The miscellanea of an A/V Tech’s projects.
ALT When I built the 8-port serial card for Wrap030, my 68030 homebrew computer project, I omitted support for interrupts. The reason why is already lost to time. Perhaps I couldn’t figure out how to pull it off with the board space I had left; perhaps I didn’t think it would be necessary. No matter the reason, the result is the same — to get any data in or out, the CPU must…
commodorez : The first Cactus keyboard prototype has been assembled! You will note the distinct lack of a microcontroller, or any large IC’s on board. This is a classic parallel ASCII keyboard, done with pure 7400 series jellybean logic to scan the keyboard matrix. No shortcuts here! It has a few bugs already, and plenty more left to find. @commodorez once again doing things on Hard Mode and…
Show me some of them 👀 also yeah my monitor weighs 42lb lmfao virescent-phosphor : Early 80s Zenith with computer running on it and "too new" consoles (ps2 and switch) so the pitch on the text is bad... Running a split composite cable to a capture dongle Bonus tower of power Spengbab tv in an aesthetic spot Evil new years setup "Portable" setup Bonus 2: good monitor I see nothing wrong here. All…
fishmech : ui-alcoholic : Macintosh IIcx (1989) There’s something quietly iconic about the IIcx: a workstation-era Mac that looks restrained, tidy, and confident. Same 68030-era muscle as its bigger sibling, but in a slimmer case that feels more “designed” than “industrial.” Motorola 68030 @ 16 MHz — fast, serious, and very late-80s pro 3× NuBus slots — enough room for real expansion without the…
ALT I fell down a bit of a rabbit hole this week. It started when @commodorez shared the image above. I’m a sucker for good design (having studied it for my bachelor’s degree) and this is a beautiful bit of illustration. It looks like it’s from a catalog or something of the sort, but the actual source was unknown. I would love to know where it came from and hopefully find a…
Two of my terminals have been complaining about uninitialized settings on power up. It’s time I took care of that. First up is my Wyse WY-55. I’ve tried opening this one before, but never could figure it out and there are no service manuals to be found. It only has two screws on the back, but something holds it together on the top. I eventually found it has two rather large plastic…
Wow what a weekend! We had well over 1500 guests and over a hundred exhibitors & vendors. There were 17 scheduled workshops & presentations, plus MDCon, a game room, consignment, and more. I walked 20 miles inside the convention center, talked until I lost my voice, spent far more than I should have, and gave away hundreds of stickers. ALT I exhibited my PikaPC prototype and phase 2 board stack,…
ALT Today ! (and tomorrow, and Sunday) If you are in or near the Dallas / Fort Worth area, come check out VCF Southwest this weekend. Over a hundred vendors & exhibitors, workshops, discussions, presentations, a charity auction, consignment, free/swap tables, and more!
ALT I left off last week with my revised PikaPC host card briefly running code but crashing before it could fully boot to the forth prompt. As best as I could tell it was crashing when returning from a subroutine, which could indicate main memory still was not working. I started by probing the DRAM control signals to verify that memory bank was getting properly initialized as DRAM and accessed as…
I’ve not said much about the new modular phase 2 PCBs I made for my PikaPC project since they arrived . Well, that’s because they’re still not working and I can’t figure out why. I was able to get some signs of life out of the host card. It did appear to be running code at least, but it was never able to boot to the PPC Forth prompt. Such a disappointment after how easily I…
ALT If you’re in the area, make plans to stop by! We’re in a new venue this year, all under one roof. This year we have over a hundred vendors and exhibitors, workshops, discussions, presentations, a charity auction, consignment, free/swap tables, and more! See VCFSW.org for more information about the show. I will be exhibiting my PikaPC project and I’m also planning on bringing…
I need a better PowerPC development toolchain. What I’ve been using is broken and incomplete. Were my main computer running … well basically anything other than Windows, getting a cross-compiler running would be pretty straightforward. But I’m not in a position right now to switch to something else. Sure, I could easily spin up a VM and set up a cross-compiler that way. But — what if…
I have been working on improving video output for my PikaPC homebrew computer. When last I left off, I was able to initialize the video chip to output 320x200 video, but it was only outputting 4 colors instead of 256. I really wanted to get it into the proper 256 color mode. I never did figure it out. Throughout this project, I’ve been referencing an annotated disassembly of the Trio64 VBIOS…
Finally, I have video working on PikaPC, my PowerPC homebrew computer. I’ve adjusted my Forth Mandelbrot program to draw on screen instead of over the terminal. But surely I can do better, right? One of the original goals of this project was to get the proper tools and development environment set up for writing PowerPC code, but I’ve spent all my time writing Forth code for it.…
I’ve been working on bringing up the video card for PikaPC, my PowerPC homebrew computer. This is a custom card I designed to support the S3 ViRGE or Trio64V+. I’m using the latter for now because ViRGE was known to have some bugs in its VLB support. Last week I was finally able to work out a wiring error that was preventing me from accessing the chip and get it to output a valid video…
rohirric-hunter : “We’re gonna achieve immortality by turning ourselves into machines” buddy I want you to find yourself a 15 year old laptop and try to run a 10 year old piece of software on it please. Connect to the internet, if you can, and attempt to log into any of your online accounts Good luck cyborg buddy, I wish you the best. Capacitor plague - Wikipedia Transistor aging…
I’ve been working on bringing up the video card for my PikaPC project. It has had me quite confused. No attempt to communicate with the device had any effect. ALT Everything I was sending it looked right. Address decoding asserted the chip enable, the state machine on the video card recognized it was being addressed, the emulated VLB cycle started. There only thing that was missing was some…
I’ve been bouncing around a lot. After confirming my new bus interface was working on my wire-wrap prototype, I built out the DRAM card. It … mostly works. It will work just fine for a few thousand back-to-back transactions and then it just randomly locks up. The CPLD running its timing sequence will freeze on one state and stop responding to any further input. I managed to chase down a few…
I have the first signs of life from the new bus on my PikaPC prototype! The logic ended up being quite a bit less complex than I expected, using only 32 macrocells. It’s just simple state machine written in verilog. I did have to rework my plan for bus cycle timing & handshaking to work around more quirks of the PPC403’s weird bus interface, but it does work. This took me even further…
tumblr : Reblogs in a chain now get their own notes The reblog chain is one of the things that makes Tumblr unlike anywhere else. All the notes on reblogs are attributed to the original post, no matter which branch people actually liked or reblogged. We want to keep encouraging conversations, and give contributors the recognition they deserve. Soon, you’ll be able to like , reblog , or reply…