Bill,



    I have the TI TTL data book from that era which lists

both L123 and LS123 one-shots.  The timing formulas are a

little different, but the parts are very similar.  I am thinking

that you could probably use an LS123, and change the resistor

between Rext/Cext and VCC a little to get the same pulse width.

I can e-mail you the data sheet if you want.  It might be very hard

to find a 74L part these days. (Or not.  I haven't tried)



     Bob Grieb





--- billdeg@... wrote:



> Unfortunately no, it has to be the 74L123.

> bd

>

> > billdeg wrote:

> >> I am learning a lot about the Altair 680.  It appears that the

> memory

> >> is OK, but as you can see from the latest pictures...

> >>   http://www.vintagecomputer.net/MITS/680/pictures.html

> >> ...I am missing a chip, a 74L123.  Might anyone here have a spare

> lying

> >> around?

> >>

> >>

> > Bill,

> >

> >     Would a 74LS123 be a suitable replacement?

> > http://www.unicornelectronics.com/IC/74LS.html has them for 27

> cents.

> >

> > Cheers,

> >

> > Bryan

> >

> >

> >

> >

> >

> > Yahoo! Groups Links

> >

> >

> >

> >

>

>

>









________________________________________________________________________________\

____

Have a burning question?

Go to www.Answers.yahoo.com and get answers from real people who know.

billdeg@... wrote:

> Unfortunately no, it has to be the 74L123.

> bd

>

>

Bill,



According to a book I have - "Basic Electronics Theory" by Delton Horn -

the 74L uses a tenth of the power a standard TTL uses but gates at tenth

the speed while a 74LS uses a little more power then a low power TTL but

gates at the same speed as a standard TTL.

Wouldn't you be able to use something that switches faster then the part

you are replacing?



Cheers,



Bryan



>> billdeg wrote:

>>

>>> I am learning a lot about the Altair 680.  It appears that the memory

>>> is OK, but as you can see from the latest pictures...

>>>   http://www.vintagecomputer.net/MITS/680/pictures.html

>>> ...I am missing a chip, a 74L123.  Might anyone here have a spare lying

>>> around?

>>>

>>>

>>>

>> Bill,

>>

>>     Would a 74LS123 be a suitable replacement?

>> http://www.unicornelectronics.com/IC/74LS.html has them for 27 cents.

>>

>> Cheers,

>>

>> Bryan

>>

>>

>>

No, spews says it's not listed.  Besides, I did try from my work

address as well.   Can't get email to you either way.  Besides, most

blacklists immediately return an error so the sender knows what

the problem is and can fix it.  I just get no reply for 4 days, then

sendmail gives up.



Sorry, I've only got 74LS123 parts in my stockpile.



Bob





----- Original Message -----

From: <billdeg@...>

To: <midatlanticretro@yahoogroups.com>

Sent: Thursday, March 01, 2007 21:59 PM

Subject: Re: [midatlanticretro] Altair 680 Project Update





> Bob,

> We greylist/blacklist here, your IP address is in spews.org as a spammer.

> You should check this out.  If the problem persists, we can whitelist you

> to bypass the blacklist.

> Bill

>

>

>

>

> I might, but won't know until I get home around 8 PM.

>>

>> Does it need to be an "L" part or would an LS work?

>>

>> BTW, I can't seem to email you directly... it bounces back as

>> undeliverable

>> after a few days.

>>

>> Bob

>>

>>

>>   ----- Original Message -----

>>   From: billdeg

>>   To: midatlanticretro@yahoogroups.com

>>   Sent: Thursday, March 01, 2007 3:33 PM

>>   Subject: [midatlanticretro] Altair 680 Project Update

>>

>>

>>   I am learning a lot about the Altair 680. It appears that the memory

> is OK, but as you can see from the latest pictures...

>>   http://www.vintagecomputer.net/MITS/680/pictures.html

>>   ...I am missing a chip, a 74L123. Might anyone here have a spare lying

> around?

