process one statement
 		statement_flags = 0;	// no "label = pc" definition yet
+		typesystem_force_address_statement(FALSE);
 		// Parse until end of statement. Only loops if statement
 		// contains "label = pc" definition and something else; or
-		// if "!ifdef" is true.
+		// if "!ifdef" is true, or if "!addr" is used without block.
 		do {
 			switch (GotByte) {
 			case CHAR_EOS:	// end of statement
--- a/src/global.h
+++ b/src/global.h
@ -1,5 +1,5 @@
 // ACME - a crossassembler for producing 6502/65c02/65816 code.
-// Copyright (C) 1998-2009 Marco Baye
+// Copyright (C) 1998-2014 Marco Baye
 // Have a look at "acme.c" for further info
 //
 // Global stuff - things that are needed by several modules
@ -47,7 +47,7 @@ extern const char	Byte_flags[];
 			// converted to lower case by OR-ing this bit(!)
 #define BYTEIS_SYNTAX	(1u << 4)	// special character for input syntax
 #define FOLLOWS_ANON	(1u << 3)	// preceding '-' are backward label
-// bits 2, 1 and 0 are unused
+// bits 2, 1 and 0 are currently unused


 // Variables
@ -64,6 +64,8 @@ enum eos {
 extern int	pass_count;
 extern int	Process_verbosity;	// Level of additional output
 extern int	warn_on_indented_labels;	// warn if indented label is encountered
+extern int	warn_on_old_for;	// warn if "!for" with old syntax is found
+extern int	warn_on_type_mismatch;	// use type-checking system
 extern char	GotByte;	// Last byte read (processed)
 // Global counters
 extern int	pass_undefined_count;	// "NeedValue" type errors in current pass
--- a/src/label.c
+++ b/src/label.c
@ -17,6 +17,7 @@
 #include "platform.h"
 #include "section.h"
 #include "tree.h"
+#include "typesystem.h"


 // constants
@ -62,7 +63,7 @@ static void dump_one_label(struct node_ra_t *node, FILE *fd)
 }


-// Search for label. Create if nonexistant. If created, give it flags "Flags".
+// Search for label. Create if nonexistant. If created, give it flags "flags".
 // The label name must be held in GlobalDynaBuf.
 struct label *Label_find(zone_t zone, int flags)
 {
@ -78,6 +79,7 @@ struct label *Label_find(zone_t zone, int flags)
 		label = safe_malloc(sizeof(*label));
 		// Finish empty label item
 		label->result.flags = flags;
+		label->result.addr_refs = 0;
 		if (flags & MVALUE_IS_FP)
 			label->result.val.fpval = 0;
 		else
@ -206,8 +208,8 @@ static struct node_t	pseudo_opcodes[]	= {
 // GlobalDynaBuf holds the label name.
 void Label_implicit_definition(zone_t zone, int stat_flags, int force_bit, int change)
 {
-	struct result_int_t	pc;
-	struct result_t		result;
+	struct result_t	pc,
+			result;
 	struct label	*label;

 	label = Label_find(zone, force_bit);
@ -216,7 +218,8 @@ void Label_implicit_definition(zone_t zone, int stat_flags, int force_bit, int c
 		Throw_first_pass_warning("Implicit label definition not in leftmost column.");
 	vcpu_read_pc(&pc);
 	result.flags = pc.flags & MVALUE_DEFINED;
-	result.val.intval = pc.intval;
+	result.val.intval = pc.val.intval;
+	result.addr_refs = pc.addr_refs;
 	Label_set_value(label, &result, change);
 }

@ -236,6 +239,9 @@ void Label_parse_definition(zone_t zone, int stat_flags)
 		// label = parsed value
 		GetByte();	// skip '='
 		ALU_any_result(&result);
+		// if wanted, mark as address reference
+		if (typesystem_says_address())
+			result.addr_refs = 1;
 		Label_set_value(label, &result, FALSE);
 		Input_ensure_EOS();
 	} else {
--- a/src/mnemo.c
+++ b/src/mnemo.c
@ -11,6 +11,7 @@
 #include "input.h"
 #include "output.h"
 #include "tree.h"
+#include "typesystem.h"


