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prog8/prog8lib/c64utils.p8
Irmen de Jong 8f26fdef61 changed the syntax of kernel/asm subroutines
2018-10-01 20:05:32 +02:00

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; Prog8 definitions for the Commodore-64
; These are the utility subroutines.
;
; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
;
; indent format: TABS, size=8
%import c64lib
~ c64utils {
; ----- utility functions ----
asmsub init_system () -> clobbers(A,X,Y) -> () {
; ---- initializes the machine to a sane starting state
; This means that the BASIC, KERNAL and CHARGEN ROMs are banked in,
; the VIC, SID and CIA chips are reset, screen is cleared, and the default IRQ is set.
; Also a different color scheme is chosen to identify ourselves a little.
%asm {{
sei
cld
lda #%00101111
sta $00
lda #%00100111
sta $01
jsr c64.IOINIT
jsr c64.RESTOR
jsr c64.CINT
lda #6
sta c64.EXTCOL
lda #7
sta c64.COLOR
lda #0
sta c64.BGCOL0
tax
tay
clc
clv
cli
rts
}}
}
asmsub byte2decimal (ubyte: byte @ A) -> clobbers() -> (byte @ Y, byte @ X, byte @ A) {
; ---- A to decimal string in Y/X/A (100s in Y, 10s in X, 1s in A)
%asm {{
ldy #$2f
ldx #$3a
sec
- iny
sbc #100
bcs -
- dex
adc #10
bmi -
adc #$2f
rts
}}
}
asmsub byte2hex (ubyte: byte @ A) -> clobbers(A) -> (byte @ X, byte @ Y) {
; ---- A to hex string in XY (first hex char in X, second hex char in Y)
%asm {{
pha
and #$0f
tax
ldy hex_digits,x
pla
lsr a
lsr a
lsr a
lsr a
tax
lda hex_digits,x
tax
rts
hex_digits .str "0123456789abcdef" ; can probably be reused for other stuff as well
}}
}
str word2hex_output = "1234" ; 0-terminated, to make printing easier
asmsub word2hex (dataword: word @ XY) -> clobbers(A,X,Y) -> () {
; ---- convert 16 bit word in X/Y into 4-character hexadecimal string into memory 'word2hex_output'
%asm {{
stx c64.SCRATCH_ZP2
tya
jsr byte2hex
stx word2hex_output
sty word2hex_output+1
lda c64.SCRATCH_ZP2
jsr byte2hex
stx word2hex_output+2
sty word2hex_output+3
rts
}}
}
byte[3] word2bcd_bcdbuff = [0, 0, 0]
asmsub word2bcd (dataword: word @ XY) -> clobbers(A,X) -> () {
; Convert an 16 bit binary value to BCD
;
; This function converts a 16 bit binary value in X/Y into a 24 bit BCD. It
; works by transferring one bit a time from the source and adding it
; into a BCD value that is being doubled on each iteration. As all the
; arithmetic is being done in BCD the result is a binary to decimal
; conversion.
