Re: 8085 processor questions
Righto, Power supply now repaired - a 5v regulator had decided to act as a short circuit.
A list of "Big" ICs on each board.
CPU Board
D8251AC
D8259AC
D8253C-5
Program Eprom
Printer Drive Board/Decoder Board
D8243C
D8741AD
D8039HL
2 Eproms
D8259AC
D8251AC
D8243C
D8253C-5
D8039HL
1 Eprom
Keyboard
D8039HL
22-950-38
FX1 059
1 Eprom
There are also 2 memory boards - from the description of the German machine that is similar, these two cards are only used for message storage functions, so as far as I can tell these will have little bearing on the basic start up of the machine.
The display driver board has a large selection of 74 series logic chips, which I guess must take the data from the CPU and convert it to something that the monitor understands.
Roger, I will have a rearrangement in the workshop to get the machine and scope closer together, so that I can take some screenshots of what is happening.
Cheers
Sean
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Engineers make things work and have spare bits when finished
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