Replaces individual malloc/free string management with a contiguous pool
(default 32KB) and compacting GC, matching the original GW-BASIC's
GETSPA/GARBAG architecture. Allocation is a bump pointer; gw_str_free()
is a no-op (descriptors are nulled, data reclaimed by GC). Compaction
runs at statement boundaries when the pool drops below 4KB free, walking
the variable table and array storage to relocate live strings.
FRE() now returns actual free pool space. FRE("") triggers a GC pass
before reporting. CLEAR n sets the string space size.
Closes the last unimplemented extended statement tokens. ENVIRON uses
putenv/getenv for real environment variable access. DATE$/TIME$
assignment is accepted but silently ignored (no system clock modification).
ERDEV/ERDEV$/IOCTL$/PEN return stub values (no real device hardware).
CALL/CALLS raise Illegal function call. COM event trapping silently
accepted.
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.
