Guest
Still trying to get software loaded - not sure what the issue is. I checked the op. amps (140УД6) and the output looks okay, particularly going into pin 10 of the 8255 ... although the “low“ voltage is negative ... ? I don't have any tapes or original WAV files to work with - I only have RKP-format files that I've converted to WAV (compiled the C-source code on my Mac): So is the WAV conversion correct ... or still some issue with the processing of the input signal into the 8255? I know, I should save a chunk of memory and compare ... but I couldn't figure out how to save using the Monitor commands (yes, dunce hat for me for not speaking Russian). More details about the Partner can be found here: ... or here (with OCR'd text): From the Part 1 video: It's a machine built in 1990 and looks to be quite well made with a magnetic reed-switch keyboard (more about that in a future video). It's actually based on the Radio 86RK (Радио 86РК) homebrew/DIY computer. Incredibly easy to get into, to pull apart, clean and to service - keyboard, motherboard and PSU all unplug from each other. Nice. The machine has three 27C64A EPROMs and four cloned Intel chips: КР580ВМ80А (KR580VM80A) = Intel 8080 clone КР580ВВ55А (KR580VV55A) = Intel 8255 clone (PPI) КР508ВТ57 (KR508VT57) = Intel 8257 clone (DMA controller) КР580ВГ75 (KR580VG75) = Intel 8275 clone (CRTC) On the left side it has a cassette port (МАГ), a video output (ТВ) and I assume a 5VDC output ( 5В). On the right side it looks to have a home-made joystick port - a DIN socket (surprise!) that is connected to the cursor keys on the keyboard.