 // Constants
@ -395,9 +396,9 @@ static int get_index(int next)
 	return addressing_mode;
 }

-// This function stores the command's argument in the given result_int_t
+// This function stores the command's argument in the given result_t
 // structure (using the valueparser). The addressing mode is returned.
-static int get_argument(struct result_int_t *result)
+static int get_argument(struct result_t *result)
 {
 	int	open_paren,
 		addressing_mode	= HAM_ABS;
@ -407,6 +408,7 @@ static int get_argument(struct result_int_t *result)
 	case '[':
 		GetByte();	// proceed with next char
 		ALU_int_result(result);
+		typesystem_want_addr(result);
 		if (GotByte == ']')
 			addressing_mode |= HAM_LIND | get_index(TRUE);
 		else
@ -416,10 +418,12 @@ static int get_argument(struct result_int_t *result)
 		GetByte();	// proceed with next char
 		addressing_mode |= HAM_IMM;
 		ALU_int_result(result);
+		typesystem_want_imm(result);
 		break;
 	default:
 		// liberal, to allow for "(...,"
 		open_paren = ALU_liberal_int(result);
+		typesystem_want_addr(result);
 		// check for implied addressing
 		if ((result->flags & MVALUE_EXISTS) == 0)
 			addressing_mode |= HAM_IMP;
@ -447,7 +451,7 @@ static int get_argument(struct result_int_t *result)

 // Helper function for calc_arg_size()
 // Only call with "size_bit = MVALUE_FORCE16" or "size_bit = MVALUE_FORCE24"
-static int check_oversize(int size_bit, struct result_int_t *argument)
+static int check_oversize(int size_bit, struct result_t *argument)
 {
 	// only check if value is *defined*
 	if ((argument->flags & MVALUE_DEFINED) == 0)
@ -456,11 +460,11 @@ static int check_oversize(int size_bit, struct result_int_t *argument)
 	// value is defined, so check
 	if (size_bit == MVALUE_FORCE16) {
 		// check 16-bit argument for high byte zero
-		if ((argument->intval <= 255) && (argument->intval >= -128))
+		if ((argument->val.intval <= 255) && (argument->val.intval >= -128))
 			Throw_warning(exception_highbyte_zero);
 	} else {
 		// check 24-bit argument for bank byte zero
-		if ((argument->intval <= 65535) && (argument->intval >= -32768))
+		if ((argument->val.intval <= 65535) && (argument->val.intval >= -32768))
 			Throw_warning(exception_highbyte_zero);
 	}
 	return size_bit;	// pass on result
@ -474,7 +478,7 @@ static int check_oversize(int size_bit, struct result_int_t *argument)
 // argument		value and flags of parameter
 // addressing_modes	adressing modes (8b, 16b, 24b or any combination)
 // Return value = force bit for number of parameter bytes to send (0 = error)
-static int calc_arg_size(int force_bit, struct result_int_t *argument, int addressing_modes)
+static int calc_arg_size(int force_bit, struct result_t *argument, int addressing_modes)
 {
 	// if there are no possible addressing modes, complain
 	if (addressing_modes == MAYBE______) {
@ -541,18 +545,18 @@ static int calc_arg_size(int force_bit, struct result_int_t *argument, int addre

 	// Value is sure, so use its own size
 	// if value is negative, size cannot be chosen. Complain!
-	if (argument->intval < 0) {
+	if (argument->val.intval < 0) {
 		Throw_error("Negative value - cannot choose addressing mode.");
 		return 0;
 	}

