🇷🇺 Quantum (Квант БК) ZX Spectrum Clone: Part 1 (First Look) [#TCE0692]

Thanks to #PCBWay for their ongoing support! https://www.pcbway.com Ad-free version on my Patreon ...   / thecluelessengineer   Let's have a look at another Sinclair ZX Spectrum clone - this one was built in post-Soviet Russia (1992). I managed to figure out the RGBS pinout, but the machine has problems that I need to investigate & resolve. Note - the КВАНТ (Quantum) name is used on multiple, unrelated machines so it can be hard to find relevant information. There is some for this particular machine here: https://polymus.ru/collection/detail/... I was pondering how to translate the full name: the БК is short for Бытовой Компьютер (household/home computer). We don't really use the acronym "HC" in the West for a home computer or home micro so I've just left it off the English translation of the name. I hope that offends the least number of people. This machine uses uses Soviet-designed "super ULA", the БМК (Базового Матричного Кристалла, or Basic Matrix Crystal) which means a Speccy can be implemented with very few chips. It has a decent array of ports on the back, from left to right: СБРОС = reset button ДЖ = joystick (джойстик) ЗВУК = sound/audio ЦТВ = colour TV (цветное телевидение) МГ = cassette (мачнитофон) 5В = 5V power input Unusually the video output uses all five pins on the 5-pin DIN connector for video signals - usually it's RGBS with ground on pin 2, but in this case ground is on the shield. What I've figured out is: Pin 1 = composite sync Pin 2 = intensity? Pin 3 = R, G or B Pin 4 = R, G or B Pin 5 = R, G or B Shield = ground (not sure exactly which colour is which pin yet) 00:00 ... Thanks to PCBWAY for sponsoring! 01:20 ... Intro 02:55 ... Ports 04:00 ... Opening the case 07:30 ... Power input pinout 08:30 ... Figuring out the video pinout 13:30 ... Oscillograph action 17:20 ... Power on (NOK) 19:00 ... Checking Z80 signals 25:35 ... Channel thanks & outro -------------------------------- Check out my Patreon for regular blog-type updates between videos - there is a free membership tier and two paid tiers (US$2 and US$5). There is also a one-week trial for the paid tiers so if you don't think it's worth it, then cancel ... no hard feelings ... I appreciate any support, even if it's just subscribing to my YouTube channel!   / thecluelessengineer