chuck yerkes wrote:

Ryan Wheeler wrote:

Jim Rojas wrote:


I have a special programmer used for security systems. The problem
with it is that it based on 1980's RAM technology. Does anyone
know if it is possible to modify the unit to accept modern memory
sticks?

The base unit only holds 512K, which I believe is a memory chip.
The expansion port that gives you another 512K using Epson MIXMOS
RAM Card. I would like to utilize either port for a memory stick,
thus eliminating problems storing client information.

A simple 16MB memory stick would be like putting a dragster
engine in a VW Bug...

Can anyone help?

Thank you in advance.

Jim Rojas


1980's ? the memory will be static ram (SRAM). (my guess)
16meg memorys will most likely not work.

Um, static RAM was (is) expensive. I'm looking into an Apple //
and it's rows of dynamic RAM chips. Same with the (1982?) Tandy
CoCo and the (1978) TRS-80 board I've got here.

You COULD replace it with static RAM and then you don't have to
worry about refresh rates, but no matter, you're going to be INTIMATE
with what each wire on that expansion slot is.

Does it have enough address lines? does it have a chip select wired
out that you need to attach to or do you need to decode that yourself?
the SPEED of the chip (response wise) what you likely DONT need to
deal with. A static RAM that yawns for a 100Mhz chip will twiddle
its thumbs for an 8MHz chip. (that's part of why I'd avoid dynamic
RAM - you don't want to deal with refresh strobes that are coming too
slow to keep you're stuff alive.

And no, your "1980's" technology will not have enough address wires to
reach the whole memory. ("80's is a little vague as we went from Z80s
and 6502s and their 64k max to 386s, 68040s, SPARCs, MIPS with far
MORE addressing).

But a 512K static RAM chip is findable.

This is not a task for a novice.

have a look at this idea:

http://www.maxim-ic.com/appnotes.cfm/appnote_number/535

all static ram