🇺🇦 УМПК-Р (UMPK-R): Part 3 (Video output troubleshooting continues) [TCE #0546]
24Just continuing on trying to get a video signal out of the machine, similar to the modern РАДИО-86РК implementation before I continue troubleshooting the rest of the machine (if required).
The manual (in Russian) can be found here:
https://www.patreon.com/posts/umpk-r-manual-115886138
Sergey's excellent reproduction of the Radio 86RK:
https://github.com/skiselev/radio-86rk
00:00 ... Intro
03:10 ... What the video signal should look like
07:10 ... HRTC output from 8275
07:50 ... VRTC output from 8275
08:30 ... Combined HRTC & VRTC signals
09:30 ... Character data
10:30 ... Checking the УМПК-Р
12:00 ... HRTC & VRTC from the КР580ВГ75
16:20 ... Character data - NOK
16:45 ... Video output from УМПК-Р - NOK
18:25 ... Made new video output circuit (based on Sergey''s design)
20:00 ... Still no video output - comparing the circuits
21:15 ... Comparing УМПК-Р video output with Sergey's design
23:04 ... Channel thanks & outro
From Part 1:
Here we have another "serially produced" version of the Soviet-era home brew computer Радио-86РК (Radio-86RK) based on their Intel 8080A equivalent, the КР580ВМ80А (KR580VM80A). This fellow comes from Мукачево (Mukachevo) in the Ukrainian SSR (as far as I can tell). There was a 16KByte version (УМПК-Р16) and this 32KByte version (УМПК-Р32).
It is a pretty simple machine, nicely made if we ignore the membrane keyboard with a dozen space bars. It has a four-pin socket for power in, a 5-pin DIN for cassette, RF-output for TV and a DN4612-style expansion port (СНП?).
As it's an 8080-based machine it requires ±5VDC and +12VDC.
My understanding of the special keys on the JCUKEN keyboard layout (thanks to @Mercury13kiev & @sergijtolmeros for their input!):
[ВК] = Возврат Каретки = carriage return
[ЗБ] = ЗЗабой = backspace
[СС] = Специальные символы = special characters
[ПС] = Перевод Строки = line feed
[СБР] = Сброс = reset
[УС] = Управляющие символы = control characters
[АР2] = Автоматический Режим 2 (automatic mode), or more recently Альтернативный Регистр 2 (alternate register)
[СТР] = Система Трансформации Реальности, or [CTRL]
ВКЛ = Бключить (turn ON)
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