CS MK 1 memory errors
Tobias Hain
I own a Cyberstorm MK I 68o4o/4o. For this card exist two
different Ram modules. The difference are small ICs on
the later one, which should amplify the signal (AFAIK)
to avoid problems when putting a lot of PS/2 modules on
it.
I encounter memory errors, meaning I can produce two
different files "file1" and "file2" with the command
"copy ram:file1 ram:file2".
Unfortunately the errors occurs very seldem and are
hard to reproduce. I was getting distrustful when
installing Linux and my system crashed quite often.
This is due to the more aggressive memory usage of
Linux and I tried to reproduce it under AmigaOS. It
took me some time, but now I'm able to reproduce the
error under AmigaOS.
What I tried / found out / excluded so far:
- the power supply is powerful enough (e.g. the HD and
CD-Rom are in a separate SCSI-Tower with its own PS)
- the more PS/2 modules I put on the ram module the
more frequent I get ram errors (testet from 4 MB (1
module) - 32 MB (2 modules) )
- the errors are independent of the two versions of
ram modules for the MK I
- the ram is 100% okay (e.g. tested same procedure in a
different Amiga with the same ram and didn't get any
errors)
- yes, the errors disappear using spray to cool some
devices down. But the Amiga is *not* too hot. Un-
fortunately I'm not able to locate the responsible
device, as the cooling spray doesn't allow precize
application. I always cool several devices and can't
tell whether the error disappeared, because my mem-
mory modules have better electrical properties when
cold down or whether the memory controller on the
MK I motherboard worked flawless when cold down.
- on the MK I are jumpers allowing slower memory
timings. Using slower settings didn't help.
I assume that this is a bug in the construction of
at least some of the produced MK I series. Does some-
body know what exactly was changed in the ram design
of the MK II that has a slower ram interface (and was
said to be more compatible).
Thankful for any help
__
/oby
Marcel DeVoe
I have the MKII but have never seen the MK I but have read about it.
I personally think from your description that your problem on the MKI
board itself.
Which is probably why you now "own" it. ;)
I think when you add the extra memory simms you are not only loading up
the board but also blocking part of the air flow with them thus doubling
the problem.
On trick you might try to prove this is, since the chips on the CPU card
are SMD devices, you could try to bend the end of the straw on the coolant
spray can at an angle and reach under and spray on the "underside" of the
board. This should cool any surface mounted devices on it without cooling
the simms.
What? You didn't get a "straw" with your coolant spray can?
Well you better get one. ;)
You say that the Amiga is not overly hot but with an 040 the CPU card must
*certainly* be so. I'm not saying that the 040 itself is going bad from
overheating (although it could be) but that it is the main contributer of
heat on the CPU card.
You don't say what kind of cooling you have on the 040. When I got my
stock 3640 board it only had a heat sink on it. I don't know what a phase5
040 came with but I would bet if you got a better cooling system on it, a
heat sink AND fan combo with thermal grease between, that might help
alleviate some of your symptoms.
I have also read on this newsgroup of someone having a problem with
soldered connections on the CPU itself to the board of a phase5 card which
would cause a system crash after a time heating up. When he pushed on the
CPU a certain way the crashes would cease. He resoldered the pins and no
more crashes. But this is only from memory so don't take my word for it,
but is one more thing to consider.
--
Marcel J. DeVoe - mde...@shore.net - Team *AMIGA*
A4091scsi CV64 96 megs CDRW M1764-17" Catweasel FUSION/Emplant
A4000/060 CyberStorm MKII overclocked 66mhz - see "How to Overclock!"
and "DIY A4000 Tower for $45" @ http://www.shore.net/~mdevoe
Got an overclocking story to tell of /any/ kind?
Send it to me and I will post it to my "Overclocker's Web Page".