%asm {{
stx c64.SCRATCH_ZP1
sty c64.SCRATCH_ZP2
sed ; switch to decimal mode
lda #0 ; ensure the result is clear
sta word2bcd_bcdbuff+0
sta word2bcd_bcdbuff+1
sta word2bcd_bcdbuff+2
ldx #16 ; the number of source bits
- asl c64.SCRATCH_ZP1 ; shift out one bit
rol c64.SCRATCH_ZP2
lda word2bcd_bcdbuff+0 ; and add into result
adc word2bcd_bcdbuff+0
sta word2bcd_bcdbuff+0
lda word2bcd_bcdbuff+1 ; propagating any carry
adc word2bcd_bcdbuff+1
sta word2bcd_bcdbuff+1
lda word2bcd_bcdbuff+2 ; ... thru whole result
adc word2bcd_bcdbuff+2
sta word2bcd_bcdbuff+2
dex ; and repeat for next bit
bne -
cld ; back to binary
rts
}}
}
byte[5] word2decimal_output = 0
asmsub word2decimal (dataword: word @ XY) -> clobbers(A,X,Y) -> () {
; ---- convert 16 bit word in X/Y into decimal string into memory 'word2decimal_output'
%asm {{
jsr word2bcd
lda word2bcd_bcdbuff+2
clc
adc #'0'
sta word2decimal_output
ldy #1
lda word2bcd_bcdbuff+1
jsr +
lda word2bcd_bcdbuff+0
+ pha
lsr a
lsr a
lsr a
lsr a
clc
adc #'0'
sta word2decimal_output,y
iny
pla
and #$0f
adc #'0'
sta word2decimal_output,y
iny
rts
}}
}
; @todo string to 32 bit unsigned integer http://www.6502.org/source/strings/ascii-to-32bit.html
} ; ------ end of block c64utils
~ c64flt {
; ---- this block contains C-64 floating point related functions ----
asmsub FREADS32 () -> clobbers(A,X,Y) -> () {
; ---- fac1 = signed int32 from $62-$65 big endian (MSB FIRST)
%asm {{
lda $62
eor #$ff
asl a
lda #0
ldx #$a0
jmp $bc4f ; internal BASIC routine
}}
}
asmsub FREADUS32 () -> clobbers(A,X,Y) -> () {
; ---- fac1 = uint32 from $62-$65 big endian (MSB FIRST)
%asm {{
sec
lda #0
ldx #$a0
jmp $bc4f ; internal BASIC routine
}}
}
asmsub FREADS24AXY (lo: byte @ A, mid: byte @ X, hi: byte @ Y) -> clobbers(A,X,Y) -> () {
; ---- fac1 = signed int24 (A/X/Y contain lo/mid/hi bytes)
; note: there is no FREADU24AXY (unsigned), use FREADUS32 instead.
%asm {{
sty $62
stx $63
sta $64
lda $62
eor #$FF
asl a
lda #0
sta $65
ldx #$98
jmp $bc4f ; internal BASIC routine
}}
}
asmsub GIVUAYF (uword: word @ AY) -> clobbers(A,X,Y) -> () {
; ---- unsigned 16 bit word in A/Y (lo/hi) to fac1
%asm {{
sty $62
sta $63
ldx #$90
sec
jmp $bc49 ; internal BASIC routine
}}
}
asmsub GIVAYFAY (sword: word @ AY) -> clobbers(A,X,Y) -> () {
; ---- signed 16 bit word in A/Y (lo/hi) to float in fac1
%asm {{
sta c64.SCRATCH_ZP1
tya
ldy c64.SCRATCH_ZP1
jmp c64.GIVAYF ; this uses the inverse order, Y/A
}}
}
asmsub FTOSWRDAY () -> clobbers(X) -> (word @ AY) {
; ---- fac1 to signed word in A/Y
%asm {{
jsr c64.FTOSWORDYA ; note the inverse Y/A order
sta c64.SCRATCH_ZP1
tya
ldy c64.SCRATCH_ZP1
rts
}}
}
asmsub GETADRAY () -> clobbers(X) -> (word @ AY) {
