Re: Mousecard HW question...

[waynes@intergate.ca (Wayne Stewart)]

Randall Frank wote
> Hello,
> 	I just picked up a mouse card (670-0030-C, 1983) and
> poped it into my //e, slot 4.  Everything that looks for the
> mouse came back saying there was no mouse.  So, I quick listed
> the ROM at $C400 and found that there was no ROM there (random
> bytes that changed with each read).  So, I think I may have a
> defective card (yes, it does have all the chips on it).  I notice
> that there are two pads on the card labeled 'X1' and 'X2' any
> chance I need to open one up (X1 is closed) or solder one 
> closed (X2 is open)?  I have tried other slots and get the sam
> results, no ROM.
> 	Any other diagnostics someone might suggest?  It looks
> like a pretty simple card...
> 
> Thanks.

X1 and X2 have to do with which chip is in the socket directly above 
them. If you have the chip labeled 341-0285 then X1 is closed and X2 
open. If chip has a sticker on it labeled 341-0269 or a clear window 
then X1 is open and X2 closed.

It's possible the EPROM is suffering from bit rot. EPROMs do lose 
their programming over time. If you have access to an EPROM burner 
or get a shop to burn one you can download the image from my website. 
It's a 2716 EPROM
http://homepage.mac.com/waynes

	Wayne