gbos.git/src/osk.asm, branch master

term: SCY ring-scroll - scroll writes ONE map row; OSK toggle is 212 cycles

2026-07-18T19:50:22Z

The BG map's 32 rows become a ring: logical row L always lives at map row (wMapTop + L) & 31, and SCY = (wMapTop + wViewTop)*8 places the view. Scrolling bumps wMapTop, rebuilds the one new bottom line and writes its single map row (map_row_one); the other 17 rows move for free. The whole OSK view dance - shift the cursor above the keys, restore the backlog on hide - is now term_view_update: one SCY write, no map rewrite at all. OSK safety: the keyboard lives on the WINDOW layer, which SCY never moves. Stale ring rows can only appear under it: wViewTop = max(0, wCurRow-14) <= 3 is nonzero only while the OSK is visible, and the window covers exactly those bottom 3 rows (WX=7, WY=120). Verified: scroll + view shift + scroll-while-OSK-up + backlog restore all pixel-correct via VRAM screenshots; full README demo passes. term_scroll: 78.5k -> 35.6k T-cycles (857k pre-optimization: 24x). OSK toggle: 45k tilemap rewrite -> 212 cycles. Regenerated demo/gbos-demo.gif on the new renderer.

term: 7-color terminal (per-glyph fg+bg) + ANSI escapes; colorize irc

2026-07-18T18:41:27Z

Fano-plane palette scheme: the 7 colors map onto 7 CGB BG palettes so any color pair shares one palette; a tile's palette is picked from the set of colors its two cells need (tables generated by tools/gencolor.py). Per cell a packed (bg<<4)|fg byte lives alongside the char shadow, and the glyph blitter steers glyph/empty pixels to each cell's fg/bg color slots via plane masks. An ANSI-ish CSI parser (ESC [ .. m) drives it; usr/ansi.c demos it and the irc client now renders hashed nick colors, status dimming and a channel-activity bar.

term: dark mode - black background, white text (OSK highlight inverts to match)

2026-07-17T22:31:27Z

term: compute the OSK view offset from the cursor row (keep input visible)

2026-07-16T14:46:21Z

A fixed offset of OSK_ROWS pushed the cursor off the top of the screen when there was little backlog (e.g. a fresh terminal: cursor at logical row 0 -> screen row -3, hidden). Now the offset is max(0, wCurRow - 14): 0 when the cursor is within the visible area, growing only enough to keep the cursor line at the bottom visible row (14) once the terminal has filled past it. compute_offset (from wOskVisible + wCurRow) runs at the top of term_write_tilemap; cursor_down re-runs the tilemap when the cursor changes rows while the OSK is up; osk_toggle just re-runs it. Shared OSK_DOCK constant in gbos.inc keeps term.asm and osk.asm in sync. Verified: fresh terminal + OSK shows the input at row 0; filling past row 14 shifts the view to hold the input at row 14; full screen + OSK puts it at row 14; toggle on+off is still lossless.

term/osk: view-offset scroll region (lossless backlog on OSK toggle)

2026-07-16T14:40:45Z

Replace the shrink-and-scroll region with a view offset. The terminal is always 18 logical rows; term_write_tilemap maps screen row -> logical row + wViewTop (rows the OSK covers clamp to the cursor line). Showing the OSK sets the offset to OSK_ROWS so the cursor line lands at row 14 (above the keyboard) and hiding it sets the offset back to 0 - now purely a remap, so nothing is scrolled off or destroyed. term_set_view replaces term_set_rows; term_scroll/cursor_down are back to plain 18-row scrolling. Result: full 18-row backlog when the OSK is hidden, a shifted 15-row window when shown, and toggling is lossless (verified: OSK-shown view == baseline rows 3..17, and toggle on+off == baseline exactly).

term/osk: scroll region so the OSK never hides the input line

2026-07-16T14:30:33Z

The terminal now has a variable usable height (wTermRows). term_scroll and cursor_down operate within [0 .. wTermRows-1], and term_set_rows(n) shrinks or grows that region, scrolling the cursor up into view when it would fall outside. osk_toggle shrinks the terminal to the rows above the keyboard on show (18 - OSK_ROWS = 15) and restores full height on hide, so the active line is always visible just above the docked keyboard, and hiding the OSK reclaims all 18 rows. Also add c/count.c ("count [n]", default 25): prints n numbered lines to observe/debug scrolling and the scroll-region behavior. Registered as program id 21 / bank 23. Fixed the arg to read argv[0] (getargs returns the string after the command name). Verified: filling the screen then opening the OSK scrolls the latest line to row 14 (visible) with the keyboard at 15-17; closing it restores rows 15-17; count N prints exactly N lines.

osk: bind START to Enter (CR)

2026-07-16T14:19:32Z

START now returns $0A regardless of cursor position, so you can submit a command without navigating to the CR key. The CR key still works too.

sh: handle backspace in readline; prompt is now '#'

2026-07-16T14:17:02Z

readc() returning $08/$7F now drops the last char from the command buffer (and emits one $08 so the terminal erases it) instead of storing the raw byte. Previously "lzs" left the buffer as "lz\x08s", so the command "ls" was reported "not found" even though the screen showed "ls". Also change the shell prompt from '$' to '#'. osk: B button types the selected key SHIFTED (uppercase a-z). A types the key as shown (lowercase/digit/symbol); B on a letter subtracts 32 for the uppercase glyph (the font already has A-Z). Non-letters are unchanged.

osk: wrap the cursor around all four edges

2026-07-16T14:11:06Z

Left at column 0 wraps to the last column (and vice-versa); up at the top row wraps to the bottom (and vice-versa). Makes reaching far keys quicker - e.g. the Enter/space area is one UP away from the top row.

osk: toggle-able on-screen keyboard on the window layer

2026-07-16T14:07:01Z

A joypad-driven keyboard that costs zero permanent screen space: it lives on the GB window layer, so SELECT just flips LCDC bit 5 (window enable) and the terminal's background layer underneath is never disturbed. - src/joypad.asm: read $FF00 with edge detection (wPadCur/Prev/New). - src/osk.asm: 3x20 key grid (letters, digits, space, punctuation, plus Enter/Backspace) built once into spare bank-1 VRAM tiles (104+) and laid out on the $9C00 window map, docked to the bottom 3 rows. The highlighted key is a palette swap on its window attribute byte (CGB BG palette 1 = inverted), so moving the cursor is 1-2 attribute writes with no tile rebuilding. SELECT toggles, d-pad moves, A types. - KGetc's console poll loop now polls the joypad and osk_handle each iteration; a key press returns its byte to the reader exactly like a serial byte, so the shell is oblivious to the input source. Verified in the emulator (via --keys): SELECT shows the keyboard, the highlight tracks the d-pad, and typing "ls"+Enter runs the command and lists the files; a second SELECT hides it and reclaims the full 18 rows. Known limitation: the OSK overlays the bottom 3 terminal rows, so if the prompt has scrolled to the very bottom the current input line can be hidden. A follow-up can add a scroll region (terminal uses rows 0-14 while the OSK is up). Input over serial still works unchanged.