; ---- fac1 to unsigned word in A/Y
%asm {{
jsr c64.GETADR ; this uses the inverse order, Y/A
sta c64.SCRATCH_ZP1
tya
ldy c64.SCRATCH_ZP1
rts
}}
}
asmsub copy_mflt (source: word @ XY) -> clobbers(A,Y) -> () {
; ---- copy a 5 byte MFLT floating point variable to another place
; input: X/Y = source address, c64.SCRATCH_ZPWORD1 = destination address
%asm {{
stx c64.SCRATCH_ZP1
sty c64.SCRATCH_ZPWORD1+1
ldy #0
lda (c64.SCRATCH_ZP1),y
sta (c64.SCRATCH_ZPWORD1),y
iny
lda (c64.SCRATCH_ZP1),y
sta (c64.SCRATCH_ZPWORD1),y
iny
lda (c64.SCRATCH_ZP1),y
sta (c64.SCRATCH_ZPWORD1),y
iny
lda (c64.SCRATCH_ZP1),y
sta (c64.SCRATCH_ZPWORD1),y
iny
lda (c64.SCRATCH_ZP1),y
sta (c64.SCRATCH_ZPWORD1),y
ldy c64.SCRATCH_ZPWORD1+1
rts
}}
}
asmsub float_add_one (mflt: word @ XY) -> clobbers(A,X,Y) -> () {
; ---- add 1 to the MFLT pointed to by X/Y. Clobbers A, X, Y
%asm {{
stx c64.SCRATCH_ZP1
sty c64.SCRATCH_ZP2
txa
jsr c64.MOVFM ; fac1 = float XY
lda #<c64.FL_FONE
ldy #>c64.FL_FONE
jsr c64.FADD ; fac1 += 1
ldx c64.SCRATCH_ZP1
ldy c64.SCRATCH_ZP2
jmp c64.FTOMEMXY ; float XY = fac1
}}
}
asmsub float_sub_one (mflt: word @ XY) -> clobbers(A,X,Y) -> () {
; ---- subtract 1 from the MFLT pointed to by X/Y. Clobbers A, X, Y
%asm {{
stx c64.SCRATCH_ZP1
sty c64.SCRATCH_ZP2
lda #<c64.FL_FONE
ldy #>c64.FL_FONE
jsr c64.MOVFM ; fac1 = 1
txa
ldy c64.SCRATCH_ZP2
jsr c64.FSUB ; fac1 = float XY - 1
ldx c64.SCRATCH_ZP1
ldy c64.SCRATCH_ZP2
jmp c64.FTOMEMXY ; float XY = fac1
}}
}
asmsub float_add_SW1_to_XY (mflt: word @ XY) -> clobbers(A,X,Y) -> () {
; ---- add MFLT pointed to by SCRATCH_ZPWORD1 to the MFLT pointed to by X/Y. Clobbers A, X, Y
%asm {{
stx c64.SCRATCH_ZP1
sty c64.SCRATCH_ZP2
txa
jsr c64.MOVFM ; fac1 = float XY
lda c64.SCRATCH_ZPWORD1
ldy c64.SCRATCH_ZPWORD1+1
jsr c64.FADD ; fac1 += SCRATCH_ZPWORD1
ldx c64.SCRATCH_ZP1
ldy c64.SCRATCH_ZP2
jmp c64.FTOMEMXY ; float XY = fac1
}}
}
asmsub float_sub_SW1_from_XY (mflt: word @ XY) -> clobbers(A,X,Y) -> () {
; ---- subtract MFLT pointed to by SCRATCH_ZPWORD1 from the MFLT pointed to by X/Y. Clobbers A, X, Y
%asm {{
stx c64.SCRATCH_ZP1
sty c64.SCRATCH_ZP2
lda c64.SCRATCH_ZPWORD1
ldy c64.SCRATCH_ZPWORD1+1
jsr c64.MOVFM ; fac1 = SCRATCH_ZPWORD1
txa
ldy c64.SCRATCH_ZP2
jsr c64.FSUB ; fac1 = float XY - SCRATCH_ZPWORD1
ldx c64.SCRATCH_ZP1
ldy c64.SCRATCH_ZP2
jmp c64.FTOMEMXY ; float XY = fac1
}}
}
} ; ------ end of block c64flt
~ c64scr {
; ---- this block contains (character) Screen and text I/O related functions ----
asmsub clear_screen (char: byte @ A, color: byte @ Y) -> clobbers() -> () {
; ---- clear the character screen with the given fill character and character color.
