phupp@warwick.ac.uk (S Millington) (05/16/91)
I have found a possible compatibility problem with 1meg CHIP RAM on an
A500 fitted with a SPIRIT FAT TRAPPER ram board. The major symptom of this is
that the screen memory gets trashed under pull down menus when using intuition
based software. Newer games just make the computer "fade" to sleep.
The A500 was supplied with an 8372A fitted as standard, which was latter
enabled when an A501[The Origional!] was fitted. At this stage there were
no unexpected problems. More recently the A501 has been changed for a
Spirit Fat Trapper. Only now have the problems started to appear. The fat
trapper *DOES* have the 1meg chip ram PAL, s/n 4468, as specified in the
manual.
*EVERY* ram test program I have tried says that all the ram is OK
(chip and slow). Swapping the ram chips to different sockets has also been
tried, so it is unlikely to be a badly seated chip on the expansion board. The
chips on the motherboard are soldered, and therefore not swopped around:-)
The problems mentioned above do not happen on all software which makes me
unwilling to believe that is a major ram problem. Also the offending software
has been tested on a B2000 with a similar memory configuration and works
perfectly.
The system is:
A500 [8372A enabled] KS1.3
Spirit Fat Trapper Memory board [1meg ram fitted]
no external drives,etc
1 MEG CHIP RAM
0.5 MEG SLOW RAM - software enabled
The slow ram has to be enabled in software because the ram board causes a
"yellow boot" when it is told that KS1.3 is fitted, however if it is told that
KS1.2 is fitted it is OK, but this means that the slow ram is not
autoconfiging. [This is generaly an advantage due to the high number of games
that don't like slow/fast ram.]
The screen memory trashing is occasionally reduced by enabling the
slow ram.
One other symptom may be that the clock "disappeared" for about 2 weeks a
while ago - I'm not completely convinced that this is conected to these
problems.
The other confirmed symptom is that programs, games and serious, that
require a FULL 1meg of memory will not run on just 1meg of chip ram on the
A500, but WILL run on just 1meg of chip ram on the B2000! The B2000 is
KS/WB1.3.2 with an A2091 & A2088, which I would have thought would have
soaked up some memory for themselves - leaving even less for programs!
I would appreciate any help anyone could give me on this, as I don't want
to spend a month without any ram while I get a replacement from the supplier.
Believe it or not, I hope this is a compatability problem:-) Thanks in
advance.
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* Stuart Millington * "A Mind Is A Terrible Thing, Remember *
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