>>

>>   Bill

>>

>>

>>

>>

>

>

>

>

>

Bob,

Our logs shows that it was on blacklist for a time, probably not any

more.  Try again.

Bill



At 12:39 AM 3/2/2007 +0000, you wrote:

>No, spews says it's not listed.  Besides, I did try from my work

>address as well.   Can't get email to you either way.  Besides, most

>blacklists immediately return an error so the sender knows what

>the problem is and can fix it.  I just get no reply for 4 days, then

>sendmail gives up.

>

>Sorry, I've only got 74LS123 parts in my stockpile.

>

>Bob

>

>

>----- Original Message -----

>From: <billdeg@...>

>To: <midatlanticretro@yahoogroups.com>

>Sent: Thursday, March 01, 2007 21:59 PM

>Subject: Re: [midatlanticretro] Altair 680 Project Update

>

>

> > Bob,

> > We greylist/blacklist here, your IP address is in spews.org as a spammer.

> > You should check this out.  If the problem persists, we can whitelist you

> > to bypass the blacklist.

> > Bill

> >

> >

> >

> >

> > I might, but won't know until I get home around 8 PM.

> >>

> >> Does it need to be an "L" part or would an LS work?

> >>

> >> BTW, I can't seem to email you directly... it bounces back as

> >> undeliverable

> >> after a few days.

> >>

> >> Bob

> >>

> >>

> >>   ----- Original Message -----

> >>   From: billdeg

> >>   To: midatlanticretro@yahoogroups.com

> >>   Sent: Thursday, March 01, 2007 3:33 PM

> >>   Subject: [midatlanticretro] Altair 680 Project Update

> >>

> >>

> >>   I am learning a lot about the Altair 680. It appears that the memory

> > is OK, but as you can see from the latest pictures...

> >>   http://www.vintagecomputer.net/MITS/680/pictures.html

> >>   ...I am missing a chip, a 74L123. Might anyone here have a spare lying

> > around?

> >>

> >>   Bill

> >>

> >>

> >>

> >>

> >

> >

> >

> >

> >

>

>

>

>

>

>Yahoo! Groups Links

>

>

>

Bill,



    Looking at the photo showing the missing chip,

it appears that you may also be missing a few components

in the O/I section.  (or is that I/O? :-) )  I see a place

that looks like it had a transistor, and two pads that look

like a resistor was once there.  Maybe it's the difference

between 20 mA current loop and RS-232 or something.



    Nice pictures, BTW.



    Bob Grieb





--- billdeg <billdeg@...> wrote:



> I am learning a lot about the Altair 680.  It appears that the memory

>

> is OK, but as you can see from the latest pictures...

>   http://www.vintagecomputer.net/MITS/680/pictures.html

> ...I am missing a chip, a 74L123.  Might anyone here have a spare

> lying

> around?

>

> Bill

>

>









________________________________________________________________________________\

____

Don't pick lemons.

See all the new 2007 cars at Yahoo! Autos.

http://autos.yahoo.com/new_cars.html

http://www.mel.wisc.edu/



These guys claim to have some.  $1.78 each.

Not sure if they still do or what the shipping would be.



Bob Grieb





--- billdeg <billdeg@...> wrote:



> I am learning a lot about the Altair 680.  It appears that the memory

>

> is OK, but as you can see from the latest pictures...

>   http://www.vintagecomputer.net/MITS/680/pictures.html

> ...I am missing a chip, a 74L123.  Might anyone here have a spare

> lying

> around?

>

> Bill

>

>









________________________________________________________________________________\

____

Have a burning question?

Go to www.Answers.yahoo.com and get answers from real people who know.

Hey man, I don't know which documentation you guys are reading,

I suspected you had downloaded the 680b docs already.

How can the 74LS74 can be mistaken for a 74L123.at location L ?

Maybe thats on the 8800--I don't have that manual

I've been checking my original docs with all my notes from when I built

this back then.

My schematics are dated 5/4/76, rev 1-6X mainboard

I have a 680b too, which is what you have as best as I can tell.

