[comp.sys.amiga.hardware] more probs with 2630 and 2090a

chem194@canterbury.ac.nz (John Davis, chem dept, UoC NZ) (09/22/90)

>I just fitted a 2630 ( 68030 ) board in my 2000 over the weekend,
>and I've been experiencing problems with the hard-disk (40mb toshiba 
>ST-506 interface drive off a 2090a ) ever since.
> 
>It'll read fine, and small writes are ok too - but any largish write
>will result in a total crash ( typically to guru 03, 04 or 0b ).
>
>I've tried swapping in a different 2090a off a working 2500/30, and
>it got rid of the problem - and I noticed the working controller
>had the PROM at the rear top of the board ( U36 I think ) marked
>as xxxxx-03, wheras as the non-working board was marked xxxxx-02. 
>
>Unfortunately the owner of that board kind of wanted it back ... :-)
>
>There's meant to be a replacement HD controller on the way - but what
>I'm interested in are ....
> 
>  - what are the difference between the different revisions of the 2090a
>    and what does it affect - are there any links, trace cuts etc that should
>    be done to the 2090a when used with the 2630?
>
>  - what other main board alterations should be done for the 2000 when
>    fitting the 2630 ( my motherboard is labeled rev 4.4 ).
>
> ( the board just turned up , no docs on recommended board mods to be 
> done before fitting etc )
>
>We've tried getting info out of CBM New Zealand, but they either
>don't have it, or don't want to pass it on to the dealer I'm going 
>thru.
>
>Incidentally, the 2090a problem seems related to DMAing into the 32 bit
>ram on the 2630 - at least if I set the mask entry in the mountlist to
>0xfffff to restrict  dma into the 16 bit chip mem it's ok ( then again
>that could be due to the slowdown in writes this incurrs ), it's also
>okay under the 68000 ....
> 
>Any help much appreciated ...

Well, the new controller turned up, and in spite of having the exact
same PAL/ROM version numbers as the card that _did_ work, the new one
exhibits the exact same fault as the old one. I'm now totally stumped, and 
as CBM NZ ( an outfit who's idea of tech support seems to be an answering 
machine with a recording 'I dunno' repeating ad infinitum ) still can't 
come up with any  info on how to remedy the situation, it looks like the 
only alternative is going to be to try and convince them to ship a complete
replacement machine, that hopefully will work properly - then again, given their
record so far (2 out of 2 2500's non-functional on delivery) I don't
hold great hopes.
 
I'd still really like to here from anyone who either has info on what
(if any) mods should be done to the rev 4.4 motherboard before fitting
a 2630 (wherefore art thou CBM engineering ??), or has any ideas on what's
causing this (like the only boards in the machine are the 2630 and 2090a -
considering they're all CBM boards you'd expect them to work together).

As I said it seems to be related to LARGE writes only - does anyone have
any info on whether there _should_ be a maxtransfer specified for FFS 
on the 2090a ( again, all we got when we asked CBM NZ's 'tech support person'
this was a 'derrrr .. ummm ... I dunno' ).
 
Ahhh .. the joys of living on the wrong side of the planet, stuck with 
a large pile of _expensive_ hardware that just refuses to work together. 

Time to go find a really good bar methinks .....

-----------------------------------------------------------
| o  John Davis - CHEM194@canterbury.ac.nz               o |
| o  (Depart)mental Programmer,Chemistry Department      o |
| o  University of Canterbury, Christchurch, New Zealand o | 
| o                                                      o |
| o  co-sysop AmigaINFO BBS,1200/2400 baud CCITT,        o |
| o           24 hours a day, ph NZ +3-3371-531          o |