Subject: Re: FPGA VAX update
From: "Chuck Guzis" <cclist at sydex.com>
Date: Wed, 02 Nov 2005 12:38:24 -0800
To: cctalk at
classiccmp.org
On 11/2/2005 at 2:55 PM Allison wrote:
Ego a 16bit machine September 1985. There was
another article whose
focus was microprogramming vs sequential machine control and that used
the TOY1 archetecture. There were others described in TCJ Dave Brooks
simplex III comes to mind. There are others.
Hmmm, my recollection is of an 8-bit machine pre-1985. I recall that it
was benchmarked against a 4MHz Z80A.
Not in byte or KB. Though there was an 8080 in 2900 form that was faster
than a real 8080.
My first attempt at building a semiconductor computer
was back in the late
1960's. Using RTL (no DIPs, just TO-86 flat packs), I managed to get a
12-bit ALU and accumulator done before I lost interest. I recall using a
lot of diodes to save on logic costs. I think I still have a couple of
the Fairchild 8-bit (1x8) addressable latch in a TO-100 package that were
going to form the basis of my register file. I believe it required a 7v
clock.
Sounds like some of the old PMOS stuff.
The nicest one I've done in TTL was a Harvard machine 8bit instructions
and 4bit data path. Not fast nor exotic though I wasn't trying for speed
it was likely limited the most by the 2716 eproms and 2112 mods rams. It
was practical in that it was a fairly rich instruction set. Harvard
machines can really simplify the data paths.
Anyone remember the Moto mw RTL
"experimenter's pack" that was sold back
then? That's when electronics companies still thought that appealing to
the hobbyist was worthwhile...
Cheers,
Chuck
Still have bits of the mW RTL from moto and also their ECL bits as well.
Did a lot of playing with those parts back when.
Allison