[comp.sys.amiga.tech] Dave Haynie addressing mod

kowal@stsci.EDU (Charles Kowal) (12/06/89)

I have just installed the Cris Eriving ram expansion into my A1000.  The
memory seems to be OK.  Addmem puts it all in fast memory, and AVAIL knows
that its there.  But when I actually try to use the memory, the machine
crashes!  It may be that the "Workbench 1.2 hardware fix" is not working,
because I have Kickstart in ROM, (via Kickstart Eliminator).  I am using
Workbench 1.3 and ARP 1.3 .

I heard of something called "Dave Haynie's addressing mod", which evidently
puts the news memory at address C00000, instead of 080000.  This might
solve my problem, but where can I get information about this modification?

Can anybody help with info about the mod, or other helpful hints?  I have
not yet tried to rip out the "Workbench 1.2 hardware fix", and use the
software fix instead.

Many thanks.

-----------------------------------------------------------------------
Charles Kowal
Internet:  KOWAL@stsci.EDU
SPAN: SCIVAX::KOWAL
-----------------------------------------------------------------------

daveh@cbmvax.UUCP (Dave Haynie) (12/07/89)

in article <986@stsci.edu>, kowal@stsci.EDU (Charles Kowal) says:
> Keywords: Cris Erving

> I have just installed the Cris Eriving ram expansion into my A1000.  The
> memory seems to be OK.  Addmem puts it all in fast memory, and AVAIL knows
> that its there.  But when I actually try to use the memory, the machine
> crashes!  

Sure sounds like flakey memory to me.  Have you run any memory tests on it?
It's pretty easy to mess up that Chris Erving memory hack -- I had one in use
for 1/2 a year before it started getting flakey and I noticed one pin on one
chip hadn't been soldered.  Of course, some folks say doing that kind of hack
at 4AM is my problem...

The other thing to watch out for is how that memory is first handled.  If you
use Chris's original mods, you get the memory at $080000, and the system thinks
it's chip memory.  If you don't somehow de-link it before adding it back in as
fast memory, there's going to be trouble.  That's not a problem if you did the
floppy disk light hack as well.

> I heard of something called "Dave Haynie's addressing mod", which evidently
> puts the news memory at address C00000, instead of 080000.  This might
> solve my problem, but where can I get information about this modification?

It's not going to make your flakey RAM good, but it will make for a better 
system once everything's working right.  What that trick does is hack the 
WCS daughterboard to map the second 512k at $C00000, just like on an A2000.
If you don't have a daughterboard anymore, that's not going to be much
use.  

Also, unfortunately, I wrote that hack up back in '85 or so, and haven't
been able to find a copy of it for the last couple years.  It consists of
a text description for the fix, and an IFF file with the schematics.  I
had originally uploaded this to Compuserve; for all I know, it's still
there.  One word of caution -- the original text description has a bug in
it, though the schematic is correct.  The original was up for less than a
week, but it seems to have made it's way around the world in that time.
The revised version mentions this.  In any case, if you have the schematic,
which you should since that's the way I intended it to be distributed, 
there's no problem -- the schematic was always correct.  Also, the hack
was done on a "Rev 3" daughterboard.  Some folks say it won't work on the
"Rev A" board; I haven't verified that one way or another, as I was never
able to locate a Rev A schematic.

> Charles Kowal
-- 
Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests"
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                    Too much of everything is just enough