dual version: prg + cartridge (8k)

Makefile

@@ -3,10 +3,16 @@
 ASM=$(wildcard src/*.asm)
 RES=res.bin/amour.sid res.bin/levels.bin
 
+ifeq "$(CARTRIDGE)" "1"
+	FORMAT:=3
+else
+	FORMAT:=1
+endif
+
 .PHONY: debug env clean
 
-bin/snake.prg: env $(ASM) $(RES)
+bin/snake.prg: env $(ASM) $(RES) bin/explodefont
-	dasm src/main.asm -Isrc/ -DSYSTEM=64 -DDEBUG=0 -sbuild/symbols.txt -obin/snake.prg
+	dasm src/main.asm -Isrc/ -DSYSTEM=64 -DDEBUG=$(DEBUG) -DVERBOSE=$(VERBOSE) -DCARTRIDGE=$(CARTRIDGE) -f$(FORMAT) -sbuild/symbols.txt -obin/snake.prg
 
 clean:
 	rm -rf {build,bin,res.bin}
@@ -14,9 +20,8 @@ clean:
 env:
 	mkdir -p {build,bin,res.bin}
 
-debug: env $(ASM) $(RES)
+bin/explodefont: util/explodefont.cpp
 	g++ -o bin/explodefont util/explodefont.cpp
-	dasm src/main.asm -Isrc/ -DSYSTEM=64 -DDEBUG=1 -sbuild/symbols.txt -obin/snake.prg
 
 res.bin/amour.sid:
 	cp res.org/amour.sid res.bin/amour.sid

README.md

@@ -13,10 +13,13 @@ You need the GNU compiler collection and the [dasm](https://dasm-assembler.githu
 ```
 $ make
 ```
-You can also make it output useful extra info with:
+You can also define the following environment variables:
-```
+
-$ make debug
+```$ DEBUG=1 make```        build with debugging artifacts
-```
+
+```$ VERBOSE=1 make```      output useful info during compilation
+
+```$ CARTRIDGE=1 make```    produces an 8K bin ready to be burnt to an *PROM
 
