1 Nov
2001
1 Nov
'01
12:30 p.m.
Those parts were never cheap!
You can also use 74289s for the '189s. The '382s are an improved version
of the '182. A note, if you can tolerate a slower ALU you can omit the
'382s
and just use ripple carry.
A sub for 74189s is some of the byte wide cache rams from an old 386/486
PC
as the faster ones were faster than the TTL 74189! You dont have to use
the full
space of the cache ram though having it would make afor an interesting
register array.
Allison
-----Original Message-----
From: Ben Franchuk <bfranchuk(a)jetnet.ab.ca>
To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org>
Date: Thursday, November 01, 2001 8:28 PM
Subject: Re: classiccmp-digest V1 #761
Somebody wrote
> >
> > While I agree that there are a lot of rack-mount random TTL junkies
here,
to
> some of
us, S-100 and things like that are "big iron" as well. =)
>
Hey some of like TTL, too bad you can't get 7400's for 5 cents each
anymore.
I have a great idea for a great LS computer but no 74LS189's or
74LS382's
exist cheap. Ben Franchuk.
--
Standard Disclaimer : 97% speculation 2% bad grammar 1% facts.
"Pre-historic Cpu's" http://www.jetnet.ab.ca/users/bfranchuk
Now with schematics. 
1 Nov
1 Nov
10:17 a.m.
ajp166 wrote:
Those parts were never cheap!
You can also use 74289s for the '189s. The '382s are an improved version
of the '182. A note, if you can tolerate a slower ALU you can omit the
'382s
and just use ripple carry.
If the 74289's are the non inverting 16x4 rams I would use them. I plan
to use 74ls382's (the ripple carry alu's).
A sub for 74189s is some of the byte wide cache rams
from an old 386/486
PC as the faster ones were faster than the TTL 74189! You dont have to use
the full space of the cache ram though having it would make afor an interesting
register array.
Can't do that for three reasons
1) I am use a 16 x 12 ram ( 3 chips ) on two boards for a 8 x 24
register array.
2) I am using the 486 cache chips as main memory in my FPGA prototype
32k x 12 bits.:)
3) This was a TTL design on paper of what a computer designed in the
early 1980's
could have been like. That rules out 2901 bit slices.
Allison
As it stands today I have a FPGA ( pat
pat pat ) that is configured to
have a similar
layout as the ttl design and this lets me play around with the
configuration. Mind you a
larger TTL CPU with lights and switches is more impressive. If you like
lights
and switches here is a neat link http://www.angelfire.com/scifi/B205/
'to the Bat Cave'
Ben Franchuk.
--
Standard Disclaimer : 97% speculation 2% bad grammar 1% facts.
"Pre-historic Cpu's" http://www.jetnet.ab.ca/users/bfranchuk
Now with schematics.
2 Nov
2 Nov
2:02 a.m.
The '289's are inverting, though tristate, just like the '189's. TI made
a '219
which was a noninverting tristate version of this same sort and pinout. ISTR
that there was yet another part, albeit not of the normal 74xxx sort, that was a
non-inverting version as well, but I can't, for the life of me, rememberit
(senior moment). These days, it's both cheaper and easier (faster, too) to use
a CMOS ram of considerably larger size.
Dick
----- Original Message -----
From: "Ben Franchuk" <bfranchuk(a)jetnet.ab.ca>
To: <classiccmp(a)classiccmp.org>
Sent: Thursday, November 01, 2001 5:17 PM
Subject: Re: classiccmp-digest V1 #761
ajp166 wrote:
interesting
Those parts were never cheap!
You can also use 74289s for the '189s. The '382s are an improved version
of the '182. A note, if you can tolerate a slower ALU you can omit the
'382s
and just use ripple carry.
If the 74289's are the non inverting 16x4 rams I would use them. I plan
to use 74ls382's (the ripple carry alu's).
> A sub for 74189s is some of the byte wide cache rams from an old 386/486
> PC as the faster ones were faster than the TTL 74189! You dont have to use
> the full space of the cache ram though having it would make afor an
register
array.
Can't do that for three reasons
1) I am use a 16 x 12 ram ( 3 chips ) on two boards for a 8 x 24
register array.
2) I am using the 486 cache chips as main memory in my FPGA prototype
32k x 12 bits.:)
3) This was a TTL design on paper of what a computer designed in the
early 1980's
could have been like. That rules out 2901 bit slices.
Allison
As it stands today I have a FPGA (
pat pat pat ) that is configured to
have a similar
layout as the ttl design and this lets me play around with the
configuration. Mind you a
larger TTL CPU with lights and switches is more impressive. If you like
lights
and switches here is a neat link http://www.angelfire.com/scifi/B205/
'to the Bat Cave'
Ben Franchuk.
--
Standard Disclaimer : 97% speculation 2% bad grammar 1% facts.
"Pre-historic Cpu's" http://www.jetnet.ab.ca/users/bfranchuk
Now with schematics.
8451
days inactive
8452
days old
2 comments
3 participants
participants (3)
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ajp166＠bellatlantic.net -
bfranchuk＠jetnet.ab.ca -
edick＠idcomm.com