tim lindner's personal blog
Here is my second proposal for the authors of GIME FPGA/CPLD devices: [https://tlindner.macmess.org/?p=1103] As a reminder the first one was: [https://tlindner.macmess.org/?p=977] This proposes adding a single hardware graphic cursor avaiable in both text and graphics modes. An emulated example is … Continue reading →
# GIME Hardware Cursor Extension Proposal ## Overview The GIME video system can provide a hardware mouse cursor by adding a small independent cursor overlay. The cursor is not stored in normal CoCo memory and does not require software to … Continue reading →
Reading CoCo Joystick Buttons in Color BASIC The joystick buttons on the TRS-80 Color Computer 1 (CoCo 1) are connected to the PIA (Peripheral Interface Adapter). They can be read from memory location $FF00, which is decimal 65280. In Color … Continue reading →
I recently ran into a problem while processing a large batch of OCR text files. The workflow was simple: scanned PDFs → OCR → text files → BBEdit search. The OCR output was fine structurally, with one line per paragraph, … Continue reading →
Reverse Engineering the CoCo Speech/Sound Cartridge Sound Activity Circuit The Color Computer Speech/Sound Cartridge (S/SC) was one of the more ambitious peripherals Tandy produced for the CoCo line. It packed a TMS-7040 microcontroller, an SPO256-AL2 speech synthesizer, an AY-3-8913 programmable … Continue reading →
I’ve been a Homebrew users for a long time. Very nice experience. My only complaint is using it with old operating systems is not a thing they optimize for. But with regard to ToolShed, the disk image tool I contribute … Continue reading →
I recently thought it would be nice to have a picture of every video mode a Color Computer could produce. So I wrote a program to make it easy to do that. You can find this program over on github. … Continue reading →
I wrote a newish 6809 and 6309 disassembler. https://www.macmess.org/follow9.html. Its just two files, an HTML and JavaScript file. Copy them locally, host them on another site, what ever. There is also a git hub so you can do a pull … Continue reading →
Demon Attack cartridge (26-3099) has a small bug when running on a CoCo 3. The Programmer’s credit and version information is drawn using garbage rather than the correct data from the ROM. This has to do with setting bit 3 … Continue reading →
The second PIA has a smaller mirror in the CoCo 3 than the CoCo 1/2. It goes from $FF20 to $FF2F. The CoCo 1/2 mirror is from $FF20 to $FF3F. Recently I was challenged to find a citation for this … Continue reading →