 	// Value is positive or zero. Check size ranges
 	// if there is an 8-bit addressing mode and value fits, use 8 bits
-	if ((addressing_modes & MVALUE_FORCE08) && (argument->intval < 256))
+	if ((addressing_modes & MVALUE_FORCE08) && (argument->val.intval < 256))
 		return MVALUE_FORCE08;

 	// if there is a 16-bit addressing mode and value fits, use 16 bits
-	if ((addressing_modes & MVALUE_FORCE16) && (argument->intval < 65536))
+	if ((addressing_modes & MVALUE_FORCE16) && (argument->val.intval < 65536))
 		return MVALUE_FORCE16;

 	// if there is a 24-bit addressing mode, use that. In case the
@ -584,16 +588,17 @@ static void not_in_bank(intval_t target)
 // Mnemonics using only 8bit relative addressing (short branch instructions).
 static void group_only_relative8_addressing(int opcode)
 {
-	struct result_int_t	target;
+	struct result_t	target;
 	intval_t	offset	= 0;	// dummy value, to not throw more errors than necessary

 	ALU_int_result(&target);
+	typesystem_want_addr(&target);
 	// FIXME - read pc via function call instead!
 	if (CPU_state.pc.flags & target.flags & MVALUE_DEFINED) {
-		if ((target.intval | 0xffff) != 0xffff) {
-			not_in_bank(target.intval);
+		if ((target.val.intval | 0xffff) != 0xffff) {
+			not_in_bank(target.val.intval);
 		} else {
-			offset = (target.intval - (CPU_state.pc.intval + 2)) & 0xffff;	// clip to 16 bit offset
+			offset = (target.val.intval - (CPU_state.pc.val.intval + 2)) & 0xffff;	// clip to 16 bit offset
 			// fix sign
 			if (offset & 0x8000)
 				offset -= 0x10000;
@ -618,16 +623,17 @@ static void group_only_relative8_addressing(int opcode)
 // Mnemonics using only 16bit relative addressing (BRL and PER).
 static void group_only_relative16_addressing(int opcode)
 {
-	struct result_int_t	target;
+	struct result_t	target;
 	intval_t	offset	= 0;	// dummy value, to not throw more errors than necessary

 	ALU_int_result(&target);
+	typesystem_want_addr(&target);
 	// FIXME - read pc via function call instead!
 	if (CPU_state.pc.flags & target.flags & MVALUE_DEFINED) {
-		if ((target.intval | 0xffff) != 0xffff) {
-			not_in_bank(target.intval);
+		if ((target.val.intval | 0xffff) != 0xffff) {
+			not_in_bank(target.val.intval);
 		} else {
-			offset = (target.intval - (CPU_state.pc.intval + 3)) & 0xffff;
+			offset = (target.val.intval - (CPU_state.pc.val.intval + 3)) & 0xffff;
 			// no further checks necessary, 16-bit branches can access whole bank
 		}
 	}
@ -638,7 +644,7 @@ static void group_only_relative16_addressing(int opcode)

 // set addressing mode bits depending on which opcodes exist, then calculate
 // argument size and output both opcode and argument
-static void make_command(int force_bit, struct result_int_t *result, unsigned long opcodes)
+static void make_command(int force_bit, struct result_t *result, unsigned long opcodes)
 {
 	int	addressing_modes	= MAYBE______;

@ -651,15 +657,15 @@ static void make_command(int force_bit, struct result_int_t *result, unsigned lo
 	switch (calc_arg_size(force_bit, result, addressing_modes)) {
 	case MVALUE_FORCE08:
 		Output_byte(opcodes & 255);
-		Output_8b(result->intval);
+		Output_8b(result->val.intval);
 		break;
 	case MVALUE_FORCE16:
 		Output_byte((opcodes >> 8) & 255);
-		Output_16b(result->intval);
+		Output_16b(result->val.intval);
 		break;
 	case MVALUE_FORCE24:
 		Output_byte((opcodes >> 16) & 255);
-		Output_24b(result->intval);
+		Output_24b(result->val.intval);
 	}
 }

