Amiga 3000 zip ram problem

[zipper]

Take the chips away and look again.

[agr]

Take the chips away and look again.

I did it and googled for: Amiga Oktagon 2008 zip orientation
and found this: http://brain-plasticity.safe-install.com/  :whack:
and then I RTFM of the Oktagon in german :rtfm:
and found that I mounted the chips in the wrong orientation :madashell:

I fliped the chips and everything is ok.
> cpu nodatacache
> checkmem times 1000
... still running without error on the first half 8Mb.
Those chips are very resistant (also the Oktagon 2008...) !

Now for the A3k mb zip sockets, I did put the chips with pin 1 toward the caps, on the left when looking at sockets from the from of the A3k. Is that ok ?

[SpeedGeek]

Now for the A3k mb zip sockets, I did put the chips with pin 1 toward the caps, on the left when looking at sockets from the from of the A3k. Is that ok ?

Yes, thats correct. Bank 0 is from U850-U857. Now you need to find out why they don't work in the Zip sockets. If you have a PLCC extractor tool you could try removing Ramsey and reinstalling it. Also, it would be easy to do a continuity test from the Zip sockets to the Ramsey socket after the chip was pulled.

[agr]

Hello Amiga fans,

After 15 years, I post where did this go and what is the problem now.

I don't remember when, but my A3000 was fine with 2M chip + 16M fast zip RAM. I think the problem was solved by setting some jumper in the correct position.

And now, recently I flushed some Zorro cards around. At some point everything worked including +8M zip on my Oktagon 2008 and a SCSIknife on it. Then I removed the Oktagon to attach the SCSIknife to it, reinserted the card and the 16M zip disappeared.

I've seen another topic here on this forum: 'Amiga 3000 fastram suddenly disappeared' https://forum.amiga.org/index.php?topic=74971.0

So as suggested I used ziptest. It shows faults on U850, U858 all the way up to U875. If I swap those zip with U854 .. U879, the result is the same.

Can anyone help me to solve this issue ? Should I ask in the other topic ?

Thank you

[Castellen]

Does the fast memory work normally again if you remove all of the Zorro expansions?

I gather you've got 32 x 1Mbit ZIPs fitted to the A3000.  Are you saying that ZIPtest indicates that the first three 4MB blocks of fast memory is not working, but the last 4MB is showing as good?  Please post the entire test output from ZIPtest here as it's not obvious what's possibly good or bad, or what aspect of the test fails.


If you briefly pull the _FAIL line low, does the fast memory then appear normally afterwards?  You can do this by briefly linking U190 (real time clock IC) pin 2 to ground (the metal chassis) with the system running, which will force a hardware reset and initialise the fast memory controller (U890) to the correct power-up state.


Failing that, it may be worthwhile collecting more clues using DiagROM and using the 'Slow scan of 16MB fastmem-areas' to see what's going on.  Again, post the test result here.