; (assumes screen is at $0400, could be altered in the future with self-modifying code)
; @todo some byte var to set the SCREEN ADDR HI BYTE
%asm {{
sta _loop + 1 ; self-modifying
stx c64.SCRATCH_ZP1
ldx #0
_loop lda #0
sta c64.Screen,x
sta c64.Screen+$0100,x
sta c64.Screen+$0200,x
sta c64.Screen+$02e8,x
tya
sta c64.Colors,x
sta c64.Colors+$0100,x
sta c64.Colors+$0200,x
sta c64.Colors+$02e8,x
inx
bne _loop
lda _loop+1 ; restore A and X
ldx c64.SCRATCH_ZP1
rts
}}
}
asmsub scroll_left_full (alsocolors: byte @ Pc) -> clobbers(A, X, Y) -> () {
; ---- scroll the whole screen 1 character to the left
; contents of the rightmost column are unchanged, you should clear/refill this yourself
; Carry flag determines if screen color data must be scrolled too
%asm {{
bcs +
jmp _scroll_screen
+ ; scroll the color memory
ldx #0
ldy #38
-
.for row=0, row<=12, row+=1
lda c64.Colors + 40*row + 1,x
sta c64.Colors + 40*row,x
.next
inx
dey
bpl -
ldx #0
ldy #38
-
.for row=13, row<=24, row+=1
lda c64.Colors + 40*row + 1,x
sta c64.Colors + 40*row,x
.next
inx
dey
bpl -
_scroll_screen ; scroll the screen memory
ldx #0
ldy #38
-
.for row=0, row<=12, row+=1
lda c64.Screen + 40*row + 1,x
sta c64.Screen + 40*row,x
.next
inx
dey
bpl -
ldx #0
ldy #38
-
.for row=13, row<=24, row+=1
lda c64.Screen + 40*row + 1,x
sta c64.Screen + 40*row,x
.next
inx
dey
bpl -
rts
}}
}
asmsub scroll_right_full (alsocolors: byte @ Pc) -> clobbers(A,X) -> () {
; ---- scroll the whole screen 1 character to the right
; contents of the leftmost column are unchanged, you should clear/refill this yourself
; Carry flag determines if screen color data must be scrolled too
%asm {{
bcs +
jmp _scroll_screen
+ ; scroll the color memory
ldx #38
-
.for row=0, row<=12, row+=1
lda c64.Colors + 40*row + 0,x
sta c64.Colors + 40*row + 1,x
.next
dex
bpl -
ldx #38
-
.for row=13, row<=24, row+=1
lda c64.Colors + 40*row,x
sta c64.Colors + 40*row + 1,x
.next
dex
bpl -
_scroll_screen ; scroll the screen memory
ldx #38
-
.for row=0, row<=12, row+=1
lda c64.Screen + 40*row + 0,x
sta c64.Screen + 40*row + 1,x
.next
dex
bpl -
ldx #38
-
.for row=13, row<=24, row+=1
lda c64.Screen + 40*row,x
sta c64.Screen + 40*row + 1,x
.next
dex
bpl -
rts
}}
}
asmsub scroll_up_full (alsocolors: byte @ Pc) -> clobbers(A,X) -> () {
; ---- scroll the whole screen 1 character up
; contents of the bottom row are unchanged, you should refill/clear this yourself
; Carry flag determines if screen color data must be scrolled too
%asm {{
bcs +
jmp _scroll_screen
+ ; scroll the color memory
ldx #39
-
.for row=1, row<=11, row+=1
lda c64.Colors + 40*row,x
sta c64.Colors + 40*(row-1),x
.next
dex
bpl -
ldx #39
-
.for row=12, row<=24, row+=1
