I just got word (thanks Shawn!) that an electronics shop in California
has MMD-2 boards, stripped of some parts, available for something like $10
or $15 each. I haven't seen them myself, so I can't vouch for them in
any way. If you are interested, contact Haltek Electronics:
1062 Linda Vista Ave.
Mountain View, CA
phone: (650) 969-0510
Please let me know when this info is no longer accurate, so I can remove it.
Of course, this is not at all exciting if you already own one...
Hey! E&L Instruments is still alive, and on the web!
Here's the URL: http://www.elinstruments.com/
The beginning of a short discussion about the MMD-1.
(Not the same thing, I know, but related.)
Assembly listing of the ROM from the MMD-1.
Also the beginning of another thread about the MMD-1 and 8080.
- 4K RAM addresses $0000..$0FFF
- ROM addresses $D800..$E7FF
- 256 bytes of RAM, ($FC00..$FCFF?)
- WE 0 - Write enable for addresses $0000..$03FF
- WE 1 - Write enable for addresses $0400..$07FF
- WE 2 - Write enable for addresses $0800..$0BFF
- WE 3 - Write enable for addresses $0C00..$0FFF
- SPARE - ???
- HEX OCT - choose display and entry to be in Hexadecimal or Octal
- PUP RESET - ???
- EXEC USER - update binary LED's with data entry? Or not?
(in either setting, outputs to ports 0,1,2 still show)
- Enter bytes on the keypad of hex digits
- Set MSByte of address by entering it on the keypad & pressing "HIGH".
- ... LSByte ... "LOW"
- Change contents of memory at the selected address by entering the new
value & pressing "STORE".
- Look at adjacent memory locations with "NEXT" and "PREV".
- Execute the program at the selected address by pressing "GO".
- BRL HI # - OFF disables BRL LO
- BRL LO #
- STEP #
- SRC HI # - source for COPY/DUMP - OFF disables "DUMP" function
- DES HI # - destination for COPY/DUMP
- LEN HI # - length for COPY/DUMP
- CLR TST ON - test if PROM is empty
- POP PRM ON - program a PROM
- DUP TST ON - test if PROM duplicated okay
- PROM 2708/2716
- MEM MAP RAM/ROM
- BAUD 110/150/300/600/1200
my classic computer web page
(remove all "x"s to get a valid address)