Author: Allen Huffman

In 1982, I received my first computer: a $299.99 Commodore VIC-20. A year later, I moved on to a 64K Radio Shack Color Computer ("CoCo"). In 1990, I co-founded Sub-Etha Software "in Support of the CoCo and OS-9". This later led me to a job at Microware, creator of OS-9. I am author of the CoCoFest Chronicles, a compilation of my fest reports covering the 1990s era. I also host the CoCopedia.com wiki. These days, I am enjoying excavating my original VIC-20 tapes and thousands of CoCo floppy disks...

Some things about strings in Color BASIC

February 8, 2023 3 Comments on Some things about strings in Color BASIC
Posted in BASIC, TRS-80 Color Computer (CoCo)

NOTE: If what I describe in this article applies to other implementations of BASICs that use reserved string space, please leave a comment and let me know. I was in junior high school when I started learning to program BASIC. Initially, this was done by reading a book a classmate had and then writing programs out on paper. We’d then…

Tandy CoCo 3 CLS 100 easter egg explored

February 1, 2023 2 Comments on Tandy CoCo 3 CLS 100 easter egg explored
Posted in TRS-80 Color Computer (CoCo)

The most famous Tandy/Radio Shack Color Computer (“CoCo”) easter egg has to be the hidden photo of the CoCo 3 programmers that shows up if you hold down CTRL-ALT while turning the machine on. (Alternatively, you can hold down CTRL-ALT and hit the reset button on the back of the machine to also display it.) I had the pleasure of…

Microsoft’s undocumented TRS-80 Color BASIC syntax

January 27, 2023 3 Comments on Microsoft’s undocumented TRS-80 Color BASIC syntax
Posted in BASIC, TRS-80 Color Computer (CoCo)

Although I started out my home computer life with a Commodore VIC-20, I ended up moving to a 64K Radio Shack TRS-80 Color Computer (“CoCo”) mostly because of its Microsoft Extended BASIC. Having built-in commands like PLAY, DRAW, PAINT, LINE and CIRCLE let me do graphics that anyone with an Extended BASIC CoCo could run. On my VIC-20, I had…

ChatGPT A.I. writes a BASIC program

December 7, 2022 3 Comments on ChatGPT A.I. writes a BASIC program
Posted in Announcement, BASIC, Programming, TRS-80 Color Computer (CoCo)

Previously, I shared my discovery that the new ChatGPT artificial intelligence program had some understanding of programming languages such as C, BASIC and even COBOL. In the days since that discovery, I have continued to experiment with this technology and have found it to be quite useful. It has already helped me with my day job. It was able to…

ChatGPT AI knows BASIC, assembly, and more…

December 2, 2022 2 Comments on ChatGPT AI knows BASIC, assembly, and more…
Posted in BASIC

OpenAI is the entity behind the trendy DALL-E art generator that creates images using artificial intelligence. That’s the thing that’s been creating nightmare fuel images like this one of “a robot using a 1980s home computer inside a Radio Shack.” Recently, they opened up their ChatGPT chat bot and the world may never be the same. When I first tested…

CoCo 3’s NitrOS9 “Ease of Use” edition on your PC/Mac

July 8, 2022 0 Comments on CoCo 3’s NitrOS9 “Ease of Use” edition on your PC/Mac
Posted in TRS-80 Color Computer (CoCo)

Updates: 2002-7-9 – Corrected information on the company that originally released NitrOS9 (thanks to L. Curtis Boyle, one of the developers). TL:DNR Put six files in a directory: 68IDE.ide bas11.rom coco3.rom hdblba.rom xroar.conf (which you will make, below) xroar.exe (or xroar.app for Mac) Where “xroar.conf” contains the following text: machine coco3 tv-input rgb machine-cart ide cart-rom hdblba.rom load-hd0 68IDE.ide kbd-translate…

Reverse engineering Tandy’s CoCo 3 “GIME” chip, updates.

December 4, 2021 0 Comments on Reverse engineering Tandy’s CoCo 3 “GIME” chip, updates.
Posted in TRS-80 Color Computer (CoCo)

It has only been a week since Roger Taylor announced his project to reverse engineer the custom ASIC Radio Shack used in their Color Computer 3 and we have already learned a few interesting things. He sent two versions of the “GIME” chip off to be opened up and photographed under a microscope. These images revealed some messages etched in…

Reverse engineering Tandy’s CoCo 3 “GIME” chip.

November 30, 2021 4 Comments on Reverse engineering Tandy’s CoCo 3 “GIME” chip.
Posted in TRS-80 Color Computer (CoCo)

When Radio Shack released their third and final version of the Color Computer, the Tandy Color Computer 3, it included a custom ASIC chip. This chip, called the GIME (Graphics Interrupt Memory Enhancement), replicated most features of the Motorola 6847 video display generator chip used in earlier models. It also added new features such as higher resolution graphics with more…

The CoCo’s lesser-known screen color, revisited again.

November 25, 2021 4 Comments on The CoCo’s lesser-known screen color, revisited again.
Posted in TRS-80 Color Computer (CoCo)

Well, this is getting a bit silly. Awhile back I posted an article discussing the alternate color set available in the 32 column text mode on a Radio Shack Color Computer. It was (mostly) available from Extended Color BASIC via the SCREEN command. This allowed having a screen that was either “nuclear green” or “whatever color the other is”. Then,…

The CoCo’s lesser-known screen color, revisited.

November 18, 2021 3 Comments on The CoCo’s lesser-known screen color, revisited.
Posted in TRS-80 Color Computer (CoCo)

In a previous article I discussed the Radio Shack Color Computer’s lesser known text mode screen colors. Below you can see the normal, normal reversed, alternate and alternate reversed color modes: During a recent discussion with CoCo FPGA programmer Roger Taylor, he mentioned something I was unaware of. He has spent years working on an FPGA recreation of the various…