lda c64.Colors + 40*row,x
sta c64.Colors + 40*(row-1),x
.next
dex
bpl -
_scroll_screen ; scroll the screen memory
ldx #39
-
.for row=1, row<=11, row+=1
lda c64.Screen + 40*row,x
sta c64.Screen + 40*(row-1),x
.next
dex
bpl -
ldx #39
-
.for row=12, row<=24, row+=1
lda c64.Screen + 40*row,x
sta c64.Screen + 40*(row-1),x
.next
dex
bpl -
rts
}}
}
asmsub scroll_down_full (alsocolors: byte @ Pc) -> clobbers(A,X) -> () {
; ---- scroll the whole screen 1 character down
; contents of the top row are unchanged, you should refill/clear this yourself
; Carry flag determines if screen color data must be scrolled too
%asm {{
bcs +
jmp _scroll_screen
+ ; scroll the color memory
ldx #39
-
.for row=23, row>=12, row-=1
lda c64.Colors + 40*row,x
sta c64.Colors + 40*(row+1),x
.next
dex
bpl -
ldx #39
-
.for row=11, row>=0, row-=1
lda c64.Colors + 40*row,x
sta c64.Colors + 40*(row+1),x
.next
dex
bpl -
_scroll_screen ; scroll the screen memory
ldx #39
-
.for row=23, row>=12, row-=1
lda c64.Screen + 40*row,x
sta c64.Screen + 40*(row+1),x
.next
dex
bpl -
ldx #39
-
.for row=11, row>=0, row-=1
lda c64.Screen + 40*row,x
sta c64.Screen + 40*(row+1),x
.next
dex
bpl -
rts
}}
}
asmsub print_string (address: word @ XY) -> clobbers(A,Y) -> () {
; ---- print null terminated string from X/Y
; note: the compiler contains an optimization that will replace
; a call to this subroutine with a string argument of just one char,
; by just one call to c64.CHROUT of that single char.
%asm {{
stx c64.SCRATCH_ZP1
sty c64.SCRATCH_ZP2
ldy #0
- lda (c64.SCRATCH_ZP1),y
beq +
jsr c64.CHROUT
iny
bne -
+ rts
}}
}
asmsub print_pstring (address: word @ XY) -> clobbers(A,X) -> (byte @ Y) {
; ---- print pstring (length as first byte) from X/Y, returns str len in Y
%asm {{
stx c64.SCRATCH_ZP1
sty c64.SCRATCH_ZP2
ldy #0
lda (c64.SCRATCH_ZP1),y
beq +
tax
- iny
lda (c64.SCRATCH_ZP1),y
jsr c64.CHROUT
dex
bne -
+ rts ; output string length is in Y
}}
}
asmsub print_pimmediate () -> clobbers() -> () {
; ---- print pstring in memory immediately following the subroutine fast call instruction
; note that the clobbered registers (A,X,Y) are not listed ON PURPOSE
%asm {{
tsx
lda $102,x
tay ; put high byte in y
lda $101,x
tax ; and low byte in x.
inx
bne +
iny
+ jsr print_pstring ; print string in XY, returns string length in y.
tya
tsx
clc
adc $101,x ; add content of 1st (length) byte to return addr.
bcc + ; if that made the low byte roll over to 00,
inc $102,x ; then increment the high byte too.
+ clc
adc #1 ; now add 1 for the length byte itself.
sta $101,x
bne + ; if that made it (the low byte) roll over to 00,
inc $102,x ; increment the high byte of the return addr too.
