FPGA VAX update

[Allison]

>
>Subject: Re: FPGA VAX update
>   From: "Chuck Guzis" <cclist at sydex.com>
>   Date: Wed, 02 Nov 2005 16:13:45 -0800
>     To: cctalk at classiccmp.org
>
>On 11/2/2005 at 6:31 PM Allison wrote:
>
>>Valves are harder due to power, heat and most importantly size. A few
>>hundred
>>miniature duo-triodes will fill several racks.
>
>I used to buy old mil-surplus boards that each contained six wired-in
>subminiature (Raytheon CK something or the other) dual triodes--no sockets,
>the tubes were equipped with wire lead bases and were about the size of
>those suminiature tubes in the old Motorola Pixie radio.  At the time, I
>wasn't that interested in computers, but the triodes made for some great
>VHF circuits.

Ah 5899 5636 and 6111 come to mind. I have a bunch and have build radios
around them.

>What surprises me about the home-built computers from scratch is the lack
>of imagination when it comes to architecture.  Most are basically
>one-address-cum-accumulator designs.  It would seem that larger register
>files are much easier to build nowadays and would open up the door to some
>2 and 3-address designs.  

That would be an area where performance can be found with even simple 
instruction sets.

>I've always thought that 24 bits is a nice word size for a small computer.
>Divisible by 2, 3, 4, 6, 8 and 12 bits.  An instruction could use 6 bits
>for opcode and 3 register addresses out of a 64 register file...
>
>Variable word length, dataflow, all sorts of possibilities--why be limited
>by implementing something that resembles an already existing machine?

one word... SOFTWARE.

>But then why go to the trouble of wiring the thing up?  Write a
>simulator--it'll probably run faster anyway.

A friend suggested that sims are just software on a bloated wintel box.

Eh, nice for creating software for the iron.  Me, I'd rather fight with the
iron and have something that has heft and is real.


Allison