One of the retro computer mailing lists I’m on recently had a side project go by about building a single board computer using a Hitachi HD63C09P 8-bit processor which is a descendant of the Motorola 6809. I followed along with interest and there were some small PCBs designed and when it got to the testing phase the project stalled because they couldn’t get the 63C09 to start up. For some reason the crystal wouldn’t start oscillating, or when using a full can oscillator the E...

My rev B IBM PC 5150 A couple of months ago I moved my IBM PC into the living room thinking that with a more prominent location I would use it more often. It’s fun to try out ancient software, or use the PC to connect to the occasional surviving BBS. I also like tinkering trying to use the PC to access the modern internet, or at least see if I can. I definitely won't be playing YouTube videos on it, but I can read reddit, or search Google. Because of the nice keyboard and no...

It'll never work like that! I bought a National Instruments AT-GPIB IEEE-488 ISA card last year intending to use it with HPDrive so that I could make an old PC pretend to be an HP-IB hard disk. I installed the HP-IB card in the old KT7A-RAID computer I’ve been using for doing lots of other retro things. Unfortunately the card had to go all the way at the end and the HP-IB connector was too large to fit on there which meant swapping the motherboard into a different case that...

A while ago I stumbled into a conversation between Eric Nelson and Rod Hull on twitter. Eric was mentioning that for a long time he has wanted to get a ZX Spectrum to add to his retro gaming collection, but living in the US they weren't exactly easy to come by and he also wasn't sure how hard it would be to make one work in the US. I jumped in and somewhat jokingly said that when he gets one I'll have it shipped to my house so he has to come over and play some air hockey. A...

A cassette adapter works, but is less convenient It’s been a while since I last made a PCB  but I finally had need to make another circuit board. The board I needed to make this time was a simple circuit that would be installed in a ZX Spectrum +2B which would bring the record and playback lines out to standard headphone jacks so an external source like a smartphone could be patched in instead of having to use one of those cassette adapters. It came about because when the...