Welcome

Welcome to my homepage, I'm Óscar Toledo G., and here you'll find my winning entries from contests like the IOCCC, the JS1K and the MSXdev, information about my games for retro consoles, my store of e-books, and also the world's smallest chess programs written by me in C, Java, Javascript and x86/6502 machine code.

If you're looking for information about the Mexican scientist Oscar Toledo Esteva, then please go to the History page of the Familia Toledo organization site.

Update (Feb/12/2026)

My work-in-progress CVBasic v0.9.2 now supports MSX2. PALETTE support added, MODE 4 for extended sprites (8 sprites in line), and DEFINE SPRITE COLOR for setting the sprites' colors. Also added support for the Colecovision Steering Wheel and Roller Controller using CONT1.SPINNER and CONT2.SPINNER. You can test this bleeding-edge version by compiling from the git.
Do you remember my ports of Akalabeth? Now I've made Akalabeth for Colecovision.
Wow! 17 years online!

Update (Dec/23/2025)

You can now buy Las Vegas Solitaire for Intellivision from my digital store.
My new Halloween game for Intellivision is Pumpkin Taxi, available now for download, and also collected as physical edition in Pumpkin Trilogy 2.
I've coded 9 games for my ECS Extended BASIC, also a full screen editor, and made a booklet Reference manual for my ECS Extended BASIC.
MAME now has a patch allowing it to run my ECS Extended BASIC.
I had a table at the Retrogame Fest 4 this Dec/20/2025, many people bought my books. Thank you all!
Happy holidays!

Update (Oct/12/2025)

I've continued working on my extended BASIC interpreter for the Mattel Intellivision ECS. It now supports mathematical functions, text strings, more graphics, cassette support, printer support, and more!
I've added scans for the Mexican manual of Sea Battle (Batalla Naval) for Intellivision.

Update (Sep/28/2025)

I've coded a brand new extended BASIC interpreter for the Mattel Intellivision ECS.
I'm the Champion Coder in the Retrogamer magazine issue 277.
I've added my CP/M Z80 emulator to the archives of my transputer operating system.
The MSX Mexico Meeting 2025 will happen in Oct/25/2025 from 10am to 5pm, at Tata Vasco 31, Coyoacán, CDMX. Enjoy retro exhibitions, buying and sell, and talks!

Update (Aug/28/2025)

I just released CVBasic v0.9.0 with support for NES/Famicom! That's right! Now you can make games for NES/Famicom in 32K, 256K, or 512k sizes. Also many corrections and enhancements, like smaller and faster TI-99/4A code, and support for PNG images in TMSColor.

Update (Aug/14/2025)

I've ported my transputer assembler to MS-DOS, and now the toolchain in MS-DOS is complete with Pascal compiler, assembler, and utilities. Available in my git.

Update (Jul/03/2025)

IntyBASIC v1.5.1 now has been released. INCLUDE usage now is unlimited and can be nested, support for PNG files in IntyColor, and improvements in parsing.
At the end of April 2025, I bought two transputer boards from eBay, I built an ISA board to test both, and I got carried away and made a PCB board compatible with the original Inmos B004 board.
Sydney Hunter and the Caverns of Death for Sega Master System is now available in physical format.
Whack 'Em Smack 'Em Post-Mort'Em! Or how a Sega Master System game was coded with CVBasic.
Now there is a web-based development environment for CVBasic, developed by haroldoop. You can enter your CVBasic programs, compile, and run immediately in your web browser!
Pipe Dreams is a new game for Colecovision coded with CVBasic.

Update (May/07/2025)

CVBasic v0.8.0 adds official support for Sega Master System!
IntyBASIC v1.5.0 now released!
My transputer emulator in Javascript made it to Hackaday!
A letter to my future self.

Update (Apr/02/2025)

Now you can test my transputer operating system in your web browser, because I've ported it to Javascript.

Update (Mar/12/2025)

Ray traced robot made in transputer using my C compiler

Final article of the three-article series about my early years, my full transputer operating system with K&R C compiler. The complete history about how I evolved my operating system to support multiple drives, subdirectories, CD-ROM, along its utilities, plus expanding the compiler. Enjoy it!

Update (Feb/24/2025)

New in my series of articles about my early years, bootstrapping Small-C for transputer and coding an operating system from zero. The history about how I ported the Small-C compiler to transputer, and I had an idea that changed completely my objective.

Update (Feb/04/2025)

New in my series of articles about my early years, my Pascal compiler for transputer.
Routines for pixel drawing, line drawing, and circles for CVBasic.
16 years of this site!

Update (Jan/13/2025)

Unlucky Pony my 2021 game for Intellivision is now freely available in ROM format.
Manhole for Colecovision, is a new game by Eric Damain written in CVBasic.
My CVBasic compiler now has VDP.STATUS and the statements SELECT CASE/END SELECT. I also updated IntyBASIC with these statements plus bank switching support.
The 2nd MSX Mexico Meeting was covered by local TV Channel 34 in a brief capsule, plus a radio program about where I talk about MSX games.
La Cueva Retro recorded my talk about the japanese MSX computers in 2023 (Spanish).

