Re: TransWarp GS ROM question

[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:
>> 
>>>    I'm about to acquire a ROM chip for my currently non-functional
>>>TransWarp GS board, incase I decide to repair and upgrade it some-
>>>time in the near future. The person with the 1.5 ROM claims unlike
>>>his 1.8 ROM, the board gets unstable above 10 MHz and causes problems 
>>>with ProTERM 3.1 at 7.8 MHz and above (apparently the 1.8 does not).
>> 
>>This person is absolutely wrong.  I and at least two other csa2
>>readers have NO such problems with 12.5Mhz TWGS units
>>possessing 1.5 ROMs.
>
>    That's certainly welcome news to hear.
>
>>Most likely, your friend had bad static RAM chips.  He or she
>>probably upgraded to a 32k cache at the same time as the
>>1.8 ROM upgrade.  It is not the ROM's fault.
>
>    That was my first guess. The only other possibility is that
>the EPROM's data has been corrupted in some way, but hopefully
>that won't turn out to be the case.

An EPROM, I've read (on csa2 of all places) typically has
its data degraded by 25% per decade.  Luckily, the EPROM
itself is fine.  All you need is to put it in an EPROM burner,
read the data, and write it back to the EPROM.  Refresh it.
Since EPROMs can undego 100 such reprogrammings, they
can physically carry the data for 1000 years.

>    Incidentally, are the SRAM's on a typical 8K daughterboard
>fast enough to support 10, 12 or 15 MHz?

Mine runs at 12.5Mhz using the standard 8k cache.

>>By the way, I seriously suggest that before you give your
>>2 TWGS units the 9th degree that you try replacing the
>>CPU chip.  In older TWGS units, the 65C816 were very
>>flaky because the old design was pushed to the limit.  You
>>keep saying how your Zip GS is better and all that.  Stop to
>>think about what is logically the most different...the Zip GS
>>has a redesigned 65C816.
>
>    Not a bad idea, how much does a 65C816-14 currently cost?
>(Is Alltech and WDC still the only source?)

Since you have a university account, just pretend you
are still a student or are an educator.  Then you can
buy one directly from WDC for $19 US.  Plus shipping
that comes out to $24 in the US.  For Canada, plan a little
more shipping.