initial commit

2026-07-15 21:31:51 +02:00
commit 0fb584bcd7
12 changed files with 1605 additions and 0 deletions
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+; -----------------------------------------------------------
+; defs.asm - hardware registers, constants, zero page, macros
+; included first by main.asm
+; -----------------------------------------------------------
+
+; ---- hardware registers ----
+RASTER  = $d012          ; current raster line
+BORDER  = $d020          ; border color register
+BG      = $d021          ; background color register
+SCREEN  = $0400          ; screen RAM (40x25 chars)
+COLRAM  = $d800          ; color RAM
+SPRPTR  = $07f8          ; sprite pointers (screen RAM + $3f8)
+CIA1_PA = $dc00          ; CIA1 port A: keyboard columns / joystick 2
+CIA1_PB = $dc01          ; CIA1 port B: keyboard matrix row read
+CIA1_TA = $dc04          ; CIA1 timer A low byte: free-running entropy
+
+; ---- sprite registers ----
+SPRPOS   = $d000         ; sprite 0 x; +1 = y, +2 = sprite 1 x, ...
+SPR_MSBX = $d010         ; 9th bit of each sprite's x coordinate
+SPR_EN   = $d015         ; sprite enable bits
+SPR_YEX  = $d017         ; vertical expand
+SPR_PRIO = $d01b         ; 1 = sprite behind the characters
+SPR_MC   = $d01c         ; multicolor enable
+SPR_XEX  = $d01d         ; horizontal expand
+SPR_COL  = $d027         ; sprite 0 color, +1 = sprite 1, ...
+
+
+; ---- colors ----
+BLACK   = 0
+WHITE   = 1
+LGREY   = 15
+
+; ---- joystick port 2 bits (after read_joy, active high) ----
+JOY_LEFT  = 4
+JOY_RIGHT = 8
+JOY_FIRE  = 16
+
+; ---- game constants ----
+LANES     = 5
+NRABBITS  = 7            ; rabbit slots, hardware sprites 1-7
+MAX_MISS  = 3
+ROAD_CX   = 184          ; road center in sprite x coordinates
+PLAYER_SY = 200          ; scooter sprite top (feet on raster line 221)
+T_BIG     = 112          ; rabbit distance where the big frames start
+T_EXP     = 192          ; ... and where the sprite gets double-sized
+REP_HOLD  = 12           ; frames before a held direction auto-repeats
+REP_PERIOD = 6           ; frames between auto-repeat steps
+RAS_SYNC  = 251          ; raster line polled for the frame sync
+
+; ---- zero page pointers (same slots as the c64-demo) ----
+txtlo  = $f5             ; text pointer for the print routines (2 bytes)
+txthi  = $f6
+updvec = $f9             ; state update vector (2 bytes)
+scrlo  = $fb
+scrhi  = $fc
+collo  = $fd
+colhi  = $fe
+
+; ---- helper macros: print a normal / big text line ----
+!macro prtext .row, .col, .color, .txt, .len {
+    lda #<.txt
+    sta txtlo
+    lda #>.txt
+    sta txthi
+    lda #.row
+    sta prow
+    lda #.col
+    sta pcol
+    lda #.color
+    sta pcolor
+    lda #.len
+    sta plen
+    jsr print_text
+}
+
+!macro prbig .row, .col, .color, .txt, .len {
+    lda #<.txt
+    sta txtlo
+    lda #>.txt
+    sta txthi
+    lda #.row
+    sta bigrow
+    lda #.col
+    sta bigcol
+    lda #.color
+    sta bigcolor
+    lda #.len
+    sta biglen
+    jsr draw_big
+}
+
+; ---- set the state update vector ----
+!macro setupd .addr {
+    lda #<.addr
+    sta updvec
+    lda #>.addr
+    sta updvec+1
+}