EPROM Compatibility Question

[Terry Martin]

Sandy wrote:
> 
> HELP - I have a EPROM question, and don't have the data books. Here's the
> problem. I'm trying to get this 68332 Board up, and the EPROM's that I
> purchased are Toshiba  TC571000AD's The board uses a 27C010A. Are these
> compatible. My programmer can program them just fine, but they don't seem
> to be working. They do check out as programed from the programmer, and the
> data in them looks good.
> 
> Help!
> 
> Sandy

Try a verify of the device data against the programmer several different
ways. Use the device limits against the entire programmer ram. I suspect
that the programmer loads at 0000h and if you don't set the device
offset it will start your device run address at 0000h. You may require
the start address of the device (offset) to tell the programmer start
loading the device from "####h". It may also be neccesary to tell the
programmer to stop at the device end, or it will continue to dump
redundant data until the device is full.

You could should also check your programmer's device support list. If it
doesn't support the device, it may recognize it as valid anyhow, and the
data ends up all screwed up.  

You could possibly go up to a 27C128. I don't have a criss-cross for the
device but using one with excess capacity normally shouldn't bug it. 

Oh yeah, it might sound stupid but it's easy to miss; make sure your
programmer is checking the programmed device data against the programmer
data. Start by filling the entire programmer ram with "empty" (FF), and
reload your data. I've been stumped on this one because the programmer
retained old data from soemthing else, and simply wrote the new stuff in
without clearing the remaining old stuff. 

Terry