Update (Nov/02/2024)

Pumpkin Bakery is my new Halloween game for Intellivision. You are Pumpkin Smith, the proud owner of a pumpkin pie bakery, and your best customers are... skeletons.
CVBasic v0.7.1 now supports the NABU PC, making it to twelve platforms supported!
Castlevania for Colecovision demo is being developed by Matthew Kiehl using CVBasic.
I've developed a Sound Effect editor for SN76489 and AY-3-8910 in CVBasic, so now you can develop sound effects for all twelve supported platforms.
My assembler gasm80 now supports the undocumented Z80 and 6502 instructions.
I gave a talk about programming games for MSX at the Amerike University on Oct/14/2024, and later on Oct/26/2024 at the MSX Retrocomputing Meet Mexico 2024 at the Torre Axa. The game being developed was Brinquitos.
Akalabeth for Intellivision was available at the PRGE 2024 published by Atariage. Forty copies were sold in less than an hour. It will be available at the Atariage store soon.

Update (Sep/07/2024)

Akalabeth for Intellivision by yours truly will be published by Atariage. It has the rare distinction of being the the first Intellivision game published by Atariage.
CVBasic v0.7.0 adds official support for Tatung Einstein, Casio PV-2000, Hanimex/Soundic Pencil II, and TI-99/4A! The TMS9900 support is courtesy of Mike Brent (tursi).
I've ported GORILLA.BAS to Colecovision using CVBasic, you can download the complete source code. Later I made an archive containing GORILLA.BAS compiled for eleven platforms!

Update (Aug/07/2024)

I've implemented support for Sord M5 and Memotech MTX computers in my CVBasic compiler v0.6.0, but wait, I went the last mile and implemented a full 6502 backend and library to support the Vtech Creativision and Dick Smith's Wizzard consoles!
From Japan, MAXXKAO bought my game Aardvark from the Atariage Store and writes about his experience.
I've scanned the Mexican manual for Lock'n'Chase for Intellivision.

Update (Jul/09/2024)

I've released the source code of CVBasic: my BASIC cross-compiler for Colecovision, MSX and Sega SG-1000. Now it also supports Spectravideo SVI-318/328!!!
Brian's Man Cave does a review of my book Programming Games for Colecovision.
I've made a video of my book Programming Games for Colecovision.

Update (May/15/2024)

Now available my new book Programming Games for Colecovision in hardcover from lulu.com, and also as ebook from my digital store!

Update (May/11/2024)

Now available my new book Programming Games for Colecovision in paperback from lulu.com.

Update (Apr/14/2024)

My new program is a Ray Tracer in 483 bytes of x86 machine code and, of course, runs from a boot sector! Inspired by an awesome program by D. Scott Williamson for Atari 8-bit BASIC.

Update (Mar/19/2024)

bootLogo is a Logo language written in 509 bytes of x86 machine code and runs from a boot sector! Inspired by my own LOCS.

Update (Mar/12/2024)

LOCS, my Logo-like language written at age 9 in 1988. I've found it in old papers.

Update (Mar/10/2024)

I've found a page of an even earlier printout of Viboritas when it wasn't called Viboritas.

Update (Mar/08/2024)

CVBasic v0.3.0 now available! Including SCREEN, MODE, BORDER, DEFINE VRAM, and more optimization. Now included the TMSColor utility for image conversion!

Update (Mar/05/2024)

CVBasic v0.2.0 now available! Including CONST, ON GOTO/GOSUB, INCLUDE, PLAY/MUSIC, and more optimization. Sega SG1000 support as extra!

Update (Mar/01/2024)

I've developed CVBasic, a BASIC language compiler for Colecovision consoles. The version 0.1.0 is now available for download!

Update (Feb/19/2024)

I wrote an article about my game Cubos developed in 1991 in 3K of Z80 machine code when I was age 12. I needed new code to solve its main bug.
Fifteen anniversary of going online with this website!

Update (Feb/06/2024)

I wrote an article about my game Viboritas developed in 1990 in 2K of Z80 machine code when I was age 11. I even found a 34-year-old bug.
The 240p Test Suite now includes MDFourier tests.

Update (Jan/25/2024)

I wrote an article about the translation of Mecha-9 to Japanese.
Copies of Thunder Soldier and Mr. Chess for Intellivision are now available at the Blue Sky Rangers store in eBay.
The 240p Test Suite now can use MSX2 and has a database of MSX BIOS, also MDFourier is in the works.

Update (Jan/10/2024)

I ported the Artemio Urbina's 240p Test Suite to Colecovision, MSX 1, and Sega SG1000. The full source code and binaries are released under GPLv2. https://github.com/nanochess/240pTestSuite_colecovision
I was present as exhibitor at the Retro Game Fest 2 celebrated Dec/16/2023 at the Marriot Courtyard Hotel.
I'm the 9th position assembler developer in Github over 98974 developers.
My book Programming Games for Atari 2600 reached again the 4th position in Amazon for Assembly Language.

See previous updates

Site created: Feb/19/2009. Last modified: Feb/12/2026