2 Apr
2007
2 Apr
'07
2:50 p.m.
Has anyone here pondered a 32-bit CPU in the spirit of the Magic-1? How
much harder would that be?
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
2 Apr
2 Apr
5:06 p.m.
I've thought about it. I actually entered half the schematics for the
Magic-1 into my schematic program. I was going to produce some PCBs for it
for a kit. I ended up giving up because I needed to spend time on the
Altair effort.
A goal of mine would probably be a TTL 8080 or completely a
transistorized (as in pbysical little black dots : ) ) 8080. The idea
behind that is it could be an extension to the Altair kit...
I have thought about a 32 bit CPU built like the Magic 1, and in fact drew
up the schematic for the ALU. I thought it would be fun to build a
computer using parts available in 1975 that was capable of decoding an
MP3. For speed designed a schematic for a 32x32 combinatorial
multiplier. :) I think I estimated it would draw 5A (just the
multiplier)... ; )
And no, it would not be the same if it were in an FPGA. : )
The 8080/transistor computer would have an LED for every transistor. Can
you imagine how cool it would be to single step that thing? : )
Grant
Has anyone here pondered a 32-bit CPU in the spirit of
the Magic-1? How
much harder would that be?
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
7:34 p.m.
On Mon, 2 Apr 2007, Grant Stockly wrote:
I've thought about it. I actually entered half
the schematics for the
Magic-1 into my schematic program. I was going to produce some PCBs for it
for a kit. I ended up giving up because I needed to spend time on the
Altair effort.
Nifty! I entered the ALU and part of the control board entered into
gschem with the same intent. Perhaps we could collaborate on that later
on. I made some alterations to allow use of a bog-standard VME chassis.
A goal of mine would probably be a TTL 8080 or
completely a
transistorized (as in pbysical little black dots : ) ) 8080. The idea
behind that is it could be an extension to the Altair kit...
On one of the pages linked from the homebrewcpu.org page is a project that
uses surface-mount transistors on what amount to tiny flipchips. If
you're insane enough to try a discrete 8080, go with that approach.
I have thought about a 32 bit CPU built like the Magic
1, and in fact drew
up the schematic for the ALU. I thought it would be fun to build a
computer using parts available in 1975 that was capable of decoding an
MP3. For speed designed a schematic for a 32x32 combinatorial
multiplier. :) I think I estimated it would draw 5A (just the
multiplier)... ; )
At that rate, the complete machine might demand 20 amps or more.
And no, it would not be the same if it were in an
FPGA. : )
Of course!
The 8080/transistor computer would have an LED for
every transistor. Can
you imagine how cool it would be to single step that thing? : )
At least I'd like to have LED displays for each bus, each flag, and each
register.
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
11:49 p.m.
Nifty! I entered the ALU and part of the control board
entered into
gschem with the same intent. Perhaps we could collaborate on that later
on. I made some alterations to allow use of a bog-standard VME chassis.
Sure. I still don't quite understand everything about the user modes or
addressing. Its possible that it I understand it and just don't think it
could be that simple. : )
On one of the pages linked from the homebrewcpu.org
page is a project that
uses surface-mount transistors on what amount to tiny flipchips. If
you're insane enough to try a discrete 8080, go with that approach.
I saw that. If I were to do anything like that I would want it to be an
educational tool. And for people who want to build it for fun, art. The
thing needs to lay flat so it could hang on a wall.
Don't tell me you wouldn't want to hang CP/M on the wall... : )
At that rate, the complete machine might demand 20 amps
or more.
Sure. And with a 5MHz clock it would multiply at the speed of a 100MHz+
486. : )
At least I'd like to have LED displays for each
bus, each flag, and each
register.
In a little Altair 680 sized box!
Grant
9:15 p.m.
Grant Stockly wrote:
I've thought about it. I actually entered half
the schematics for the
Magic-1 into my schematic program. I was going to produce some PCBs for
it for a kit. I ended up giving up because I needed to spend time on
the Altair effort.
A goal of mine would probably be a TTL 8080 or completely a
transistorized (as in pbysical little black dots : ) ) 8080. The idea
behind that is it could be an extension to the Altair kit...
See Bitsavers, under AMD you have a 2901 version of the 8080.
The only hard work is the PCB and getting the software/microcode
compiled.
I have thought about a 32 bit CPU built like the Magic
1, and in fact
drew up the schematic for the ALU. I thought it would be fun to build a
computer using parts available in 1975 that was capable of decoding an
MP3. For speed designed a schematic for a 32x32 combinatorial
multiplier. :) I think I estimated it would draw 5A (just the
multiplier)... ; )
The 8080/transistor computer would have an LED for
every transistor.
Can you imagine how cool it would be to single step that thing? : )
A PDP-8 Style
computer you might be able to build.
OH - Heck ... Just mass produce HAL-9000 from 2001. It may be better
logic than TODAY's AI stuff.
Grant
11:50 p.m.
See Bitsavers, under AMD you have a 2901 version of the
8080.
The only hard work is the PCB and getting the software/microcode
compiled.
There is an AMD and signetics 8080 emulator on bitsavers. I'm not sure
which one is the best or fastest...
I think the AMD microcode was compiled. It came with a listing I think???
Grant
3 Apr
3 Apr
8:10 a.m.
On 2 Apr 2007 at 22:53, Brent Hilpert wrote:
Just rumour to me, but circa 1980 when I was doing
some software development
with the spanky new 68000, I was told that the 68000 had been prototyped
as (literally) a large wall of SSI/MSI logic.
I believe that was true of the 6809. Somewhere there was published
an interview (BYTE, probably) with a member of the design team where
he mentions this.
Cheers,
Chuck
11:45 a.m.
On 4/3/07, Chuck Guzis <cclist at sydex.com> wrote:
On 2 Apr 2007 at 22:53, Brent Hilpert wrote:
Well, that article is/was on-line. I saw it one month ago.
Cheers,
Just rumour to me, but circa 1980 when I was
doing some software
development
with the spanky new 68000, I was told that the
68000 had been prototyped
as (literally) a large wall of SSI/MSI logic.
I believe that was true of the 6809. Somewhere there was published
an interview (BYTE, probably) with a member of the design team where
he mentions this. Chuck
2 Apr
2 Apr
7:32 p.m.
On 2 Apr 2007 at 14:50, David Griffith wrote:
Has anyone here pondered a 32-bit CPU in the spirit of
the Magic-1? How
much harder would that be?
I'll guess that by this you mean a CPU with a 32-bit word size.
There are always FPGA designs, but I'll assume that you mean a CPU
built from TTL SSI/MSI.
Do you have a speed requirement? Designing one with a bit-serial ALU
might not be a bad approach not requiring a mountain of logic.
Cheers,
Chuck
6475
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9 comments
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participants (6)
-
bfranchuk＠jetnet.ab.ca -
cclist＠sydex.com -
dgriffi＠cs.csubak.edu -
grant＠stockly.com -
hilpert＠cs.ubc.ca -
vax9000＠gmail.com