17-10-2026, 10:09 PM
(This post was last modified: 17-10-2026, 10:13 PM by aladinsane.)
Time for an update. Both of my machines live again 
Both had faulty PIO-chips and one of them had a semi-defunctional 6545 chip. Both machines had shorted 7805 and completely dead keyboards.
Replacing the faulty chips was easy enough once I identified the faults - and a big thank you for all the help and pointers! The keyboards was a pain and I really do believe that I qualify for full membership of the "Microbee Keyboard Renovation Club"
I desoldered 2x 60 keys, dismantled them, cut of a extremely thin sliver of the conductive carbonized rubber, cleaned the pads, reassembled them and re-soldered all 2x 60 keys.
Then I could type in a few programs but it took me some time to figure out that I had to use LOADU? "" in order to load anything from tape and WAV files. But now everything seems to be in order and I two fully functional machines - one 32K and one 16K.
I celebrated the success by diving into Z80 assembly. I'm more familiar with 6502 for Apple II, NES and C64, but I have made a few thing for Sinclair ZX81. However, I soon discovered that the graphics is handled quite different Well, the result is a small graphics viewer for both HIRES and LOWRES images.
Once again: thank you all for your help
Btw, one machine is enough for me, so I'll probably unload the other at some point. I don't plan to get rich from a sale, but what should I demand if I don't want do cheat myself?
Both had faulty PIO-chips and one of them had a semi-defunctional 6545 chip. Both machines had shorted 7805 and completely dead keyboards.Replacing the faulty chips was easy enough once I identified the faults - and a big thank you for all the help and pointers! The keyboards was a pain and I really do believe that I qualify for full membership of the "Microbee Keyboard Renovation Club"
I desoldered 2x 60 keys, dismantled them, cut of a extremely thin sliver of the conductive carbonized rubber, cleaned the pads, reassembled them and re-soldered all 2x 60 keys.Then I could type in a few programs but it took me some time to figure out that I had to use LOADU? "" in order to load anything from tape and WAV files. But now everything seems to be in order and I two fully functional machines - one 32K and one 16K.
I celebrated the success by diving into Z80 assembly. I'm more familiar with 6502 for Apple II, NES and C64, but I have made a few thing for Sinclair ZX81. However, I soon discovered that the graphics is handled quite different
Well, the result is a small graphics viewer for both HIRES and LOWRES images.Once again: thank you all for your help
Btw, one machine is enough for me, so I'll probably unload the other at some point. I don't plan to get rich from a sale, but what should I demand if I don't want do cheat myself?