Re: RamFast/TWGS

[supertimer@aol.com (Supertimer)]

CBS <jsmith66@hotmail.com> wrote:

>Notice below information appears to be ONLY for the Revision C of the
>RamFast.

You are absolutely correct.  After posting a bunch of replies
where I erroneously claimed that the info was current for
Rev D RamFAST, I saw my error in the RamFAST manual.

Furthermore, Tony obviously does NOT have a 2B GAL
(see his web site) and yet his Rev D RamFAST works with
DMA with his TWGS.

Sorry about the error (again)...

>quoted from page 24 of the  printed RamFASTmanual:
>"
>*************************************
>IIgs with a TWGS and a RamFAST/SCSI RevC
>
>The top one
>should be TWGS 1A and the one below it should be TWGS-2B.  If this chip
>is labeled TWGS-2A  you will need to contact AE to obtain a
>replacement(TWGS-2B).  The RamFast/SCSI will not function in your
>computer until you get this replacement part.  At the time this was
>printed, the replacement was free of charge (****SEE NOTE*****).
>*************************************
>"
>NOTE: applied engineering is gone and you can't get a replacement 2B
>chip anymore

Several more things: I've discovered that the 2B GAL
is apparently another trap that slows down the operation
of the flawed 65C816 so that it can work with the way the
RamFAST did DMA.

The Rev D RamFAST mostly fixed this problem except
that certain of the old flawed 65C816 chips were pushed
really close to the edge.  These TWGS units would
still fail with even the Rev D RamFAST.  BUT, in this
case even the 2B GAL often did not help.  The 65C816
needed to be replaced with a good 14Mhz 65C816.

Also this generates another question: now that the 14Mhz
65C816 no longer has the flaws that were "gotten around"
by the 2B GAL, it is very likely that with the 14Mhz unit,
even the Rev C RamFAST will NOT need the 2B GAL.
To answer this hypothesis requires Rev C RamFAST
plus TWGS users to be surveyed.

Just think...if WDC got their act together in the first place
and had a GOOD 65C816, the TWGS would most likely
have needed NO GALs and the ZipGS would also
have gone a bit faster.