New SplitBit programs.

2026-08-13 23:42:55 -04:00
parent c2440ae5fa
commit 94b3a7af28
15 changed files with 1155 additions and 0 deletions
@@ -0,0 +1,326 @@
+; Conway's Game of Life for SplitBit.
+;
+; The visible field is 16x16, surrounded by a permanently dead one-cell border.
+; Each of the 18x18 allocated cells is stored as two adjacent bytes:
+;   current state, next state
+; This makes double buffering possible with SplitBit's single Data Pointer.
+;
+; The initial pattern is a glider. ANSI terminal control codes redraw the field
+; in place. Press Ctrl-C to stop the emulator.
+
+#Include Libraries/print.asm
+
+#Program
+
+start:
+  CALL seedGlider
+  SETD ClearScreen
+  CALL printString
+
+generationLoop:
+  CALL renderBoard
+  CALL evolveBoard
+  CALL commitBoard
+  CALL frameDelay
+  BRI generationLoop
+
+seedGlider:
+  ; Coordinates in the padded field:
+  ;   .#.
+  ;   ..#
+  ;   ###
+  SETD Board
+  DPUP 0d42
+  INIA 0x01
+  STA
+  SETD Board
+  DPUP 0d80
+  STA
+  SETD Board
+  DPUP 0d112
+  STA
+  SETD Board
+  DPUP 0d114
+  STA
+  SETD Board
+  DPUP 0d116
+  STA
+  RET
+
+renderBoard:
+  SETD CursorHome
+  CALL printString
+  SETD Board
+  DPUP 0d38
+  INIA 0d16
+  SETD RowCount
+  STA
+  SETD Board
+  DPUP 0d38
+
+renderRow:
+  PSHD
+  INIA 0d16
+  SETD ColCount
+  STA
+  POPD
+
+renderCell:
+  LDA
+  BRA renderDead
+  INIB 0x23
+  OUTB 0x00
+  BRI renderCellDone
+renderDead:
+  INIB 0x20
+  OUTB 0x00
+renderCellDone:
+  DPUP 0d02
+  PSHD
+  SETD ColCount
+  LDA
+  DECA
+  STA
+  BRA renderRowDone
+  POPD
+  BRI renderCell
+
+renderRowDone:
+  POPD
+  CALL lineFeed
+  DPUP 0d04
+  PSHD
+  SETD RowCount
+  LDA
+  DECA
+  STA
+  BRA renderDone
+  POPD
+  BRI renderRow
+
+renderDone:
+  POPD
+  RET
+
+evolveBoard:
+  SETD Board
+  DPUP 0d38
+  INIA 0d16
+  SETD RowCount
+  STA
+  SETD Board
+  DPUP 0d38
+
+evolveRow:
+  PSHD
+  INIA 0d16
+  SETD ColCount
+  STA
+  POPD
+
+evolveCellLoop:
+  CALL evolveCell
+  DPUP 0d02
+  PSHD
+  SETD ColCount
+  LDA
+  DECA
+  STA
+  BRA evolveRowDone
+  POPD
+  BRI evolveCellLoop
+
+evolveRowDone:
+  POPD
+  DPUP 0d04
+  PSHD
+  SETD RowCount
+  LDA
+  DECA
+  STA
+  BRA evolveDone
+  POPD
+  BRI evolveRow
+
+evolveDone:
+  POPD
+  RET
+
+; DP points to the current-state byte of a visible cell.
+evolveCell:
+  CALL countNeighbors
+  PSHQ
+  LDA
+  POPB
+
+  ; Three neighbors always produces a live cell.
+  INIA 0d03
+  CCF
+  SUB
+  BRQ makeAlive
+
+  ; Two neighbors preserve the current state.
+  INIA 0d02
+  CCF
+  SUB
+  BRQ preserveCell
+
+makeDead:
+  RSTA
+  INCD
+  STA
+  DECD
+  RET
+
+preserveCell:
+  LDA
+  BRA makeDead
+
+makeAlive:
+  INIA 0x01
+  INCD
+  STA
+  DECD
+  RET
+
+; Return the sum of the eight neighboring current-state bytes in Q.
+; With interleaved cells and an 18-cell row, the relative offsets are:
+; -38, -36, -34, -2, +2, +34, +36, +38.
+countNeighbors:
+  RSTA
+  DPDN 0d38
+
+  LDB
+  CCF
+  ADD
+  PSHQ
+  POPA
+  DPUP 0d02
+
+  LDB
+  CCF
+  ADD
+  PSHQ
+  POPA
+  DPUP 0d02
+
+  LDB
+  CCF
+  ADD
+  PSHQ
+  POPA
+  DPUP 0d32
+
+  LDB
+  CCF
+  ADD
+  PSHQ
+  POPA
+  DPUP 0d04
+
+  LDB
+  CCF
+  ADD
+  PSHQ
+  POPA
+  DPUP 0d32
+
+  LDB
+  CCF
+  ADD
+  PSHQ
+  POPA
+  DPUP 0d02
+
+  LDB
+  CCF
+  ADD
+  PSHQ
+  POPA
+  DPUP 0d02
+
+  LDB
+  CCF
+  ADD
+  RET
+
+; Copy every next-state byte to its adjacent current-state byte.
+; The border's next bytes remain zero, so it stays permanently dead.
+commitBoard:
+  SETD Board
+  INIA 0d18
+  SETD RowCount
+  STA
+  SETD Board
+
+commitRow:
+  PSHD
+  INIA 0d18
+  SETD ColCount
+  STA
+  POPD
+
+commitCell:
+  INCD
+  LDA
+  DECD
+  STA
+  DPUP 0d02
+  PSHD
+  SETD ColCount
+  LDA
+  DECA
+  STA
+  BRA commitRowDone
+  POPD
+  BRI commitCell
+
+commitRowDone:
+  POPD
+  PSHD
+  SETD RowCount
+  LDA
+  DECA
+  STA
+  BRA commitDone
+  POPD
+  BRI commitRow
+
+commitDone:
+  POPD
+  RET
+
+; Approximately 0.2 seconds at the emulator's nominal 1 MHz rate.
+frameDelay:
+  INIA 0xFF
+delayOuter:
+  INIB 0xFF
+delayInner:
+  DECB
+  BRB delayInnerDone
+  BRI delayInner
+delayInnerDone:
+  DECA
+  BRA delayDone
+  BRI delayOuter
+delayDone:
+  RET
+
+#Data
+
+RowCount:
+  0x00
+ColCount:
+  0x00
+
+ClearScreen:
+  0x1B
+  "[2J"
+CursorHome:
+  0x1B
+  "[H"
+
+; The emulator zero-fills the remainder of Data Memory. Board names the first
+; byte of a 648-byte logical allocation (18 * 18 * 2).
+Board:
+  0x00