 ## Developer docs
 ### Memory map
@@ -25,10 +28,10 @@ Address               | PRG   | Description
 ```$0000 - $0001```   | no    | hardware
 ```$0002 - $00FF```   | no    | zero page pointers
 ```$0100 - $07FF```   | no    | *free ram*
-```$0800 - $0FFF```   | yes   | initialized data segment (incl. const) + BASIC autostart
+```$0800 - $0FFF```   | yes   | autostart (BASIC or cartridge) + Low Program Segment
-```$1000 - $1FFF```   | yes   | SID tune
+```$1000 - $1FFF```   | yes   | SID tune + Middle Program Segment
 ```$2000 - $27FF```   | yes   | custom char
-```$2800 - $xxxx```   | yes   | program logic (only needed part used)
+```$2800 - $xxxx```   | yes   | High Program Segment (only needed part used)
 ```$xxxx - $CCFF```   | no    | *free ram*
 ```$CD00 - $CDFF```   | no    | data segment (not-initialized vars)
 ```$CE00 - $CEFF```   | no    | list X
@@ -36,6 +39,8 @@ Address               | PRG   | Description
 ```$D000 - $DFFF```   | no    | I/O
 ```$E000 - $FFFF```   | no    | Kernal
 
+Note: program (code) segments have been put in all possible free spots in order to squeeze the game into an 8K cartridge.
+
 ### Custom charset
 Index           | Description
 ----------------|-------------
@@ -45,3 +50,8 @@ Index           | Description
 ```$50 - $5F``` |   hex digits, reversed
 ```$60 -    ``` |   game tiles
 
+### Cartridge
+Cartridge version is at $8000 and simply copies itself back at $800.
+
+Cartridge version can not be built with DEBUG=1 flag due to size constraints.
+

src/basic.asm

@@ -1,2 +1,17 @@
-	; 10 SYS10240 ($2800) BASIC autostart
+#if VERBOSE = 1
-    BYTE #$0b,#$08,#$0a,#$00,#$9e,#$31,#$30,#$32,#$34,#$30,#$00,#$00,#$00
+LASTINIT SET .
+#endif
+
+    ; this is at $801
+    ; and it MUST be exactly at this location in order to autostart
+	; 10 SYS2060 ($80c) BASIC autostart
+    BYTE #$0b,#$08,#$0a,#$00,#$9e,#$32,#$30,#$36,#$31,#$00,#$00,#$00
+
+    ; this is at (2061 dec)=($80d)
+    ; and it MUST be exactly after the above BASIC statement
+. = $80d
+    jmp start
+
+#if VERBOSE = 1
+    ECHO "basic.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/cart.asm

@@ -0,0 +1,47 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
+cartridge SUBROUTINE
+
+    WORD #$8009
+    WORD #$801a
+
+    ; CBM80 in PETSCII (cartridge signature for autostart)
+    BYTE #$c3,#$c2,#$cd,#$38,#$30
+
+.coldstart:
+    sei
+    stx $d016
+    jsr $fda3
+    jsr $fd50
+    jsr $fd15
+    jsr $ff5b
+    cli
+
+.warmstart:
+    ; Copy cartridge content into proper memory location
+    ldx #$20
+    lda #$0
+    tay
+    sta srcPointer
+    sta dstPointer
+    lda #>cartridgeStart
+    sta srcPointer + 1
+    lda #$08
+    sta dstPointer + 1
+.loop:
+    lda (srcPointer),y
+    sta (dstPointer),y
+    iny
+    bne .loop
+    inc srcPointer + 1
+    inc dstPointer + 1
+    dex
+    bne .loop
+
+    jmp start
+
+#if VERBOSE = 1
+    ECHO "cart.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/data.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 ; Data section - Not initialized variables ($CD00 - $CDFF)
 ; ----------------------------------------------------------------------
 ; Number of interrupt
@@ -50,3 +54,6 @@ delayStatus:
 score:
     WORD
 
+#if VERBOSE = 1
+    ECHO "data.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/game.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 statusPlay:     ; do Game
     ; Check counter
     ldx irqn
@@ -334,4 +338,6 @@ skipPauseTests:
 
     rts
 
-
+#if VERBOSE = 1
+    ECHO "game.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/gameover.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 ; Game is over
 ; ----------------------------------------------------------------------
 gameover:
@@ -21,4 +25,6 @@ gameover:
     sta status
     rts
 
-
+#if VERBOSE = 1
+    ECHO "gameover.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/initdata.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 ; Initialized variables
 ; ----------------------------------------------------------------------
 
@@ -95,3 +99,6 @@ noMoreLevelsString:
 levelsList:
     INCBIN "../res.bin/levels.bin"
 
+#if VERBOSE = 1
+    ECHO "initdata.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/intro1.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 ; Currently statusIntro0 is the same as statusIntro1
 ; statusIntro1 has just been reserved for future use
 statusIntro0:
@@ -77,4 +81,6 @@ status1okset:
     ; For now, just return.
     rts
 
-
+#if VERBOSE = 1
+    ECHO "intro1.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/introreset.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 ; Intro reset
 ; ----------------------------------------------------------------------
 introreset:
@@ -44,4 +48,6 @@ introresetColorShade
 
     rts
 
-
+#if VERBOSE = 1
+    ECHO "introreset.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/levelreset.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 ; Reset variables for a new level
 ; ----------------------------------------------------------------------
 levelresetvar:
@@ -32,3 +36,6 @@ clearListLoop:
 
     rts
 
+#if VERBOSE = 1
