Add CRTC EhBASIC, switch char rom.

samples/ehbasic_crtc/.gitignore

@@ -0,0 +1,4 @@
+*.rom
+*.lst
+*.map
+*.o

samples/ehbasic_crtc/Makefile

@@ -0,0 +1,13 @@
+CA=ca65
+LD=ld65
+
+all: ehbasic
+
+ehbasic: ehbasic.o
+	$(LD) -C symon.config -vm -m ehbasic.map -o ehbasic.rom ehbasic.o
+
+ehbasic.o:
+	$(CA) --listing -o ehbasic.o min_mon.asm
+
+clean:
+	rm -f *.o *.rom *.map *.lst

samples/ehbasic_crtc/README.txt

@@ -0,0 +1,85 @@
+This directoy contains a very slightly modified version of EhBASIC 2.22
+to support the Symon simulator.
+
+Usage
+-----
+
+The pre-assemled ROM image 'ehbasic.rom' in the "samples" directory is all you
+need unless you want to rebuild this source code.
+
+Just copy the image 'ehbasic.rom' to the directory where you run Symon, and
+rename the file to 'rom.bin'. It will be loaded at memory location $D000 when
+the simulator starts up. Click "Run" and you'll be presented with BASIC.
+
+At the first prompt, type 'C' for a Cold Start
+
+When prompted for free memory, type: $C000
+
+Note that EhBASIC only accepts upper case input, so you'll need to use caps
+lock (the cruise control for cool) to really make the most of it.
+
+
+Building
+--------
+
+
+To build it, you'll need the CC65 tool chain from http://www.cc65.org/
+and a suitable version of 'make'. Just typing:
+
+   % make
+   
+in this directory should re-build everything. You'll get a listing,
+some object files, and the ROM image itself.
+
+
+Changes from the EhBASIC 2.22
+-----------------------------
+
+  - Minor syntax changes to allow assembly with the cc65 tool chain.
+
+  - Memory map modified for Symon.
+
+  - At reset, configure the 6551 ACIA for 8-N-1, 2400 baud.
+ 
+  - Monitor routines 'ACIAin' and 'ACIAout' modified for the 6551 ACIA.
+    Specifically, reading and writing will check the 6551 status register for
+    the status of rx and tx registers before receive or transmit.
+
+EhBASIC is copyright Lee Davison <leeedavison@googlemail.com>
+
+My changes are so slight that I hesitate to even say this, but for "CYA"
+reasons:
+
+Changes are copyright Seth Morabito <web@loomcom.com> and are distributed under
+the same license as EhBASIC. I claim no commercial interest whatsoever. Any
+commercial use must be negotiated directly with Lee Davison.
+
+
+Original EhBASIC 2.22 README
+----------------------------
+
+ Enhanced BASIC is a BASIC interpreter for the 6502 family microprocessors. It
+ is constructed to be quick and powerful and easily ported between 6502 systems.
+ It requires few resources to run and includes instructions to facilitate easy
+ low level handling of hardware devices. It also retains most of the powerful
+ high level instructions from similar BASICs.
+
+ EhBASIC is free but not copyright free. For non commercial use there is only one
+ restriction, any derivative work should include, in any binary image distributed,
+ the string "Derived from EhBASIC" and in any distribution that includes human
+ readable files a file that includes the above string in a human readable form
+ e.g. not as a comment in an HTML file.
+
+ For commercial use please contact me,  Lee Davison, at leeedavison@googlemail.com
+ for conditions.
+
+ For more information on EhBASIC, other versions of EhBASIC and other projects
+ please visit my site at ..
+
+	 http://mycorner.no-ip.org/index.html
+
+
+ P.S. c't magazin, henceforth refered to as "those thieving german bastards", are
+ prohibited from using this or any version of EhBASIC for any of their projects
+ or products. The excuse "we don't charge people for it" doesn't wash, it adds
+ value to your product so you owe me.

