RE: 9010A, Not sure what this means...

Thanks all. If anyone cares, a bad 9114 can exhibit this behaviour. I
tested various other address spaces (ROM sigs, other RAM areas), and
they tested fine. Replaced the lower nibble (this particuler 9114), and
the problem went away. Of course there are now new issues... But this is
solved. Thanks.

JB

--James Bright
www.QuarterArcade.com
Restored Arcade Games for your Home
 

> -----Original Message-----
> From: owner-techtoolslist@www.flippers.com
> [mailto:owner-techtoolslist@www.flippers.com] On Behalf Of
> John Robertson
> Sent: Saturday, April 19, 2003 8:14 PM
> To: techtoolslist@flippers.com
> Subject: Re: 9010A, Not sure what this means...
>
>
> RAM DCD means RAM ADDRESS DECODE. Thus the external
> addressing or internal
> decoding of the RAM is defective. Try using the WALK test for
> putting data
> in the RAM (I think it's that one) that will sequentially
> increment the
> data bit one byte at a time. Then do a read of that...
>
> John :-#)#
>
> At 05:44 PM 19/04/2003 -0400, James S. Bright wrote:
>
>
>
> >Working on a Centipede (6502 based).
> >
> >RAM test (Short or Long) on RAM that I think is good, I get "RAM DCD
> >ERR @ 0000 BIT 0". I'm not sure what this means. I've tested
> the buffer
> >chips (data and address) and they appear to be okay. When I
> run custom
> >tests (reading and writing AA/55), the RAM seems okay. Can anyone
> >elaborate on this error message? The manual didn't really
> help out. I'm
> >not exactly sure what to do next with this board.
> >
> >(This board doesn't play blind, and nothing appears on monitor.)
> >
> >TIA.
> >
> >JB
> >
> >--James Bright
> >www.QuarterArcade.com
> >Restored Arcade Games for your Home
>
Received on Sat Apr 19 19:05:08 2003