22 May
2003
22 May
'03
3:46 p.m.
From: "ben franchuk"
<bfranchuk(a)jetnet.ab.ca>
David Comley wrote:
Hi
All make the assumption that you must make 8 bit/16bit
or, in your case, 20 bit. One can make a 1 bit alu that
can have data width controlled by instruction. It may
not be fast at math but much processor time is consumed
just looking at true/false. If your model doesn't require
passing data through the alu for mem/mem and mem/io moves,
a single bitter makes sense.
( My Nicolet is a 20 bit machine. )
Dwight
Since you mention it, I had been thinking about
designing and building a processor from scratch from
TTL devices. I am slowly accumulating TTL chips as I
come across them at hamfests and things. Perhaps it's
time to put pencil to paper.
Of course I could take the NASA Apollo Guidance
Computer approach and build everything welded-cordwood
style out of NOR gates.
Nope that used lots of REAL ( expensive ) TTL.
The neat part of that was the CORE memory used.
Any how a real TTL computer is about 4+ large
logic cards. Control card, alu card, memory card
and serial I/O card. The mother board is bus
and front pannel logic.
I am doing a 20 bit CPU with about 125 chips total
in the computer and front panel. About 50?
more chips for memory and serial i/o.
http://www.jetnet.ab.ca/users/bfranchuk/ldp/ldp1.html
Ben.
22 May
22 May
4:11 p.m.
Dwight K. Elvey wrote:
Hi
All make the assumption that you must make 8 bit/16bit
or, in your case, 20 bit. One can make a 1 bit alu that
can have data width controlled by instruction. It may
not be fast at math but much processor time is consumed
just looking at true/false. If your model doesn't require
passing data through the alu for mem/mem and mem/io moves,
a single bitter makes sense.
( My Nicolet is a 20 bit machine. )
Darn! All the good computer names are taken. :)
Do you have any more information?
Dwight
Some day I would like to see a DECIMAL computer in
TLL or FPGA like the early decimal machines.
Ben.
7:03 p.m.
On Thu, 22 May 2003, Dwight K. Elvey wrote:
I have considered making a 1 bit stack oriented machine with 4 bit
instructions, long and short jumps and memory reference are done by pushing
the target address a bit at a time onto the pointer stack, then issuing the
jump or memory ref inst (that looks at the 1 bit pointer stack depthwise)...
Peter Wallace
From: "ben
franchuk" <bfranchuk(a)jetnet.ab.ca>
David Comley wrote:
Hi
All make the assumption that you must make 8 bit/16bit
or, in your case, 20 bit. One can make a 1 bit alu that
can have data width controlled by instruction. It may
not be fast at math but much processor time is consumed
just looking at true/false. If your model doesn't require
passing data through the alu for mem/mem and mem/io moves,
a single bitter makes sense.
( My Nicolet is a 20 bit machine. )
Dwight
Since you mention it, I had been thinking about
designing and building a processor from scratch from
TTL devices. I am slowly accumulating TTL chips as I
come across them at hamfests and things. Perhaps it's
time to put pencil to paper.
Of course I could take the NASA Apollo Guidance
Computer approach and build everything welded-cordwood
style out of NOR gates.
Nope that used lots of REAL ( expensive ) TTL.
The neat part of that was the CORE memory used.
Any how a real TTL computer is about 4+ large
logic cards. Control card, alu card, memory card
and serial I/O card. The mother board is bus
and front pannel logic.
I am doing a 20 bit CPU with about 125 chips total
in the computer and front panel. About 50?
more chips for memory and serial i/o.
http://www.jetnet.ab.ca/users/bfranchuk/ldp/ldp1.html
Ben.
24 May
24 May
12:49 p.m.
[...]
This may not reduce the IC count that much!. I've recently been looking
at the HP9810-series calculators, and the processor in there is a bit
serial unit. There are 4 cards of around 20 chips each for the processor
(control, data path, clock, I/O interface) and another 2 or 3 cards,
again 20 chips each, for the mrmory interface. Which is easily comparable
to a full-parallel 16 bit processor.
-tony
I am doing a 20
bit CPU with about 125 chips total
in the computer and front panel. About 50?
more chips for memory and serial i/o.
http://www.jetnet.ab.ca/users/bfranchuk/ldp/ldp1.html
Ben.
Hi
All make the assumption that you must make 8 bit/16bit
or, in your case, 20 bit. One can make a 1 bit alu that
can have data width controlled by instruction. It may
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days inactive
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3 comments
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ard＠p850ug1.demon.co.uk -
bfranchuk＠jetnet.ab.ca -
dwightk.elvey＠amd.com -
pcw＠mesanet.com