samples/ehbasic_crtc/min_mon.asm

@@ -0,0 +1,215 @@
+
+; minimal monitor for EhBASIC and 6502 simulator V1.05
+
+; To run EhBASIC on the simulator load and assemble [F7] this file, start the simulator
+; running [F6] then start the code with the RESET [CTRL][SHIFT]R. Just selecting RUN
+; will do nothing, you'll still have to do a reset to run the code.
+
+	.feature labels_without_colons
+	.include "basic.asm"
+
+; put the IRQ and MNI code in RAM so that it can be changed
+
+IRQ_vec	= VEC_SV+2		; IRQ code vector
+NMI_vec	= IRQ_vec+$0A	; NMI code vector
+
+; setup for the 6502 simulator environment
+
+IO_AREA		= $8800
+ACIAdata	= IO_AREA		; simulated ACIA r/w port
+ACIAstatus	= IO_AREA+1
+ACIAcommand	= IO_AREA+2
+ACIAcontrol	= IO_AREA+3
+
+	CRSR_L	= $20B
+
+
+; now the code. all this does is set up the vectors and interrupt code
+; and wait for the user to select [C]old or [W]arm start. nothing else
+; fits in less than 128 bytes
+
+.segment "MONITOR"
+	.org	$FC00			; pretend this is in a 1/8K ROM
+
+; reset vector points here
+
+RES_vec
+	CLD				; clear decimal mode
+	LDX	#$FF			; empty stack
+	TXS				; set the stack
+
+; Initialize the ACIA
+ACIA_init
+	LDA	#$00
+	STA	ACIAstatus		; Soft reset
+	LDA	#$0B
+	STA	ACIAcommand		; Parity disabled, IRQ disabled
+	LDA	#$1E
+	STA	ACIAcontrol		; Set output for 8-N-1 9600
+
+; set up vectors and interrupt code, copy them to page 2
+
+	LDY	#END_CODE-LAB_vec	; set index/count
+LAB_stlp
+	LDA	LAB_vec-1,Y		; get byte from interrupt code
+	STA	VEC_IN-1,Y		; save to RAM
+	DEY				; decrement index/count
+	BNE	LAB_stlp		; loop if more to do
+
+; now do the signon message, Y = $00 here
+
+LAB_signon
+	LDA	LAB_mess,Y		; get byte from sign on message
+	BEQ	LAB_nokey		; exit loop if done
+
+	JSR	V_OUTP		; output character
+	INY				; increment index
+	BNE	LAB_signon		; loop, branch always
+
+LAB_nokey
+	JSR	V_INPT		; call scan input device
+	BCC	LAB_nokey		; loop if no key
+
+	AND	#$DF			; mask xx0x xxxx, ensure upper case
+	CMP	#'W'			; compare with [W]arm start
+	BEQ	LAB_dowarm		; branch if [W]arm start
+
+	CMP	#'C'			; compare with [C]old start
+	BNE	RES_vec		; loop if not [C]old start
+
+	JMP	LAB_COLD		; do EhBASIC cold start
+
+LAB_dowarm
+	JMP	LAB_WARM		; do EhBASIC warm start
+
+
+ACIAout:	
+
+	PHA
+@loop:	LDA	ACIAstatus
+	AND	#$10
+	BEQ	@loop		; Wait for buffer to empty
+	PLA
+	STA	ACIAdata
+	RTS
+
+;;; Byte out to the CRTC
+;;;
+;;; 1. Increment cursor position.
+;;; 2. Scroll if necessary.
+;;; 3. Store new cursor position in CRTC.
+
+	CRSR_L	= $DE		; Cursor address (low)
+	CRSR_H	= $DF		; Cursor address (high)
+	COL_M	= 40		; Max Column
+	ROW_M	= 25		; Max Row
+	CRSR_C	= $E0		; Cursor Column #
+	CRSR_R	= $E1		; Cursor Row #
+
+CRTCout:
+	JSR	ACIAout		; Also echo to terminal for debugging.
+
+	;; 1. Is this an enter (cr/lf)?
+	;;   Set CRSR_C = 0.
+	;;   Increment CRSR_R.
+	;;   If CRSR_R > ROW_M, scroll..
+	CMP	#$0A
+	BEQ	@doenter
+	CMP	#$0D
+	BEQ	@doenter
+	
+	;; 1. Is this a backspace?
+	;;   IF CRSR_C == 0 && CRSR_R == 0
+	;;     Do nothing, already home
+	;;   If CRSR_C > 0
+	;;     Set CRSR_C = CRSR_C - 1
+	;;   Else
+	;;     Set CRSR_C = COL_M
+	;;     Set CRSR_R = CRSR_R - 1
+	;; 
+	CMP	#$08
+	BEQ	@dobs
+
+	;; Otherwise, this is a normal character
+	;; Do normal character stuff.
+	JMP	@done
+
+@doenter:
+@dobs:	
+@done:
+	RTS
+
+;
+; byte in from ACIA. This subroutine will also force
+; all lowercase letters to be uppercase.
+;
+ACIAin
+	LDA	ACIAstatus		; Read 6551 status
+	AND	#$08			;
+	BEQ	LAB_nobyw		; If rx buffer empty, no byte
+
+	LDA	ACIAdata		; Read byte from 6551
+	CMP	#'a'			; Is it < 'a'?
+	BCC	@done			; Yes, we're done
+	CMP	#'{'			; Is it >= '{'?
+	BCS	@done			; Yes, we're done
+	AND	#$5f			; Otherwise, mask to uppercase
+@done
+	SEC				; Flag byte received
+	RTS
+
+LAB_nobyw
+	CLC				; flag no byte received
+no_load				; empty load vector for EhBASIC
+no_save				; empty save vector for EhBASIC
+	RTS
+
+; vector tables
+
+LAB_vec
+	.word	ACIAin		; byte in from simulated ACIA
+	.word	CRTCout		; byte out to simulated ACIA
+	.word	no_load		; null load vector for EhBASIC
+	.word	no_save		; null save vector for EhBASIC
+
+; EhBASIC IRQ support
+
+IRQ_CODE
+	PHA				; save A
+	LDA	IrqBase		; get the IRQ flag byte
+	LSR				; shift the set b7 to b6, and on down ...
+	ORA	IrqBase		; OR the original back in
+	STA	IrqBase		; save the new IRQ flag byte
+	PLA				; restore A
+	RTI
+
+; EhBASIC NMI support
+
+NMI_CODE
+	PHA				; save A
+	LDA	NmiBase		; get the NMI flag byte
+	LSR				; shift the set b7 to b6, and on down ...
+	ORA	NmiBase		; OR the original back in
+	STA	NmiBase		; save the new NMI flag byte
+	PLA				; restore A
+	RTI
+
+END_CODE
+
+; sign on string
+
+LAB_mess
+	.byte	$0D,$0A,"Symon (c) 2008-2014, Seth Morabito"
+	.byte   $0D,$0A,"Enhanced 6502 BASIC 2.22 (c) Lee Davison"
+	.byte   $0D,$0A,"[C]old/[W]arm ?",$00
+
+
+; system vectors
+
+.segment "VECTORS"
+	.org	$FFFA
+
+	.word	NMI_vec		; NMI vector
+	.word	RES_vec		; RESET vector
+	.word	IRQ_vec		; IRQ vector
+

