Байт (Byte): Part 4 (RGB cable & СИСТ expansion)
18Thanks to Yevhen on the Discord for posting the 5-pin RGB pinout - made up a cable and confirmed.
Pin 1 = synch (СИ)
Pin 2 = ground (0В)
Pin 3 = blue
Pin 4 = green
Pin 5 = red
I played another game of Rodmän, this time using the Kempston cursor keys on the right of the machine. Worked pretty well.
@adamradipat1715 also confirmed on the Discord what type of connector is used for the 32-pin/3-row СИСТ (SYST) expansion bus ... a DIN 41612 ... but with 2.5mm spacing instead of 2.54mm (0.1") spacing ... dah!
That's only 0.04mm per pin but after 31 pins there's a 1.24mm difference in spacing which is enough to prevent them from mating.
The relevant Soviet-era connectors ... СНП59-96 (SNP59-96) ... are still available in Ukraine (thanks to Yevhen on Discord for the link).
https://zapadpribor.com/snp59/
So a simple solution ... provided you can get the connectors ... is to prototype a converter PCB to take a right-angle SNP59-96 receptacle (with 2.5mm spacing) ... СНП59-96РП3? ... on one end and a ZX Spectrum edge connector on the other end ... and connect the relevant pins between them. Simples!
Other videos in this series:
https://youtube.com/playlist?list=PL5pwokf56wMKVnDysV5jL_ms7uXbMGNxi