Re: TWGS vs ZipGS (was Re: WOLF3D fot A2 GS)

[supertimer@aol.com (Supertimer)]

spec@vax2.concordia.ca (Mitchell Spector) wrote:

>In article supertimer@aol.com (Supertimer) writes...
>
>>spec@vax2.concordia.ca (Mitchell Spector) wrote:
>>
>>>ZipGS is clearly the superior product.
>>>
>>>TransWarp GS
>>>------------
>>>- Original firmware does not support beyond 6.25 MHz
>>
>>The great majority of TWGS came with 7Mhz CPUs and the
>>ROM v1.5 firmware that supports speeds up to 15Mhz.
>
>    I was just simply stating a fact. There ARE boards out there
>with the original ROM (v1.4) and cannot be upgraded unless you
>replace the daughterboard. There is no such thing as old Zip GS
>that cannot be upgraded, so this definitely applies as a con.

That's not true, Mitch....there were pre version 1.1 Zip boards
that conflicted with RamFASTs and other cards.  Zip offered
an upgrade for these earlier boards, but some are still out there.
They are as rare as the 6Mhz ROM v1.4 TWGS you have.

>    My own TWGS has the original ROM, making my board virtually
>worthless to me except for parts. The only way to get a new ROM
>is to order a complete daughterboard replacement, and that costs
>more than a complete TWGS. In fact, I discovered it is cheaper
>to just purchase a new TWGS than ordering replacement parts and
>that is what I'm about to do.

The fact that you have a rare crippled version of the TWGS has
biased you against the card.  Most TWGS cards are not like
this just like most Zip GS cards are not the crippled v1.0 model.

>>>- Not DMA compatible
>>
>>Says who?
>
>    Um, this is common knowledge. The TWGS does not properly (or
>at all for that matter) support DMA, which was just _one_ of the
>things that made the ZipGS more attractive.

TWGS works fine with my DMA Apple HS SCSI card and I got
an email from a RamFAST user who says it can DMA to RamFAST
too.  Must be the fact you have a rare crippled version of the
RamFAST.  You know that ZipGS v1.0 did not properly support
DMA either.

>>>- Compatibility issues with certain software and hardware
>>
>>Not!  It is just as transparent as the Zip GS.
>
>    Well this is my observation, at least with the original ROM
>firmware. When I try and run ProTERM 3.1, it displays a garbled
>screen and tells me some obscure ProDOS error. If I remove the
>TWGS, this problem disappears (and it certainly does not occur
>with my ZipGS). I can just imagine what other oddities it may
>cause with software.

You have a rare crippled version of the TWGS.  My TWGS
works fine with ProTERM.  On the other hand, I distinctly
recall reading about v1.0 Zip GS having problems running 8-bit
software.  InCider/A+ wrote that the fix was to solder a wire
bridging the two solder pads diagnally to the corners of the board.

>    With hardware, there's the DMA issue again. It does not get
>along very well with a RamFAST SCSI or memory cards which try
>and do DMA. My ZipGS, OTOH, works beautifully with DMA enabled.

The "normal" TWGS units work fine with DMA enabled.

>>>- Poor stability (newer CPU cable and cooling may fix this though)
>>
>>Quite stable.
>
>    Not mine. It crashes and locks after the system has been on
>a couple of minutes. Mind you, I do have one of the cards with
>the original CPU ribbon cable (no black dot on it) and this may
>very well be the cause.

You have a bad TWGS.  Someone with the rare crippled version
of the Zip GS, v1.0, would feel like you do about the TWGS.

>>>- Requires newer GAL chips for high speeds with pre-1993 65C816's
>>
>>And who is using such pre-1993 chips anymore?  The current
>>65C816s don't need any such GAL replacements.
>
>    Once again, I am just stating a fact. The ZipGS does not
>need chips replaced depending upon the manufacturing date of
>the 65C816 plugged in. All my 65C816's--with the exception
>of the -14 rated one in my ZipGS--are all pre-1989 chips as 
>it happens.

This is also probably the reason why the TWGS is a bit faster
per clock speed....the ZipGS has logic to slow down the card
at more occasions because it assumes the older 65C816.  The
TWGS took a chance and maximized performance.  Those who
wanted to go to higher clock speeds with existing CPUs could
swap for GALs that would slow down the card on more occasions,
similar to what the ZipGS does.  Now with the newer 65C816,
the ZipGS is locked into the old logic.  With the TWGS, we
just don't get the replacement "slowdown" GALs that were
once needed....and enjoy slightly greater speed with the better
CPU chips.  On the ZipGS, it does not matter that the CPU
chips have gotten better....the Zip is stuck slowing down the
CPU as though it were the old ones.....

>>>- Simple to upgrade (daughterboard and oscillator socketed)
>>>- ROM based software to adjust speed/configure of card
>>>- More efficient caching method, runs slightly faster
>>
>>Yup.  You can still get a blank daughterboard that has
>>skinny SRAM sockets.
>
>    The daughterboard replacements are only available through
>SHH Systems overseas, and their prices are quite expensive if
>you ask me. Fortunately, as you mentioned, this is only an
>optional upgrade.

The blank daughterboard is much less expensive (but I
never needed it....the original chips pull 12.5Mhz quite
well).