samples/ehbasic_crtc/symon.config

@@ -0,0 +1,18 @@
+MEMORY {
+RAM1: start = $0000, size = $8000;
+ROM1: start = $C000, size = $3C00, fill = yes;
+MONITOR: start = $FC00, size = $3FA, fill = yes;
+ROMV: start = $FFFA, size = $6, file = %O, fill = yes;
+}
+
+SEGMENTS {
+CODE:     load = ROM1, type = ro;
+DATA:     load = ROM1, type = ro;
+MONITOR:  load = MONITOR, type = ro;
+VECTORS:  load = ROMV, type = ro;
+}
+
+SYMBOLS {
+__STACKSIZE__ = $0300;
+}
+

src/main/java/com/loomcom/symon/machines/SymonMachine.java

@@ -53,7 +53,6 @@ public class SymonMachine implements Machine {
 
     // CRTC at $9000-$9001
     private static final int CRTC_BASE = 0x9000;
-    private static final int VIDEO_RAM_BASE = 0x7000;
 
     // 16KB ROM at $C000-$FFFF
     private static final int ROM_BASE = 0xC000;

src/main/java/com/loomcom/symon/ui/VideoWindow.java

@@ -138,7 +138,7 @@ public class VideoWindow extends JFrame implements DeviceChangeListener {
 
         this.scheduler = Executors.newSingleThreadScheduledExecutor();
         this.crtc = crtc;
-        this.charRom = loadCharRom("/pet.rom");
+        this.charRom = loadCharRom("/cga8.rom");
         this.scaleX = scaleX;
         this.scaleY = scaleY;
         this.shouldScale = (scaleX > 1 || scaleY > 1);