8bitlenser/lenser/c16/viewer/viewer.s
2026-07-03 19:35:35 -07:00

26 lines
965 B
ArmAsm

; Commodore 16 (TED 7360/8360) hires bitmap viewer.
;
; The whole picture is already laid out in RAM by the PRG (loaded via quickload):
; $1800 attribute matrix (luminance) 1000 bytes
; $1C00 colour matrix (hue) 1000 bytes
; $2000 bitmap 8000 bytes
; This just programs the TED for 320x200 hires bitmap mode and holds the display.
* = $1020
start:
sei
lda #$08
sta $ff12 ; bitmap base = $2000
lda #$18
sta $ff14 ; video matrix base = $1800 (hue matrix at $1C00)
lda #$00
sta $ff15 ; background colour (per-cell in hires; black)
lda #$00
sta $ff19 ; border / frame colour = black
lda #$08
sta $ff07 ; MCM off (hires), 40 columns
lda #$3b
sta $ff06 ; bitmap mode on, display on, 25 rows (set last)
loop:
jmp loop