Икар 64 (Icarus 64): Part 2
35The Icarus is a Sinclair ZX Spectrum clone (бытовой компьютер or "household computer") that was first built in the Ukrainian SSR, and then independent Ukraine (1991-1993) ... as far as I can tell.
Big thank you to @rukzak1 who correctly pointed out the issue - ROM!
For some reason it appears that the ROMs were installed not only in the wrong sockets but also upside down!
I noticed that the sockets had the pin 1 notch at the bottom of the board, but the ROMs were installed with pin 1 towards the top of the board. I confirmed also by checking where GND (pin 14) and VCC (pin 28) were located and confirmed the sockets were correctly oriented.
However simply re-inserting the ROMs the correct way around made no difference.
I dumped both ROMs ... К573РФ6А ... equivalent to 8KB 2764 ... and compared with the standard Sinclair ZX Spectrum 16KB ROM.
The ROM labelled U30 has the low 8KB bank and the U29 one has the high 8KB bank.
I tried swapping them around and the machine finally booted:
U30 (low 8KB) should be in the left socket and U29 (high 8KB) should be in the right socket.
Regarding the [RESET] button - there are two - it seems pressing both will reset the computer.
ROMs can be found here if interested:
https://github.com/0ddjob/Icarus64
Test ROMs:
https://zxbyte.ru/test_rom_for_zx-spectrum.htm
Other videos on the Icarus 64:
https://www.youtube.com/playlist?list=PL5pwokf56wML7hP6DnaWvj01D7IUqEIIh