[comp.sys.atari.st] EZ-Ram problems

a1532@mindlink.UUCP (Alan Wong) (03/17/90)

  I've recently upgraded my 520 ST to 2.5 megs with an EZ-RAM board and I've
had a few problems. The first 2 megs of memory (from address $0000 to $200000)
is fine, but I have problems with the 512 K bank at the end
of memory($20000-$27FFFF). When I do word-length or long-length reads from this
area, I sometimes get the wrong value back. With byte reads, this almost never
happens. Secondly, only the lower half of a word gets munged up on the read.
Has anyone else had problems like these and does anyone have a solution?

cmm1@cunixa.cc.columbia.edu (Christopher M Mauritz) (03/19/90)

In article <1329@mindlink.UUCP> a1532@mindlink.UUCP (Alan Wong) writes:
>
>  I've recently upgraded my 520 ST to 2.5 megs with an EZ-RAM board and I've
>had a few problems. The first 2 megs of memory (from address $0000 to $200000)
>is fine, but I have problems with the 512 K bank at the end
>of memory($20000-$27FFFF). When I do word-length or long-length reads from this
>area, I sometimes get the wrong value back. With byte reads, this almost never
>happens. Secondly, only the lower half of a word gets munged up on the read.
>Has anyone else had problems like these and does anyone have a solution?

Did you connect the extra power leads that are attached to the board to
the power supply?

At first, I blew this off and figured the bus could provide enough power
(WRONGO!) for the extra RAM, but you will get flaky results without them
connected.  I used to get intermittent errors until I connected the 
buggers.  Hope this helps.

Chris






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