7 Jan
2005
7 Jan
'05
3:19 a.m.
Hi
RTL is 3.6V. You could get by with CMOS but
not TTL, directly. Of course, you could run two
power rails. The signal levels of RTL and TTL are
somewhat compatable.
Dwight
From: "Cini, Richard"
<RCini(a)congressfinancial.com>
OK, this might sound like a stupid question, but being somewhat ignorant of
RTL logic in comparison to TTL and other designs, what, if anything, can be
substituted for RTL logic chips?
For example, if I wanted to build one of Don's devices and I wasn't
concerned with using "vintage" chips, could I do it "plug-and-play"
using
current TTL?
Rich
-----Original Message-----
From: cctalk-bounces(a)classiccmp.org
[mailto:cctalk-bounces@classiccmp.org]On Behalf Of Michael Holley
Sent: Friday, January 07, 2005 12:08 AM
To: cctalk(a)classiccmp.org
Subject: RTL Logic
I have acquired some Don Lancaster designs that use RTL logic and I am
looking for spare parts. The MC789 hex inverter is used in all of them and I
have 2 chips. Does anyone have a reasonable source for the MC789, I can get
all I want for $20 a chip.
I also have 2 MC799 buffers that are use in the Microlab. I have found two
each of these (MC725, MC778, MC785, MC792, MC853, MC855) that I will part
with.
SWTPC Digital Logic Microlab
http://www.swtpc.com/mholley/PopularElectronics/Apr1970/PE_Apr1970.htm
Early SWTPC keyboard
http://www.swtpc.com/mholley/PopularElectronics/Apr1974/PE_Apr1974.htm
I think that Don Lancaster's TIC TAC TOE machine from 1971 is a very clever
design. It uses 5 ICs and 60 diodes to play the game. I may build one.
http://www.swtpc.com/mholley/RadioElectronics/Dec1971/RE_Dec1971.htm
Michael Holley
www.swtpc.com/mholley
7 Jan
7 Jan
3:37 a.m.
3.6v? Are you joking or do you believe that? Way back when I worked a
little with RTL and always used 5v. On the other hand CMOS might work in
many cases.
Randy
----- Original Message -----
From: "Dwight K. Elvey" <dwight.elvey(a)amd.com>
To: <cctalk(a)classiccmp.org>
Sent: Friday, January 07, 2005 11:19 AM
Subject: RE: RTL Logic
Hi
RTL is 3.6V. You could get by with CMOS but
not TTL, directly. Of course, you could run two
power rails. The signal levels of RTL and TTL are
somewhat compatable.
Dwight
From: "Cini, Richard"
<RCini(a)congressfinancial.com>
OK, this might sound like a stupid question, but being somewhat ignorant
of
RTL logic in comparison to TTL and other designs, what, if anything, can
be
substituted for RTL logic chips?
For example, if I wanted to build one of Don's devices and I wasn't
concerned with using "vintage" chips, could I do it "plug-and-play"
using
current TTL?
Rich
-----Original Message-----
From: cctalk-bounces(a)classiccmp.org
[mailto:cctalk-bounces@classiccmp.org]On Behalf Of Michael Holley
Sent: Friday, January 07, 2005 12:08 AM
To: cctalk(a)classiccmp.org
Subject: RTL Logic
I have acquired some Don Lancaster designs that use RTL logic and I am
looking for spare parts. The MC789 hex inverter is used in all of them and
I
have 2 chips. Does anyone have a reasonable source for the MC789, I can
get
all I want for $20 a chip.
I also have 2 MC799 buffers that are use in the Microlab. I have found two
each of these (MC725, MC778, MC785, MC792, MC853, MC855) that I will part
with.
SWTPC Digital Logic Microlab
http://www.swtpc.com/mholley/PopularElectronics/Apr1970/PE_Apr1970.htm
Early SWTPC keyboard
http://www.swtpc.com/mholley/PopularElectronics/Apr1974/PE_Apr1974.htm
I think that Don Lancaster's TIC TAC TOE machine from 1971 is a very
clever
design. It uses 5 ICs and 60 diodes to play the game. I may build one.
http://www.swtpc.com/mholley/RadioElectronics/Dec1971/RE_Dec1971.htm
Michael Holley
www.swtpc.com/mholley
3:46 a.m.
On Fri, 7 Jan 2005, Randy McLaughlin wrote:
3.6v? Are you joking or do you believe that? Way
back when I worked a
little with RTL and always used 5v. On the other hand CMOS might work in
many cases.
Randy
At least the Fairchild 9xx series of RTL used 3.6V.
(I still have a few 914's in my junk box)
RTL tends to be more VCC range tolerant than TTL.
Peter Wallace
4:04 a.m.
Shows me why I would love to see more online docs, more than 30 year old
memories fade for me.
Randy
----- Original Message -----
From: "Peter C. Wallace" <pcw(a)mesanet.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk(a)classiccmp.org>
Sent: Friday, January 07, 2005 11:46 AM
Subject: Re: RTL Logic
On Fri, 7 Jan 2005, Randy McLaughlin wrote:
3.6v? Are you joking or do you believe that?
Way back when I worked a
little with RTL and always used 5v. On the other hand CMOS might work in
many cases.
Randy
At least the Fairchild 9xx series of RTL used 3.6V.
(I still have a few 914's in my junk box)
RTL tends to be more VCC range tolerant than TTL.
Peter Wallace
4:02 a.m.
>>>> "Randy" == Randy McLaughlin
<randy(a)s100-manuals.com> writes:
Randy> 3.6v? Are you joking or do you believe that? Way back when I
Randy> worked a little with RTL and always used 5v.
Well, then you were lucky. (I have an old keyboard with RTL logic in
it, and the documentation say that it *can* be powered with 5 volt
power though at some risk of damage to the chips if you're unlucky.)
But Dwight is right, the data sheet says Vcc is 3.6 volts.
paul
5:40 a.m.
On Fri, 7 Jan 2005, Randy McLaughlin wrote:
3.6v? Are you joking or do you believe that? Way
back when I worked a
little with RTL and always used 5v. On the other hand CMOS might work in
many cases.
3.6V, but also:
+4.5V and -2V
+3.3 to +5V
+12V - +20V
-30V (MOS)
And that's just the first few data sheets in my very meager
collection.
7289
days inactive
7289
days old
5 comments
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