Early Sunday was used to solder the last lines of the #KramerMC memory expansion. All lines are beeped, correct and not shorted. Now I have to wait for my memSIM2, which is in repair in the moment. The voltage regulator was melted, no one knows exactly why.
#RetroComputing #FormerGDR #KitComputer #ZilogZ80 #U880

Productive evening. Most of the work is done for the #KramerMC memory expansion. It only lacks of the voltage and controlling lines. But data & address bus are connected. Have to beep it out before doing a first test, maybe on Sunday.
#RetroComputing #64kB #FormerGDR #KitComputer

Thanks to @breakintoprogram for his youtube introduction how to program a GAL22V10. I decided for this way and against multiple 74LS chips. I did not find a good documentation about galasm, the link inside the github project is dead. Is it possible to use braces within the expression?
D0-D7 and A0-A10 are wired at the #KramerMC memory expansion. Rest has to be decoded.

After some searching I found the problem in #KramerMC. The #DS8286 on the cpu board gets in the way. In addition, it is installed incorrectly because the inputs and outputs are bridged. When I leave the socket empty it runs fine. Wonder if the computer ever worked the way it was intended.
Since I still had two of the plug-in contacts for the bus system in stock, I'm starting to build a RAM expansion to 64k. With address decoding to spare out 0000-0fff (ROM 2732) and 0fc00-ffff (display RAM). Because of the simplicity I decided to use 64k static RAM.
I'm also curious if the buddy might bring a new CPU board today, I'll be surprised.
#RetroComputing #Z80 #U880 #FormerGDR

The #KramerMC is doing things 😀​ I've no idea whats going wrong with it at the weekend. Have changed nothing, but now my small "Write chars to screen buffer" is working well. Sorry for the wrong orientation, but seems to be automatic.
And btw the selfmade new circuit board is ordered.
#RetroComputing

You like some #KramerMC news? After the last try it doesn't work properly again. Which doesn't surprise me with the catastrophic condition of the CPU board. I'm tired of looking for broken wires/cuts again and again. We decided that a colleague in the museum would etch the whole thing again from scratch. And I would then build a "new old" one, of course with the original parts.
At the moment I'm revising the layout scanned in 1200 dpi in GIMP. It's always a bit of a loss when it's 35 years old and printed on extreme eco-friendly paper.
#RetroComputing #Zilog #U880

Where are empty EPROM if I need them?? Want to reprogram the character set ROM of the #KramerMC but none of my 2716 is empty 🤔​ I should make a batch deletion of all inside the "can be used" box further.

Said and done. No problem to compile "The Macroassember AS" under #Debian. Only needs a "cp Makefile.def.tmpl Makefile.def" before starting make. It's worth a closer look, by the way, because it can generate binaries for dozens of microprocessors. Absolutely impressive:
http://john.ccac.rwth-aachen.de:8000/as/cpulist.html
#RetroComputing #KramerMC #Z80 #Assembler

After a long time I decided to take another look at our #KramerMC. I made good progress tonight and I think I'm on the right track. I can compile a downloaded listing using "The Macroassembler AS" on Windows. Since this is available in the source code, it should also be possible to create it under Linux. Then start #JKCEmu - simply the best, only needs Java - as an alternative ROM.
#RetroComputing #Zilog #Z80