New portio.c module following the virmem.c dispatch-by-address pattern,
emulating 8253 PIT channel 2 (speaker frequency), PPI port B (speaker
on/off), CGA mode/color select registers, game port (joystick stub),
COM1 serial (transmitter-ready stub), and floating bus default (0xFF).
OUT/WAIT/MOTOR statements and INP()/STICK()/STRIG() functions now fully
functional. Continuous tone generation via PulseAudio pthread worker for
programs that drive the speaker through OUT &H43/&H42/&H61.
Rewrites gfx_draw() as a recursive draw_engine() to support all DRAW
mini-language features:
Bug fixes:
- M command parsing: skip generic arg parser so M100,50 correctly
parses both coordinates instead of consuming x as a generic arg
- S (scale) semantics: distance is now (arg ?: 1) * scale / 4, matching
original GW-BASIC where S4 means 1 pixel per unit, not 4
- A (rotation): implements 90-degree rotation state with direction
vector transform for all 8 direction commands
New features:
- TA n: arbitrary rotation angle (-360 to 360 degrees) via cos/sin
- =variable;: numeric variable substitution in DRAW strings
- X stringvar;: execute substring from string variable (recursive)
- Scale factor applied to relative M coordinates
Binary tokenized SAVE/LOAD now stores float constants in Microsoft Binary
Format (MBF) on disk, matching original GWBASIC.EXE. A token-walking function
(convert_floats) converts IEEE↔MBF at the save_binary()/load_binary() boundary.
Also fixes a latent bug where load_binary() scanned for 0x00 to find the end
of each token line — this fails when float bytes contain null (e.g. MBF for
100.5 is 00 00 49 87). The loader now uses the next-line pointer to compute
token data length, matching the original's approach.
Apply coordinate mapping (VIEW/WINDOW) to POINT(x,y) function so it
returns correct pixel values when WINDOW is active. Remove unused
palette[] array from graphics.c (Sixel encoder uses palette_map[]
directly). Expand view_window.bas test to cover WINDOW SCREEN mode,
VIEW+WINDOW combination, and PMAP inverse mapping. Fix CI test count
in docs.
BSAVE/BLOAD: save and load virtual memory blocks with 0xFD-header
binary format, operating on the current DEF SEG segment.
TUI color: tui_refresh emits ANSI SGR codes from cell attributes;
COLOR statement sets tui.current_attr when TUI is active.
Extended PEEK/POKE: CGA graphics framebuffer (interlaced layout) via
gfx_cga_peek/poke routed through virmem when gfx_active(); BIOS
keyboard shift flags (offset 0x17 bit 7 = insert mode).
Add bibliography to language reference. 64 tests, all passing.
Binary SAVE/LOAD: SAVE now writes tokenized binary by default (0xFF header
format), matching original GW-BASIC behavior. SAVE "file",A for ASCII.
LOAD auto-detects binary vs ASCII from the first byte. Command-line file
loading also auto-detects, so binary .BAS files just work.
INKEY$ extended keys: arrow keys, Home/End/PgUp/PgDn, Insert/Delete, and
F1-F10 now return the correct CHR$(0) + scan_code two-byte sequences per
the IBM PC convention. Refactored event trap key parsing to use tui_read_key()
instead of duplicating escape sequence parsing.
Golden-file regression tests: generated .expected output files for 55 of 58
test programs (3 timing-dependent tests excluded). The test runner now
reports compat match status alongside pass/fail.
Classic programs: added Hamurabi, Lunar Lander, Gunner, and Diamond from
David Ahl's BASIC Computer Games (1978) in tests/classic/ for manual
compatibility testing.
Docs updated with compiler roadmap item and hardware I/O simulator plan.
Eremey Valetov