Скачать или смотреть 🇺🇦🇷🇺 Пионер 2 (Pioneer 2) ZX Spectrum Clone: Part 1 (First Look) [

It seems that I never posted this Part 1 video - I'm currently working on Part 2. The Leningrad 2 was a development of the Leningrad 1, both versions of the Sinclair ZX Spectrum 48K. I'm not sure of the origin of this machine (see below) ... Soviet Russian motherboard (Ленинград 2) but Soviet Ukrainian case & keyboard (Пионер 2) ... ?

There doesn't actually seem to be a Soviet-era computer called the Pioneer-2 ... there was one called the Pioneer from the 1980s that used the 8080 CPU.

The consensus from my discussion with the Ukrainians vintage computer guys is that this is a home-brew ZX Spectrum clone using a Leningrad-2 motherboard (from 1991) and a keyboard from the Poisk (Поиск) IBM PC clone.

I still don't know what the explanation for the factory-produced looking text on the front fascia is:
Бытовой Персональный Компьютер Пионер-2
... or ...
Pioneer-2 Home Personal Computer

The only tangible information I can find about this machine is from a Ukrainian "for sale" post a few years ago - unfortunately the pictures were externally hosted and now lost to time:
https://phantom.sannata.org/viewtopic...

I do have some photos on my Patreon:
  / 143741793  

The board is mostly Soviet chips, including those lovely, green, precious-metal-containing KM-type capacitors.

The CPU is a genuine Zilog (dated 1990) and the two 8KB EPROMs are also Western.

The keyboard is interesting ... it uses the mechanism from the Poisk but has Spectrum-specific keycaps and a hand-built circuit board. Quite the amalgamation. I can really admire the amount of effort that went into building this Spectrum compatible keyboard PCB, with dedicated number pad as well.

I have my doubts, though, that this keyboard will work well, or at all, after 30+ years. The contacts look pretty oxidised and some are shorted.

I've whipped up a replacement PCB using 12mm tactile switches as a replacement, if required. I've also designed a converter board for the Leningrad-2's expansion bus which is 2x32 at 2.5mm Soviet pitch. The converter board exposes this bus to a standard 48KB Spectrum 2.54mm pitch edge connector so that, maybe, I can try connecting a peripheral or two. The Leningrad doesn't have the !ROMCS or !BUSACK signals on the bus but that should be okay if I want to just use a DivMMC ... ?

Both of these are on my Github:
https://github.com/0ddjob/ZX_Spectrum...

One nice design decision is the use of a DIP-16 socket for the keyboard connector (blue in top-left near joystick DIN socket), rather than being soldered on directly - so much easier to work with.

Some useful links (Russian):
https://sblive.narod.ru/ZX-Spectrum/L...
http://micklab.ru/ZX%20Spectrum/Lenin...
https://usamodelkina.ru/23731-sobirae...

00:15 ... Intro
02:00 ... Keyboard
06:25 ... Leningrad 2 motherboard
08:00 ... Internal power supply
09:00 ... Dismantling to clean
13:30 ... Motherboard closeup
17:10 ... Keyboard again
20:00 ... Motherboard cleaned
21:40 ... Channel thanks & outro

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  / thecluelessengineer  
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Music by Karl Casey @ White Bat Audio
https://karlcasey.bandcamp.com
   / @whitebataudio