Re: ROM chip test

[Rubywand <rubywand@swbell.net>]

bobryan9@my-deja.com writes ...
> 
> I have a ROM chip which appears to be bad.  When the board is plugged
> into slot 2 and I list $c200-$c2ff in the monitor, i get:
> 
> ldy ao
> ldy ao
> ldy ao
> brk
> brk
> ldy ao
> lda ao
> 
> lots of other crud.  This is the same as I get when I have no card in
> the slot.

      The code you list may be some kind of false RAM image which is produced
for an empty $C2xx address space.



> Can I stick the ROM chip on another board and test it out?
> A mouse card or disk II card, or another common apple II card?  I am
> thinking maybe it could be another part of the board that is bad.
>
> The ROM chip is on an Applied engineering ramfacter card.  Is there
> anyone with a ROM image from this board, and anyone who could burn one
> for me?
 ....

     Have no experience with a RamFactor card. If the card is plugged into a
IIgs, you may need to go to the Slots setting in the Control Panel and make
sure Slot 2 is set to "Your Card" in order to read any ROM code in the $C2xx
page.

     Something else to try (once you are sure the Slot card is being selected)
is reading $CFFF and, then, say, address $C200 and, then, listing starting at
$C800.

     The $CFFF read should turn OFF all $C800-$CFFF ROMs (on all Slot cards). 
The $C200 read should enable the Slot 2 $C800-$CFFF address space.



Rubywand