Show HN: I wrote a BASIC interpreter that boots on UEFI machines

# Thoreau BASIC by Tarjan Source: [https://tarjan.itch.io/thoreaubasic](https://tarjan.itch.io/thoreaubasic) ### ***Thoreau BASIC*** A GW\-BASIC–compatible interpreter that runs on bare metal \(a Windows version is available, too\)\. The data segment is sized to the largest block of conventional memory the firmware \(or Windows\) reports, which on a modern machine is gigabytes\. **Language** - \(mostly\) GW\-BASIC compatible\. Programs load and save as ASCII\. - Numeric types, including 32 and 64\-bit integers \(`%`,`&`,`&&`\), single and double precision, strings\. - 32 bit wide line numbers\. - `DEF FN`,`GOSUB`,`ON…GOTO/GOSUB`,`DATA`/`READ`/`RESTORE`, and the rest of the control flow\. - Error trapping:`ON ERROR GOTO`,`RESUME`/`RESUME NEXT`/`RESUME n`,`ERL`,`ERR`,`ON BREAK GOTO` **Graphics** - `PSET`,`LINE`,`CIRCLE`,`PAINT`and friends at native framebuffer resolution\. PSET, LINE and PAINT usable with 16 color EGA or 24 bit R,G,B syntax\. - 16\-color EGA palette*and*24\-bit color:`COLOR r,g,b`\(and a background triple\)\. - Bitmaps:`LOADBMP slot, file$`reads a 24/32\-bpp Windows`\.BMP`into a data\-segment slot;`BITBLT slot, x, y \[,key\]`blits it, with an optional transparent color key for sprites\. - `GRAMAXX`/`GRAMAXY`\(graphics\) and`TXTMAXX`/`TXTMAXY`\(text\) are readable variables holding the actual bounds\. - `SCREEN x,y`requests a mode\.`SCREEN 1024,768`works on almost every machine and is usually the boot mode; try your native resolution for a sharper picture\.`GRAMAXX`/`GRAMAXY`update after a`SCREEN`command\. **Text** - IBM VGA 8×16 font, soft\-scrolling console\. - Multiple text windows:`WINDOW @n, x1,y1,x2,y2`carves a region;`PRINT @n`,`CLS @n`,`LOCATE @n`and`COLOR @n`work inside it, each window with its own cursor and pen/paper\. Plain`PRINT`still owns the whole screen\. **Memory & hardware** - A three\-pointer memory model with no 64KB ceiling\. Arrays in the billions of elements, if you want them\. - `PEEK`,`POKE`,`VARPTR`, and readable pointers into the machine:`LOMEM`,`HIMEM`,`FREEBOT`,`FREETOP`,`SCRNADR`,`GRAPITCH`\. - 64\-bit`HEX$`/`OCT$`\. **Disk I/O**—`SAVE`,`LOAD`,`MERGE`,`FILES`,`KILL`, running directly on the UEFI Simple File System\. **Editing**— full\-screen`EDIT`,`AUTO`line numbering, and`RENUM`\(renumbers and rewrites every`GOTO`/`GOSUB`/`THEN`/`ELSE`/`ON…`/`RESTORE`/`RESUME`/`ERL`reference\)\. **Timing**— the`TIMER`variable reads a high\-precision clock from the CPU's invariant TSC\. **New in v1\.2** - CHDIR, MKDIR, RMDIR, FIELD, GET\#, PUT\#, LSET, RSET - CVI, CVS, CVD, MKI$, MKS$, MKD$ - TAB\(\), SPC\(\) - OPTION BASE, ERASE - NAME old$ AS new$ - MERGE - DELETE - CSGN, CDBL - ERROR n, TRON, TROFF - SCREEN \(\) function **New in v1\.1\.3** - MID$ can be an assignment now - ERL wasn't stored and no error line was shown when a program exited with an error - INPUT: backspace didn't work right **New in v1\.1\.2** - When available RAM was less than 4 GB, the Windows version bailed out\. - BASIC lines are now fixed to 244 characters without line numbers\. - EDIT/LIST bug: when line number was greater 32767 it showed an empty line 0 instead\. **New in v1\.1\.1** - Bare metal: Fixed the slow scrolling and writing to the framebuffer\. - Win**d**ows: Added autostart\. You may now call ThorauBASIC with a \.bas filename attached, it will autostart\. **New in v1\.1** - **Much faster\.**A per\-line token cache, a precedence\-climbing expression evaluator, and variable\-slot caching \. Roughly 25× quicker on compute\-heavy programs\. The bundled Mandelbrot dropped from ~230s to under 10s, and Conway's Life now runs interactively\. Lunar Lander runs at a fixed 100 fps now\. - Bitmaps \(`LOADBMP`/`BITBLT`\), text windows with per\-window color,`ON ERROR`/`ON BREAK`/`RESUME`,`ERL`/`ERR`,`RENUM`, and`PEEK`/`POKE`/`VARPTR`\. - Correctness fixes: exact 64\-bit integer math \(overflow promotes to double\), cleaner number formatting, and full\-width`HEX$`\. ## Download Click download now to get access to the following files: ## Development log - [v 1\.2 \- CHDIR, MKDIR, RMDIR and more](https://tarjan.itch.io/thoreaubasic/devlog/1639533/v-12-chdir-mkdir-rmdir-and-more)11 hours ago - [v 1\.1\.3 \- MID$, ERL and INPUT bugs](https://tarjan.itch.io/thoreaubasic/devlog/1638308/v-113-mid-erl-and-input-bugs)1 day ago - [v1\.1\.2 \-](https://tarjan.itch.io/thoreaubasic/devlog/1638164/v112-)1 day ago - [v1\.1\.1 \- Autostart for Windows and scrolling fix for bare metal](https://tarjan.itch.io/thoreaubasic/devlog/1637903/v111-autostart-for-windows-and-scrolling-fix-for-bare-metal)1 day ago - [Windows version is here\!](https://tarjan.itch.io/thoreaubasic/devlog/1637465/windows-version-is-here)2 days ago - [v1\.1 — 25× faster, plus added features](https://tarjan.itch.io/thoreaubasic/devlog/1636874/v11-25-faster-plus-added-features)2 days ago - [v1\.0 milestone](https://tarjan.itch.io/thoreaubasic/devlog/1630056/v10-milestone)9 days ago - [TIMER is now high precision](https://tarjan.itch.io/thoreaubasic/devlog/1621566/timer-is-now-high-precision)16 days ago [View all posts](https://tarjan.itch.io/thoreaubasic/devlog)