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Breadboard to circuit layout
09 Mar | 14This is part 2 in a series. Check out Part 1: Creating a circuit and Part 3: Milling the PCB . Prototype on breadboard In order to make my own PCB for the CGA to analog converter project , the first step is to do what is called schematic capture, and get the schematic drawn in the computer. While it’s certainly possible to draw a schematic in a program like Paint, or using something more sophisticated like Illustrator, using a specialized program is a better choice...
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CGA/RGBI to analog for the Commodore 128
05 Mar | 14This is part 1 in a series. Check out Part 2: Using KiCAD and Part 3: Milling the PCB . When I got my Commodore 128 I was expecting I would just connect the RGBI TTL output to the GBS-8200 knockoff that I have been using with the BBC Micro’s RGB TTL output. Of course the moment I went to do that I realized that I had an extra pin for Intensity with no place to connect it. I found several circuits online that were supposed to convert the 4 bit TTL output to an analog...
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On the Interwebs. Sort of.
27 Feb | 14After getting the Mac SE upgraded to 4 megs of RAM and a working internal HD, the next thing to do was to see if I could get a working web browser on it. The SE doesn't have an ethernet card, but it does have built-in AppleTalk networking. I have plenty of PhoneNet adapters. I ended up using another Mac ( the one that I fought to put Linux on ) running MacOS 9 and LocalTalk Bridge to move traffic from LocalTalk to Ethernet and back. It worked well and I was able to mount a share from a...
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Video demo of the Pi acting as a disk drive
04 Aug | 13I've made some more progress on my software that allows the Raspberry Pi to act as a Commodore 64 disk drive. I was amazed at how much more of the IEC protocol was missing from the documents I have. One of the things that I found a little strange about the IEC protocol was there was no way to specify how much of the data you want. Once you say go, the sender is just going to send it all. It turns out that when ATN is asserted it doesn't mean abort , it just means pause. Took quite a...
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Making a Raspberry Pi into a unified retro peripheral
21 Jul | 13If you've been following along here or on Twitter or Google+ you've no doubt seen the experimenting I've been doing with interfacing a Raspberry Pi in various ways with several retro computers like the Atari 800 and Commodore 64. My first project was using the Raspberry Pi to act as a converter for a USB gamepad to turn it into an Atari 2600 style joystick. After discovering Eric Nelson on Twitter and seeing all the games he was playing on the Commodore 64, I really wanted to...
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