I double checked my assembly docs and parts list too.

It also states the 74LS74 is only needed if you use a Baudot terminal.

I suppose your using a standard RS232 terminal,right ?

There's 3 different sets of parts for the I/O configuration.

It's on pg.16,29,30 of the assembly manual.

I scanned it in case nobody has it.

http://ragooman.home.comcast.net/computers_altair680.html



=Dan









[ My Corner of Cyberspace http://ragooman.home.comcast.net/ ]







billdeg wrote:

>

> I am learning a lot about the Altair 680. It appears that the memory

> is OK, but as you can see from the latest pictures...

> http://www.vintagecomputer.net/MITS/680/pictures.html

> <http://www.vintagecomputer.net/MITS/680/pictures.html>

> ...I am missing a chip, a 74L123. Might anyone here have a spare lying

> around?

>

> Bill

>

>

> ------------------------------------------------------------------------

>

> No virus found in this incoming message.

> Checked by AVG Free Edition.

> Version: 7.5.446 / Virus Database: 268.18.5/706 - Release Date: 2/28/2007 4:09

PM

>

Hey man, I don't know which documentation you guys are reading,
I suspected you had downloaded the 680b docs already.
How can the 74LS74 can be mistaken for a 74L123.at location L ?
Maybe thats on the 8800--I don't have that manual
I've been checking my original docs with all my notes from when I built
this back then.
My schematics are dated 5/4/76, rev 1-6X mainboard
I have a 680b too, which is what you have as best as I can tell.
I double checked my assembly docs and parts list too.
It also states the 74LS74 is only needed if you use a Baudot terminal.
I suppose your using a standard RS232 terminal,right ?
There's 3 different sets of parts for the I/O configuration.
It's on pg.16,29,30 of the assembly manual.
I scanned it in case nobody has it.
http://ragooman.home.comcast.net/computers_altair680.html

=Dan

I just got off the phone with Dan Yee of the University of Wisconsin

Medical Electronics Lab.  Shhhh! They are selling off their old chips,

parts, etc.  They used to support a PDP 8 and some other vintage systems,

now they only have the parts.



Here is what I just bought:



IC-DIGITAL 74L123  One Shot $1.78 (last one)

IC-DIGITAL 74LS109  JK-Type Flip Flop $1.18  (to fix my Processor Tech

Cassette board)



Here is a link to the inventory:

http://www.mel.wisc.edu/mel_sale.htm



Bill

Wow... it must have taken someone quite a bit of time to input all

that inventory.

It's quite a list.



73 de Ray



On Mar 2, 2007, at 1:27 PM, B. Degnan wrote:



> I just got off the phone with Dan Yee of the University of Wisconsin

> Medical Electronics Lab.  Shhhh! They are selling off their old chips,

> parts, etc.  They used to support a PDP 8 and some other vintage

> systems,

> now they only have the parts.

>

> Here is what I just bought:

>

> IC-DIGITAL 74L123  One Shot $1.78 (last one)

> IC-DIGITAL 74LS109  JK-Type Flip Flop $1.18  (to fix my Processor Tech

> Cassette board)

>

> Here is a link to the inventory:

> http://www.mel.wisc.edu/mel_sale.htm

>

> Bill

>

>

>

>

> ------------------------ Yahoo! Groups Sponsor --------------------

> ~-->

> Great things are happening at Yahoo! Groups.  See the new email

> design.

> http://us.click.yahoo.com/lOt0.A/hOaOAA/yQLSAA/S_NqlB/TM

> --------------------------------------------------------------------

> ~->

>

>

> Yahoo! Groups Links

>

>

>

     Look what Sanity Clause brought:



http://ripsaw.cac.psu.edu/~mloewen/Oldtech/IBM129/



     ... a model 129 keypunch.  It needs a minor overhaul, but it works.

Call it a gross indulgence, but I've always wanted one (or an 029).  :-)

Besides, my card reader was getting lonely.





