This project started so I could self-host a presentation from a Commodore 64 emulator about said emulator.
Example slide definition:
4000 DATA "!-"
4050 DATA "!C
4100 DATA "!F7
4150 DATA ""
4200 DATA "HISTORY"
4250 DATA ""
4300 DATA "!F15"
4350 DATA "!L"
4400 DATA "- * GOAL: MINIMAL IMPLEMENTATION"
4450 DATA ""
4500 DATA "- * PUZZLE: JUST BASIC?
4550 DATA "- * PUZZLE: 6502 EMULATOR
4600 DATA ""
4650 DATA "- * EMULATOR PLAYGROUND"
4700 DATA "- * WHAT IFS"
4750 DATA "!-"
Slides are defined in BASIC DATA statements.
DATA "!B6" : REM background color 6
DATA "!D12" : REM border color 12
DATA "!F3" : REM foreground color 3
DATA "!." : REM horizontal line
DATA "!-" : REM new slide
DATA "!C" : REM center align text
DATA "!L" : REM left align text
DATA "!E" : REM end of slides
DATA "TEXT" : REM display string TEXT using large 4x4 font
DATA "-TEXT" : REM use standard size font
DATA "" : REM blank line
User can use left/right cursor keys to navigate, and number keys to jump to page, advances on other keys
Source code is 6502 assembler and BASIC targeting Commodore 64
Low resolution PETSCII graphics machine language support has five entry points.
SYS 49152,X,Y : REM to plot using the quad-character PETSCII graphics 80x50 on 40x25 screen using POKEs
SYS 49155,X,Y,V-1 : REM plot vertical line V pixels (80x50) high using POKEs
SYS 49158,X,Y,H-1 : REM plot horizontal line H pixels (80x50) wide using POKEs
SYS 49161,"Hello" : REM draw big text (4x4 characters) using lores pixels using character out
SYS 49164,X,Y : REM locate text cursor on 40x25 screen using HOME/LEFT/DOWN characters out
SYS 49167,X,Y : REM draw line to 80x50 position using quad-character PETSCII graphics PEEK/POKEs
SYS 49170,C : REM set plot(1), or unplot(0) for subsequent plot operations
SYS 49173 : REM store text/color to save buffer
SYS 49176 : REM swap text/color with save buffer
Note that the big text entry supports control characters (18/146, 14/142) for reverse on/off and lowercase on/off and a sample program "BIG EDITOR" is included to demonstrate typing big text on the screen with cursor control, colors, etc.
LORES DEMO program
BIG EDITOR program
F1 Help F2 Black on White
F3 Background Color+ F4 Background Color-
F5 Border Color+ F6 Border Color-
F7 White on Black F8 Save to BASIC
Cursor keys, Del, Return, Clear, Home
RVS On/Off
Ctrl+N toggle lowercase/graphics
Ctrl+1-8 CBM+1-8 colors
Building requires bin/win/acme.exe and bin/win/c1541.exe from Vice and revise build.sh to use more Vice executables.
Slides.D64 disk image