+    ECHO "levelreset.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/levels.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 ; load new level on the screen
 statusLevelTitle SUBROUTINE
     jsr clearScreen
@@ -162,3 +166,6 @@ writeLevelEnd:
     sta status
     rts
 
+#if VERBOSE = 1
+    ECHO "levels.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/main.asm

@@ -15,21 +15,38 @@
     org $02
     INCLUDE "zeropage.asm"
 
-#if DEBUG = 1
+#if VERBOSE = 1
     ; Locations $90-$FF in zeropage are used by kernal
     ECHO "End of zeropage variables. Space left: ",($90 - .)
 #endif
 
 ; Initialized segments
 ; ----------------------------------------------------------------------
-    SEG constSegment
+    SEG autostartSegment
+#if CARTRIDGE = 0
     org $801
-    INCLUDE "basic.asm" ; BASIC must stay at this address
+    INCLUDE "basic.asm" ; BASIC _MUST_ stay at this address
-    INCLUDE "initdata.asm"
+#else
-#if DEBUG = 1
+    org $800
-    ECHO "End of Initialized Data (const) + Basic Segment. Space left: ",($1000 - .)
+    INCLUDE "cart.asm"
 #endif
+    INCLUDE "initdata.asm"
 
+; Program "Segment" Low
+; ----------------------------------------------------------------------
+; You just have to fill this empty space, don't you think so? ;-)
+    INCLUDE "game.asm"
+    INCLUDE "gameover.asm"
+    INCLUDE "introreset.asm"
+    INCLUDE "program.asm"
+    INCLUDE "subroutines.asm"
+    INCLUDE "levels.asm"
+    INCLUDE "intro1.asm"
+; Note: some code had to be included at an higher address
+
+#if VERBOSE = 1
+    ECHO "End of Low Program Segment. Space left:",($1000 - .)
+#endif
 
 ; SID tune (previously properly cleaned, see HVSC)
 ; ----------------------------------------------------------------------
@@ -37,8 +54,14 @@
     org $1000
 sidtune:
     INCBIN "../res.bin/amour.sid"
-#if DEBUG = 1
+#if VERBOSE = 1
-    ECHO "End of SIDtune. Space left: ",($2000 - .)
+    ECHO "End of SIDtune at ",.
+#endif
+    INCLUDE "multicolor.asm"
+    INCLUDE "levelreset.asm"
+    INCLUDE "outro.asm"
+#if VERBOSE = 1
+    ECHO "End of Middle Program Segment. Space left:",($2000 - .)
 #endif
 
 ; Font Data
@@ -49,40 +72,36 @@ sidtune:
 tggsFont:
     INCLUDE "tggs.asm"
 
-; Include program
+; Program Segment High
 ; ----------------------------------------------------------------------
-    SEG programSegment
-    org $2800
-    jmp start
 
-    INCLUDE "game.asm"
+#if VERBOSE = 1
-    INCLUDE "gameover.asm"
+    ECHO "End of High Program Segment at: ",.,"Space left:",($cd00 - .)
-    INCLUDE "levelreset.asm"
-    INCLUDE "introreset.asm"
-    INCLUDE "intro1.asm"
-    INCLUDE "multicolor.asm"
-    INCLUDE "outro.asm"
-    INCLUDE "program.asm"
-    INCLUDE "subroutines.asm"
-    INCLUDE "levels.asm"
-
-#if DEBUG = 1
-    ECHO "End of program at: ",.,"Space left:",($cd00 - .)
 #endif
 
-#if DEBUG = 1
+#if VERBOSE = 1
+#if CARTRIDGE = 0
     ; +2 because of PRG header
     ECHO "PRG size:",([. - $801 + 2]d),"dec"
+#else
+    ECHO "BIN size:",([. - $800]d),"dec"
+#endif
 #endif
 
 ; Uninitialized segments
 ; ----------------------------------------------------------------------
+; Cartridge locations
+; -------------------
+    SEG.U cartridgeSegment
+    org $8000
+cartridgeStart:
+
 ; Data variables
 ; -----------------
     SEG.U dataSegment
     org $cd00
     INCLUDE "data.asm"
-# if DEBUG = 1
+#if VERBOSE = 1
     ECHO "End of Data segment. Space left:",($ce00 - .)
 #endif
 

src/multicolor.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 		processor 6502
 
 multicolor SUBROUTINE
@@ -39,3 +43,7 @@ multicolorOff:
 	and #$ef
 	sta $d016
 	rts
+
+#if VERBOSE = 1
+    ECHO "multicolor.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/outro.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 ; Wait for some delay
 statusDelay SUBROUTINE
     ldy delay           ; load outroDelay and decrement
@@ -11,3 +15,6 @@ statusDelay SUBROUTINE
     sta status
     rts
 
+#if VERBOSE = 1
+    ECHO "outro.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/program.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 ; ENTRY OF PROGRAM
 ; ----------------------------------------------------------------------
 start:
@@ -186,4 +190,6 @@ checkEndStatus:
     ; Go to original system routine
     jmp $ea31
 
-
+#if VERBOSE = 1
+    ECHO "program.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/subroutines.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 ; Subroutines
 ; ----------------------------------------------------------------------
 
@@ -161,3 +165,6 @@ nextPointer:
 
     rts
 
+#if VERBOSE = 1
+    ECHO "subroutines.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/tggs.asm

@@ -1,3 +1,7 @@
+#if VERBOSE = 1
+LASTINIT SET .
+#endif
+
 ; char 0x0, 0
    BYTE #%00000000
    BYTE #%00000000
@@ -2558,3 +2562,7 @@
    BYTE #%11100001
    BYTE #%01010101
    BYTE #%00000000
+
+#if VERBOSE = 1
+    ECHO "tggs.asm @ ",LASTINIT,"len:",(. - LASTINIT)
+#endif

src/zeropage.asm

@@ -22,6 +22,10 @@ nextPointerPointer DS 2
 ; Pointer to string for strlen routine
 strlenString DS 2
 
+; Generic src/dst copy pointers
+srcPointer DS 2
+dstPointer DS 2
+
 ; Note: Locations $90-$FF in zeropage are used by kernal