Mike Loewen 		 mloewen@...

Old Technology http://ripsaw.cac.psu.edu/~mloewen/Oldtech/

There's an 029 waiting for us in the Princeton area, we just need strong

people to get it.



Tried with my father but no success.



-----Original Message-----

From: Mike Loewen [mailto:mloewen@...]

Sent: Tuesday, March 06, 2007 3:42 PM

To: midatlanticretro@yahoogroups.com

Subject: [midatlanticretro] New toy





     Look what Sanity Clause brought:



http://ripsaw.cac.psu.edu/~mloewen/Oldtech/IBM129/



     ... a model 129 keypunch.  It needs a minor overhaul, but it works.

Call it a gross indulgence, but I've always wanted one (or an 029).  :-)

Besides, my card reader was getting lonely.





Mike Loewen 		 mloewen@...

Old Technology http://ripsaw.cac.psu.edu/~mloewen/Oldtech/





------------------------ Yahoo! Groups Sponsor --------------------~-->

Yahoo! Groups gets a make over. See the new email design.

http://us.click.yahoo.com/hOt0.A/lOaOAA/yQLSAA/S_NqlB/TM

--------------------------------------------------------------------~->





Yahoo! Groups Links

On Tue, 6 Mar 2007, Evan Koblentz wrote:



> There's an 029 waiting for us in the Princeton area, we just need strong

> people to get it.

>

> Tried with my father but no success.



     Wasn't that an 026?  We had a couple of those in SAGE.  Definitely a

good addition to the museum.





Mike Loewen 		 mloewen@...

Old Technology http://ripsaw.cac.psu.edu/~mloewen/Oldtech/

Hmm, maybe it was.  I forget now.



-----Original Message-----

From: Mike Loewen [mailto:mloewen@...]

Sent: Tuesday, March 06, 2007 6:03 PM

To: midatlanticretro@yahoogroups.com

Subject: RE: [midatlanticretro] New toy



On Tue, 6 Mar 2007, Evan Koblentz wrote:



> There's an 029 waiting for us in the Princeton area, we just need

> strong people to get it.

>

> Tried with my father but no success.



     Wasn't that an 026?  We had a couple of those in SAGE.  Definitely a

good addition to the museum.





Mike Loewen 		 mloewen@...

Old Technology http://ripsaw.cac.psu.edu/~mloewen/Oldtech/







Yahoo! Groups Links

     An update on my IBM 129 keypunch...



     I replaced the main V-belt, which was severely cracked.  Installed a

new ribbon.  Oiled and greased lots of stuff.  Cleaned with rubber rollers

with Rubber Rejuvenator.  Aligned the upper card guide.  Removed a couple

of washers which were rattling around inside the keyboard.  Cleaned the

card path.



     The upshot?  It WORKS!  Feeds, punches, prints, stores program cards,

program control works.  I'm a happy camper.  :-)





Mike Loewen 		 mloewen@...

Old Technology http://ripsaw.cac.psu.edu/~mloewen/Oldtech/

excellent!

b

d



At 06:54 PM 3/13/2007 -0400, you wrote:



>     An update on my IBM 129 keypunch...

>

>     I replaced the main V-belt, which was severely cracked.  Installed a

>new ribbon.  Oiled and greased lots of stuff.  Cleaned with rubber rollers

>with Rubber Rejuvenator.  Aligned the upper card guide.  Removed a couple

>of washers which were rattling around inside the keyboard.  Cleaned the

>card path.

>

>     The upshot?  It WORKS!  Feeds, punches, prints, stores program cards,

>program control works.  I'm a happy camper.  :-)

>

>

>Mike Loewen                             mloewen@...

>Old Technology  http://ripsaw.cac.psu.edu/~mloewen/Oldtech/

--- In midatlanticretro@yahoogroups.com, Mike Loewen <mloewen@...> wrote:

>     An update on my IBM 129 keypunch...

>     I replaced the main V-belt, which was severely cracked ...