+ rts
}}
}
asmsub print_byte_decimal0 (ubyte: byte @ A) -> clobbers(A,X,Y) -> () {
; ---- print the byte in A in decimal form, with left padding 0s (3 positions total)
%asm {{
jsr byte2decimal
pha
tya
jsr c64.CHROUT
txa
jsr c64.CHROUT
pla
jmp c64.CHROUT
}}
}
asmsub print_byte_decimal (ubyte: byte @ A) -> clobbers(A,X,Y) -> () {
; ---- print the byte in A in decimal form, without left padding 0s
%asm {{
jsr byte2decimal
pha
cpy #'0'
bne _print_hundreds
cpx #'0'
bne _print_tens
pla
jmp c64.CHROUT
_print_hundreds tya
jsr c64.CHROUT
_print_tens txa
jsr c64.CHROUT
pla
jmp c64.CHROUT
}}
}
asmsub print_byte_hex (prefix: byte @ Pc, ubyte: byte @ A) -> clobbers(A,X,Y) -> () {
; ---- print the byte in A in hex form (if Carry is set, a radix prefix '$' is printed as well)
%asm {{
bcc +
pha
lda #'$'
jsr c64.CHROUT
pla
+ jsr byte2hex
txa
jsr c64.CHROUT
tya
jmp c64.CHROUT
}}
}
asmsub print_word_hex (prefix: byte @ Pc, dataword: word @ XY) -> clobbers(A,X,Y) -> () {
; ---- print the (unsigned) word in X/Y in hexadecimal form (4 digits)
; (if Carry is set, a radix prefix '$' is printed as well)
%asm {{
stx c64.SCRATCH_ZP1
tya
jsr print_byte_hex
lda c64.SCRATCH_ZP1
clc
jmp print_byte_hex
}}
}
asmsub print_word_decimal0 (dataword: word @ XY) -> clobbers(A,X,Y) -> () {
; ---- print the (unsigned) word in X/Y in decimal form, with left padding 0s (5 positions total)
%asm {{
jsr word2decimal
lda word2decimal_output
jsr c64.CHROUT
lda word2decimal_output+1
jsr c64.CHROUT
lda word2decimal_output+2
jsr c64.CHROUT
lda word2decimal_output+3
jsr c64.CHROUT
lda word2decimal_output+4
jmp c64.CHROUT
}}
}
asmsub print_word_decimal (dataword: word @ XY) -> clobbers(A,X,Y) -> () {
; ---- print the word in X/Y in decimal form, without left padding 0s
%asm {{
jsr word2decimal
ldy #0
lda word2decimal_output
cmp #'0'
bne _pr_decimal
iny
lda word2decimal_output+1
cmp #'0'
bne _pr_decimal
iny
lda word2decimal_output+2
cmp #'0'
bne _pr_decimal
iny
lda word2decimal_output+3
cmp #'0'
bne _pr_decimal
iny
_pr_decimal
lda word2decimal_output,y
jsr c64.CHROUT
iny
cpy #5
bcc _pr_decimal
rts
}}
}
asmsub input_chars (buffer: word @ AX) -> clobbers(A) -> (byte @ Y) {
; ---- Input a string (max. 80 chars) from the keyboard.
; It assumes the keyboard is selected as I/O channel!!
%asm {{
sta c64.SCRATCH_ZP1
stx c64.SCRATCH_ZP2
ldy #0 ; char counter = 0
- jsr c64.CHRIN
cmp #$0d ; return (ascii 13) pressed?
beq + ; yes, end.
sta (c64.SCRATCH_ZP1),y ; else store char in buffer
iny
bne -
+ lda #0
sta (c64.SCRATCH_ZP1),y ; finish string with 0 byte
rts
}}
}
} ; ---- end block c64scr
;asmsub memcopy_basic () -> clobbers(A,X,Y) -> () {
; ; ---- copy a memory block by using a BASIC ROM routine
; ; it calls a function from the basic interpreter, so:
; ; - BASIC ROM must be banked in
; ; - the source block must be readable (so no RAM hidden under BASIC, Kernal, or I/O)
; ; - the target block must be writable (so no RAM hidden under I/O)
; ; higher addresses are copied first, so:
; ; - moving data to higher addresses works even if areas overlap
; ; - moving data to lower addresses only works if areas do not overlap
; %asm {{
; lda #<src_start
; ldx #>src_start
; sta $5f
; stx $60
; lda #<src_end
; ldx #>src_end
; sta $5a
; stx $5b
; lda #<(target_start + src_end - src_start)
; ldx #>(target_start + src_end - src_start)
; sta $58
; stx $59
; jmp $a3bf
; }
;}
; macro version of the above memcopy_basic routine:
; MACRO PARAMS src_start, src_end, target_start
; lda #<src_start
; ldx #>src_start
; sta $5f
; stx $60
; lda #<src_end
; ldx #>src_end
; sta $5a
; stx $5b
; lda #<(target_start + src_end - src_start)
; ldx #>(target_start + src_end - src_start)
; sta $58
; stx $59
; jsr $a3bf
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