Re: RamFast/TWGS

[CBS <jsmith66@hotmail.com>]

I didn't know anyone made errors in regards to the TWGS and RamFAST.  I just
thought that people would like to see what it says in the manual.

Supertimer wrote:

> 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.