>     The upshot?  It WORKS!

> Feeds, punches, prints, stores program cards,

> program control works.  I'm a happy camper.  :-)



That's totally awesome!

I'd love to try it someday, for I only used IBM 029 keypunches (and a Decision

Data smart-one, one at a client). If the MARCH sorter could be restored to a

point where we could confidently demonstrate it at will, I'd love to make up a

small deck to demonstrate RADIX sort!



We got a donation of a small deck of blank cards, so I put them in the MARCH

keypunch.



-- Jeff3 Jonas

>>      An update on my IBM 129 keypunch...

>>      I replaced the main V-belt, which was severely cracked ...

>>      The upshot?  It WORKS!

>> Feeds, punches, prints, stores program cards,

>> program control works.  I'm a happy camper.  :-)

> That's totally awesome!

> I'd love to try it someday, for I only used IBM 029 keypunches (and a Decision

Data smart-one, one at a client). If the MARCH sorter could be restored to a

point where we could confidently demonstrate it at will, I'd love to make up a

small deck to demonstrate RADIX sort!

>

> We got a donation of a small deck of blank cards, so I put them in the MARCH

keypunch.

>

> -- Jeff3 Jonas



Jeff: You just replied to a message from March 13, 2007!  (Same subject

line as David's thread though.)

> Jeff: You just replied to a message from March 13, 2007!

> (Same subject line as David's thread though.)



Just keeping things really retro :-)

So much for my confidence in auto-threaded systems!

Didn't wait for xmas to open my new toy. It was a little big to go under

the tree anyway.



http://www.pdp8online.com/straight8/pdp8.shtml

> Didn't wait for xmas to open my new toy. It was a little big to go under the

tree anyway.

>

> http://www.pdp8online.com/straight8/pdp8.shtml



Congrats!!!  How did it come into your possession?



As you know ours is #1158, probably made in 66 or 67.  But now that you

have one, it's good practice for getting ours to work.   :-)

> Congrats!!!  How did it come into your possession?

>

Got an email asking if I wanted a PDP-8 about 13 months ago. Slowly

worked out details and it showed up Wednesday.



> As you know ours is #1158, probably made in 66 or 67.  But now that you

> have one, it's good practice for getting ours to work.   :-)

>

The core memory on yours is dated 43rd week of 1967. The core memory

serial number is 30707 so it looks like they were used into other

machines later. My core is 84 and the machine 184.



http://www.vintagecomputer.net/tcf_2008/digital_pdp8_sn1158_core-memory-stack-ID\

.JPG

On Fri, 24 Dec 2010, David Gesswein wrote:



> Didn't wait for xmas to open my new toy. It was a little big to go under

> the tree anyway.

>

> http://www.pdp8online.com/straight8/pdp8.shtml



     Outstanding!





Mike Loewen 		 mloewen@...

Old Technology       http://sturgeon.css.psu.edu/~mloewen/Oldtech/

That's wonderful news.  I look forward to hearing more about it.





Bill Degnan



-------- Original Message --------

> From: "Evan Koblentz" <evan@...>

> Sent: Friday, December 24, 2010 11:10 PM

> To: midatlanticretro@yahoogroups.com

> Subject: Re: [midatlanticretro] New toy

>

> > Didn't wait for xmas to open my new toy. It was a little big to go

under the tree anyway.

> >

> > http://www.pdp8online.com/straight8/pdp8.shtml

>

> Congrats!!!  How did it come into your possession?

>

> As you know ours is #1158, probably made in 66 or 67.  But now that you

> have one, it's good practice for getting ours to work.   :-)

>

>

>

>

> ------------------------------------

>

> Yahoo! Groups Links

>

>

>

I am speechless that is such a great "new toy"



I gotta say congrats. That is really really cool..



--- On Fri, 12/24/10, David Gesswein <djg@...> wrote:

Didn't wait for xmas to open my new toy. It was a little big to go under the

tree anyway.



http://www.pdp8online.com/straight8/pdp8.shtml