Re: Looking for GS-RAM+ GSPLD1A.1 Chip

[Jerry <SNIPawanderin@yahoSNIPo.ca>]

"Henry S. Courbis" <apl2research(a.t.)comcast.net> wrote:

> Hey Willi.
> 
>>    OK, I found one of them.  But it has only 3 MB of RAM chips in it
>> plus a note on it that says it passes the AE memory test OK with the 3
>> MB but if additional banks of RAM chips are added then 1 of the 24
>> chips comprising the first 3 MB, that previously tested OK, shows up
>> as bad.  VERY odd...
> 
> I believe the issue with the GAL is only with RAM above 4 Megs.  Anything
> under 4 megs is fully DMA compliant.  Anything over needs some voodoo to
> make it work correctly.  Let me know if you find something different
> though.
> 
> From what I can tell it's due to the fact that the ROM0/1 had the FPI and
> the ROM3 has the CYA.  Both IC's were designed differently I believe.
> Probably due to the fact that the Main RAM is of different sizes in the
> two machines.

Just to be clear, <= 4 MB RAM works fine with DMA.  That is how my card is
configured.  >= 5MB does not.  And you cannot have  4 MB < x < 5 MB. with
the GSRAM Plus  :)

-- 
--  Jerry