@ -689,7 +695,7 @@ static unsigned int imm_ops(int *force_bit, unsigned char opcode, int imm_flag)
 static void group_main(int index, int imm_flag)
 {
 	unsigned long	imm_opcodes;
-	struct result_int_t	result;
+	struct result_t	result;
 	int		force_bit	= Input_get_force_bit();	// skips spaces after

 	switch (get_argument(&result)) {
@ -738,7 +744,7 @@ static void group_main(int index, int imm_flag)
 static void group_misc(int index, int imm_flag)
 {
 	unsigned long	imm_opcodes;
-	struct result_int_t	result;
+	struct result_t	result;
 	int		force_bit	= Input_get_force_bit();	// skips spaces after

 	switch (get_argument(&result)) {
@ -755,7 +761,7 @@ static void group_misc(int index, int imm_flag)
 		make_command(force_bit, &result, imm_opcodes);
 		// check whether to warn about 6510's unstable LXA
 		if ((imm_opcodes == 0xab)
-		&& ((result.intval & 0xff) != 0x00)
+		&& ((result.val.intval & 0xff) != 0x00)
 		&& (result.flags & MVALUE_DEFINED)
 		&& (CPU_state.type->flags & CPUFLAG_AB_NEEDS_0_ARG))
 			Throw_warning("Assembling unstable LXA #NONZERO instruction");
@ -796,7 +802,7 @@ static void group_move(int opcode)
 // The jump instructions.
 static void group_jump(int index)
 {
-	struct result_int_t	result;
+	struct result_t	result;
 	int		force_bit	= Input_get_force_bit();	// skips spaces after

 	switch (get_argument(&result)) {
@ -806,7 +812,7 @@ static void group_jump(int index)
 	case HAM_IND:	// ($ffff)
 		make_command(force_bit, &result, jump_ind[index]);
 		// check whether to warn about 6502's JMP() bug
-		if (((result.intval & 0xff) == 0xff)
+		if (((result.val.intval & 0xff) == 0xff)
 		&& (result.flags & MVALUE_DEFINED)
 		&& (CPU_state.type->flags & CPUFLAG_INDIRECTJMPBUGGY))
 			Throw_warning("Assembling buggy JMP($xxff) instruction");
--- a/src/output.c
+++ b/src/output.c
@ -485,7 +485,7 @@ void Output_passinit(void)

 	//vcpu stuff:
 	CPU_state.pc.flags = 0;	// not defined yet
-	CPU_state.pc.intval = 0;	// same as output's write_idx on pass init
+	CPU_state.pc.val.intval = 0;	// same as output's write_idx on pass init
 	CPU_state.add_to_pc = 0;	// increase PC by this at end of statement
 	CPU_state.a_is_long = FALSE;	// short accu
 	CPU_state.xy_are_long = FALSE;	// short index regs
@ -554,9 +554,10 @@ void vcpu_set_pc(intval_t new_pc, int segment_flags)
 {
 	intval_t	new_offset;

-	new_offset = (new_pc - CPU_state.pc.intval) & 0xffff;
-	CPU_state.pc.intval = new_pc;
+	new_offset = (new_pc - CPU_state.pc.val.intval) & 0xffff;
+	CPU_state.pc.val.intval = new_pc;
 	CPU_state.pc.flags |= MVALUE_DEFINED;	// FIXME - remove when allowing undefined!
+	CPU_state.pc.addr_refs = 1;	// yes, PC counts as address
 	// now tell output buffer to start a new segment
 	Output_start_segment(new_offset, segment_flags);
 }
@ -614,7 +615,7 @@ void PO_setpc(void)


