Re: Transwarp II photos posted online

[R.Kiefer.SPAM@gmx.de (Ralf Kiefer)]

Marcus wrote:

> He once told me that there were rumors or announcements of a
> 6502-based chess computer clocked at an - at the time -
> unbelievable 60 Mhz.

In 1988 we had the 68020 @20MHz, the first transputers running at 15MHz,
Intel's 80286 @20MHz, but 60MHz processors? IMHO 60MHz were senseless at
this time because of RAM access. 50nsec were fast, very fast in 1988.
Standard DRAM had an access time of 100nsec or 120nsec.

The design of the 6502 is synchronous. And we called the 6502 the first
RISC chip ;-)  


> The only way, I guess. When did WD bring their fast CMOS
> versions to the market? In the 90ies?

AFAIR I bought a 65802 @4MHz and tried to switch to 16bit with the AEs
Transwarp in 1987. In 1990 I got a data sheet which describes the family
of 6502 based controllers from Mitsubishi. The fastest controller chips
were running @ 12 MHz.


> Hmmm...why not the usual 128KB in a IIe? Any idea?

64kB + 64kB + 16kB (mirrored ROM).


> What purpose had the Cypress RAM chips on the top card?
> Separate zeropage and / or stack?

I don't know.


> How many bytes did your driver program use? (weird question,
> I know...)

Nearly 20 years ago ...  I don't know exactly. The driver was integrated
within the UCSD BIOS including optimized driver for text output,
keyboard, "beep" (interrupt driven :-) ), and printer (including spooler
in background, feels like multi-tasking ;-) ). But I didn't used the
standard way. BIOS and p-code interpreter were optimized (CMOS code and
a bit more in handling some tables). 

My first ram disk driver did not fill up the space for slot ROM (<
$0100).


> I guess that's a fair price for that kind of equipment - especially
> considering the development effort and low sales numbers.

I think that my card was the first accelerator (@12,5MHz, CMOS
instruction set) for use in a //e because I did a little bit debugging
within the special //e-hardware test in ROM. Probably it was also the
last. But I don't know. 


> By the way: A great read, Ralf!

Thanks, Ralf