Post #1956392

2026-05-03 09:55 UTC

Anyone know anything about the &quot;PDS&quot; - Programmers Development System - used to program 8-bit computers from early PCs? Information about it seems very sparse online... As far as I can see, it hooks up the PC end Intel 8255 IO interface to a Spectrum end Z80 PIO and then has a software protocol running over the IO lines to get code across to the target device. #RetroComputing #ZXSpectrum

Replies (4)

@diyelectromusic@mastodon.social 2026-05-03 14:15

Ok, can someone tell me either I'm not going crazy and the schematic doesn't match the board, or what obvious thing I'm missing... https://www.cpcwiki.eu/index.php/PDS_development_system Look at the schematic and board diagrams for the remade PC card. The schematic shows D0-3 on the two connectors going to different 244 ICs. But I'm pretty sure the board shows D0-3 on both connectors linked and going to the same 244. Look at pin 11 for three 244s...

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@Workshopshed@mastodon.scot 2026-05-03 10:19

@diyelectromusic that would have been easier than my method of loading from tape!

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@TCD@oldbytes.space 2026-05-03 11:11

@diyelectromusic In this video around 8 minutes in they talk about the PDS: https://www.youtube.com/watch?v=S6DlSfEj0as In some other video from the Retro Collective featuring Jason Daniels he shows the PDS in action, but I couldn't find that video quickly.

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@jandi@mastodon.social 2026-05-03 11:14

@diyelectromusic Yeah, I was a kid back then, but when I listen to the retrocomputing podcasts in spanish (like "El mundo del Spectrum" and others), PDSs are featured prominently, and many programmers remember distinctively the moment they were introduced to them, how they sped up development, specially of conversions, etc. There's decent info here: https://www.worldofsam.org/products/pds-development-system

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