ZMJC Computer
Introduction
During my MSc in Electrical and Electronic Engineering at The University of Nottingham (1992-3) we used this single boad computer for an assembly programming module. It must have been designed by one of the university staff, but I don't know who; it is just labelled "© 1991 MJC". Hence, I will refer to this as the zMJC Computer. I lost the schematic many years ago.
Key features:
- Z80180 CPU (z80 compatible) running at 6 MHz
- 256 KB EPROM
- 8 KB RAM (32 KB or 128 KB options)
- 8 bit switch input
- 8 bit LED output
- RS232 option
- ZN559 DAC option
- AD7828 OR ACD0809 ADC option
It is intended that this page will ultimately document the schematic and repoducible PCB layout after I have reverse engineered it.
Connectors
CON1 provides connection to the ADC and DAC options.
Pin | Function | Pin | Function |
---|---|---|---|
1a | 1b | ||
2a | 2b | ||
3a | 3b | ||
4a | 4b | ||
5a | 5b | ||
6a | 6b | ||
7a | 7b | ||
8a | 8b |
Pin | Function | Pin | Function |
---|---|---|---|
1a | 1b | ||
2a | 2b | ||
3a | 3b | ||
4a | 4b | ||
5a | 5b | ||
6a | 6b | ||
7a | 7b | ||
8a | 8b | ||
9a | 9b | ||
10a | 10b | ||
11a | 11b | ||
12a | 12b | ||
13a | 13b | ||
14a | 14b | ||
15a | 15b | ||
16a | 16b | ||
17a | 17b | ||
18a | 18b | ||
19a | 19b | ||
20a | 20b | ||
21a | 21b | ||
22a | 22b | ||
23a | 23b | ||
24a | 24b | ||
25a | 25b |
Pin | Function | Pin | Function |
---|---|---|---|
1a | 1b | ||
2a | 2b | ||
3a | 3b | ||
4a | 4b | ||
5a | 5b | ||
6a | 6b | ||
7a | 7b | ||
8a | 8b | ||
9a | 9b | ||
10a | 10b | ||
11a | 11b | ||
12a | 12b | ||
13a | 13b |
Pin | Function | Pin | Function |
---|---|---|---|
1a | +5 V DC | 1a | +5 V DC |
2a | 0 V | 2b | 0 V |
3a | 3b | ||
4a | 4b | ||
5a | 5b | ||
6a | 6b | ||
7a | 7b | ||
8a | 8b |
Jumpers:
- RESET: Close to reset
- RAMSIZE: 8 HB or 32 KB/128 KB
Memory Map
Start | End | Function |
---|---|---|
8000H | 27FFFH (128 KB) FFFFH (32 KB) A000H (8 KB) |
RAM |
0000H | 7FFFH | 32 KB ROM |
Port | Function |
---|---|
90H | Switch Input |
88H | DAC Output |
87H | ADC Input 8 |
86H | ADC Input 7 |
85H | ADC Input 6 |
84H | ADC Input 5 |
83H | ADC Input 4 |
82H | ADC Input 3 |
81H | ADC Input 2 |
80H | ADC Input 1 |
Circuit Description
TBC
Software
TBC