 // get program counter
-void vcpu_read_pc(struct result_int_t *target)
+void vcpu_read_pc(struct result_t *target)
 {
 	*target = CPU_state.pc;
 }
@ -630,6 +631,6 @@ int vcpu_get_statement_size(void)
 // adjust program counter (called at end of each statement)
 void vcpu_end_statement(void)
 {
-	CPU_state.pc.intval = (CPU_state.pc.intval + CPU_state.add_to_pc) & 0xffff;
+	CPU_state.pc.val.intval = (CPU_state.pc.val.intval + CPU_state.add_to_pc) & 0xffff;
 	CPU_state.add_to_pc = 0;
 }
--- a/src/output.h
+++ b/src/output.h
@ -19,7 +19,7 @@
 // FIXME - move struct definition to .c file and change other .c files' accesses to fn calls
 struct vcpu {
 	const struct cpu_type	*type;		// current CPU type (default 6502)	(FIXME - move out of struct again?)
-	struct result_int_t	pc;		// current program counter (pseudo value)
+	struct result_t		pc;		// current program counter (pseudo value)
 	int			add_to_pc;	// add to PC after statement
 	int			a_is_long;
 	int			xy_are_long;
@ -65,7 +65,7 @@ extern void Output_end_segment(void);
 // set program counter to defined value (FIXME - allow undefined!)
 extern void vcpu_set_pc(intval_t new_pc, int flags);
 // get program counter
-extern void vcpu_read_pc(struct result_int_t *target);
+extern void vcpu_read_pc(struct result_t *target);
 // get size of current statement (until now) - needed for "!bin" verbose output
 extern int vcpu_get_statement_size(void);
 // adjust program counter (called at end of each statement)
--- a/src/typesystem.c
+++ b/src/typesystem.c
@ -0,0 +1,53 @@
+// ACME - a crossassembler for producing 6502/65c02/65816 code.
+// Copyright (C) 1998-2014 Marco Baye
+// Have a look at "acme.c" for further info
+//
+// Type system stuff
+#include "typesystem.h"
+#include "config.h"
+#include "alu.h"
+#include "global.h"
+
+
+static int	in_address_block	= FALSE;
+static int	in_address_statement	= FALSE;
+
+// Functions
+
+int typesystem_says_address(void)
+{
+	return in_address_block | in_address_statement;
+}
+
+void typesystem_force_address_block(void)
+{
+	int	buffer	= in_address_block;
+
+	in_address_block = TRUE;
+	Parse_optional_block();
+	in_address_block = buffer;
+}
+
+void typesystem_force_address_statement(int value)
+{
+	in_address_statement = value;
+}
+
+void typesystem_want_imm(struct result_t *result)
+{
+	if (!warn_on_type_mismatch)
+		return;
+	if (!(result->flags & MVALUE_DEFINED))
+		return;
+	if (result->addr_refs != 0)
+		Throw_warning("Wrong type - expected integer.");
+}
+void typesystem_want_addr(struct result_t *result)
+{
+	if (!warn_on_type_mismatch)
+		return;
+	if (!(result->flags & MVALUE_DEFINED))
+		return;
+	if (result->addr_refs != 1)
+		Throw_warning("Wrong type - expected address.");
+}
--- a/src/typesystem.h
+++ b/src/typesystem.h
@ -0,0 +1,25 @@
+// ACME - a crossassembler for producing 6502/65c02/65816 code.
+// Copyright (C) 1998-2014 Marco Baye
+// Have a look at "acme.c" for further info
+//
+// Type system stuff
+#ifndef typesystem_H
+#define typesystem_H
+
+
+#include "config.h"
+
+
+// return whether explicit label definitions should force "address" mode
+extern int typesystem_says_address(void);
+// parse a block while forcing address mode
+extern void typesystem_force_address_block(void);
+// force address mode on or off for the next statement
+extern void typesystem_force_address_statement(int value);
+// warn if result is address instead of integer
+extern void typesystem_want_imm(struct result_t *result);
+// warn if result is integer instead of address
+extern void typesystem_want_addr(struct result_t *result);
+
+
+#endif