After bit of blind search I found the correct set up for #Elwro Junior 800 replica: #RGBtoHDMI with #Amstrad CPC and change od sync to V+H+

And it works! Polish replica by Przemysław Węgrzyn with help from Mikołaj Cichal and the whole #Elwro 800 Junior group - works fine when used with Polish UCY74LS04. CEMI, you better ramp-up the production lines. Thanks to all involved, it was great fun! #reteoreplica #z80 #zxspectrum

#Elwro Junior 800 keyboard replica - first keycaps and switches are in place

Did you know? Back in the 80ties Poland's #Elwro created quite good #ZX #Spectrum compatible Junior 800. With education in mind, they added networking! Now - thanks to Przemysław's hard work - you can build a Full replika with this open source project: https://github.com/codepainters/e800j