Re: AE GS-RAM Plus compatibility?

["AMart79196@gmail.com" <AMart79196@gmail.com>]

On Apr 8, 1:45 am, Mitchell Spector <mitch...@hotmail.com> wrote:
>     Just received an Applied Engineering GS-RAM Plus memory
> card in the mail last week and have some questions about it.
>
> First some details...
>
> - Revision-D board, manufactured mid-1989
> - Has "GSPLD1A-Q" and "GSPLD2A-Q" GALs
> - I fully populated it to 6 MB (using 1MBx1 DRAMs pulled from a 386)
>
>     Interestingly enough, despite the mention of these GALs being
> only compatible with the ROM 01 firmware, the card appears to
> function just _fine_ in my ROM 3. I ran the AE diagnostic from an
> old AW 2 Expander disk I had from years ago, and Bit Banger, yet
> neither detected any errors. It also booted into the Finder desktop
> with several system extensions loaded. Is there some specific glitch
> it has on the ROM 3?
>
>     I'm curious about DMA compatibility. I have a RamFAST-D in the
> same system with DMA enabled. From what I recall, most AE RAM
> cards were infamous for claiming to be DMA compatible--yet not.
> The RamFAST manual is a little vague (only talks about the Rev A
> GS-RAM Plus, and then goes on to discuss the non-Plus card in detail).
>
>     How can I be sure the DRAMs follow CAS before RAS addressing?
> I allowed Bit Banger at least one entire pass (took a good hour or two)
> and nothing was reported. I also created a 6 MB+ RAM Disk and
> copied files from the hardisk, which also seemed to go over well.
>
>     I'm a little weary of both DMA and ROM 3 compatibility here but
> though I'd check with what others here have to say.
>
> Mitchell Spector

I have the gs-ram card, not the plus, but have had both, and yes, both
have a logic chip that is rom specific.
Now, i he earlier gs-ram card, not only was the logic chip different
(Different cause it acted wierd because of the difference in ram
between rom01 and 03 on the motherboard) so, in order for it to
recognize the other "extra" area of ram on the motherboard in a rom03,
you would need to change that chip.

Another issue that I found when testing both these cards is the delay
timing chip, namely the DS1000 chip.  This chip is on the regular gs-
ram card, but not in the gs-ram Plus card as the plus came out later
with better design.  This delay chip in the gs-ram card would have to
be changed in order for the card to operate properly.  Usually it's a
simple change of changing it from a ds1000-100 to a ds1000-125 or to a
ds1000-150.

The compatibility of the gs-ram plus card should and does run better
then its older regular card. (better design)

The only thing I would say if you were to run it on a rom03 is to get
the rom03 logic chip.  Reactive computers sells the gal chips.  Check
to make sure that all of the ram that you are supposed to have is
showing up including all of the on-board motherboard ram as well.
Check in GS/OS.
Your card is a good card and should work well.  Just try to make sure
you get the right chip in there unless you have the right chip and you
don't even realize.
Hopefully Henry from Reactive legacy computers can comment more on
this.
Good luck