Video Buffer RevB

Conversion Boards

Various boards to convert from one chip to another. Unless stated otherwise, they are currently untested.

Mean Well GP25A13A-R1B Breakout

A breakout board for the 5-pin DIN plug on this tri-voltage Mean Well PSU.

Logic Analyser Breakouts

Breakout boards to simplify connecting various ICs to a logic analyser via Dupoint-style wires:

• MOS 6502
• MOS 6510
• Intel 8080
• CDP1802
• Zilog Z80
• Generic 40-pin
• DIP-16 breakout

YouTube Videos:

• Intel 8080
• Zilog Z80
• MOS 6502

D-sub Breakouts

Breakout boards for various D-sub type connectors:

• DE9
• DA15
• DB25

EPROM Converters

Boards to convert between different ROM/PROM/EPROM types:

• 2364 to 27128 ... for Commodore VIC-20 8KB ROMs (BASIC & KERNAL)
• 2716 to 2732 ... switch between two 2KB ROM images
• 2764 to 27128 ... switch between two 8KB ROM images
• 2764 to 68764 ... write a 68764 as a 2764
• 2764 to MK36000 ... read an MK36000 as a 2764
• 68764 to 2764 for reading ... read a 68764 as a 2764

DIN Breakout

A breakout board for 5/6/7/8 pin DIN connectors.

SMQD Converter

Idea is to use a surface mount crystal in place of the through-hole crystal. Why? Spectrum clones from the former Eastern Bloc tended to use 14MHz crystals which are not easy to come by anymore in through-hole form, but surface mount versions are.

Status

20-Jun-2025: Test boards have been fabricated, not yet tested.

Dual Soviet Western 40pin Socket

Soviet-era electronics used a 2.5mm pin pitch rather than 2.54mm/0.1" pin pitch we are accustomed to in the West. This can cause problems with larger chips as they need to be bent slightly to fit. Hence this idea to allow a Western chip to fit into a Soviet motherboard, like an Intel 8080A to replace a Soviet КР580ВМ80А.

Status

20-Jun-2025: Test boards have been fabricated, not yet tested.

Soviet 40pin Socket

The idea behind this design is to make a 2.5mm pin pitch IC socket for Soviet-era chips.

Status

20-Jun-2025: Test boards have been fabricated, not yet tested.

Soviet Keyswitch Replacement

Replacement designs for Soviet-era VM16 key switches.

Status

26-Jul-2025: Initial PCB tested, requires adjustments

DIP-64 (1.27mm pitch) Breakout

A board to bring out the pins of a 64-pin IC with 1.27mm pin-pitch (like the Yamaha V99x8 VDPs) to 2.54mm pin-pitch headers so it can be hooked up for experimenting with similarly-minded 2.54mm pitch stuff.

Simple Video Ouput Buffer

A very simple transistor buffer for converting RF-modulated video output to baseband video output by taking the video signal generated by the computer before it reaches the RF modulator can and passing it through an emitter follower.

Based on the design for the Sinclair ZX81 but could be used for other "quick 'n' dirty" mods to see if a computer is working.