S100 PROM boards

[Dave Dunfield]

>>            With my two new machines I want to get a PROM monitor in them so
>>I can start really playing around with them. I have a single Vector RAM/PROM
>>III board, which uses 2704 or 2708 EPROMS. Most of the chips I have are 2732
>>or larger.
>>
>>            Before I go slogging through the manual to try to hammer a 4k
>>chip into a 1k socket, does anyone have any experience making this mod?
>>Alternatively, can someone recommend a good general PROM board that can use
>>larger EPROMS (programming feature not necessary).
>
>
>I'd build a board, it's fairly trivial.  Compared to the mods needed to 
>make a 2708 board take 2732s.  There is one easy way and thats to make 
>a header that takes the 2732 and maps the Data/Address/CS-/OE- pins 
>to the 2708 socket along with power and ground.  That will allow only 
>using 1k of the 2732 but that may be all you need.  the upside is one
>2732 can hole 4 1k programs and it's easier to program than 2708.

I agree with Allison, It's pretty easy to make a board.

Another option might be to make a daughter card which not only adapts the
2732 (or bigger) to the 2708 socket, but also takes a couple of extra
address lines and the select via taps to other locations on the board.

I don't have the schematic for this particular board in front of me,
however if it takes multiple 2708 EPROMs, the there likely is a decoder
which has a select generated by the board address range, and the next
few higher address lines to determine which EPROM device to enable.

By ignoring the chip select at the 2708 socket, and taking it from the
input to the decoder along with a couple of extra address lines, then
you can fit a larger device on a small daughter board without having to
hack the board (worst you will have to do is tack onto some signals).

I have a couple of different 8080 monitors that might be of use to you.

I have a <500 byte very basic monitor, which has the advantage that it
requires NO RAM (not even for a stack) - it provides basic dump/edit
memory, execute and loop read/write commands (handy for hardware
debugging).

I also have a 3.5K full 8080 debug monitor, which features memory
dump/disassemble/edit/fill/copy, register dump/edit, In/Out, execute,
single-step, breakpoints and a bunch of other goodies.

I'll be happy to send them to you. I can also give you LOTS of other
original 8080 CODE (Disk OS, BASIC, editor, assembler etc.)

Regards,
Dave
-- 
dave04a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Collector of vintage computing equipment:
                http://www.parse.com/~ddunfield/museum/index.html