19 Jun
2014
19 Jun
'14
9:18 a.m.
Hi all,
i have here a PDP8/E with a defective M8300 Mayjor Register board. The
problem is a DEC8271 shift register that is used for bit 0 - 3 in
program counter register.
Do anyone know a modern equivalent for the DEC8271?
Greeting to all readers
Marco
* Englisch - erkannt
* Englisch
* Deutsch
* Englisch
* Deutsch
<javascript:void(0);>
19 Jun
19 Jun
11:11 a.m.
On Thu, Jun 19, 2014 at 2:18 AM, Marco Rauhut <marco at familie-rauhut.eu>
wrote:
i have here a PDP8/E with a defective M8300 Mayjor
Register board. The
problem is a DEC8271 shift register that is used for bit 0 - 3 in program
counter register.
Do anyone know a modern equivalent for the DEC8271?
It's a Signetics 8271. The full Signetics part number is N8271B for
plastic package or N8271E for ceramic, or "S" prefix rather than "N"
for
-55C to +125C temperature range.
There is no "modern equivalent". The 74LS395A has similar functionality
except that it has a single clock input and a load/shift control, whereas
the 8271 has separate load and shift clocks. And the pinout is completely
different.
If you can't get an 8271, you could program a PAL to do the same thing,
though it's possible that the much higher speed of the PAL could cause
problems.
I wouldn't advise trying to substitute the Intel 8271.
noon
New subject: unsubscribe
----- Original Message -----
From: "Eric Smith" <spacewar at gmail.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Thursday, June 19, 2014 8:11 PM
Subject: Re: DEC8271 shift register
On Thu, Jun 19, 2014 at 2:18 AM, Marco Rauhut
<marco at familie-rauhut.eu>
wrote:
i have here a PDP8/E with a defective M8300
Mayjor Register board. The
problem is a DEC8271 shift register that is used for bit 0 - 3 in program
counter register.
Do anyone know a modern equivalent for the DEC8271?
It's a Signetics 8271. The full Signetics part number is N8271B for
plastic package or N8271E for ceramic, or "S" prefix rather than "N"
for
-55C to +125C temperature range.
There is no "modern equivalent". The 74LS395A has similar functionality
except that it has a single clock input and a load/shift control, whereas
the 8271 has separate load and shift clocks. And the pinout is completely
different.
If you can't get an 8271, you could program a PAL to do the same thing,
though it's possible that the much higher speed of the PAL could cause
problems.
I wouldn't advise trying to substitute the Intel 8271. 
4:41 p.m.
New subject: unsubscribe
this might be the right one
http://store.americanmicrosemiconductor.com/n8271b.html
On 6/19/14, Romanoz <romanoz at grapevine.com.au> wrote:
----- Original Message -----
From: "Eric Smith" <spacewar at gmail.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Thursday, June 19, 2014 8:11 PM
Subject: Re: DEC8271 shift register
On Thu, Jun 19, 2014 at 2:18 AM, Marco Rauhut
<marco at familie-rauhut.eu>
wrote:
i have here a PDP8/E with a defective M8300
Mayjor Register board. The
problem is a DEC8271 shift register that is used for bit 0 - 3 in
program
counter register.
Do anyone know a modern equivalent for the DEC8271?
It's a Signetics 8271. The full Signetics part number is N8271B for
plastic package or N8271E for ceramic, or "S" prefix rather than "N"
for
-55C to +125C temperature range.
There is no "modern equivalent". The 74LS395A has similar functionality
except that it has a single clock input and a load/shift control, whereas
the 8271 has separate load and shift clocks. And the pinout is
completely
different.
If you can't get an 8271, you could program a PAL to do the same thing,
though it's possible that the much higher speed of the PAL could cause
problems.
I wouldn't advise trying to substitute the Intel 8271. 
5:47 p.m.
On 19/06/2014 11:11, Eric Smith wrote:
On Thu, Jun 19, 2014 at 2:18 AM, Marco Rauhut
<marco at familie-rauhut.eu>
wrote:
> Do anyone know a modern equivalent for the DEC8271?
It's a Signetics 8271. The full Signetics part
number is N8271B for
plastic package or N8271E for ceramic, or "S" prefix rather than "N"
for
-55C to +125C temperature range.
There is no "modern equivalent".
As Eric wrote, there's no exact equivalent, let alone a pin-compatible
one. When I had that problem I borrowed one from another board, but you
might be able to make up a daughterboard. If you want to go that route,
at home I have the Signetics data book with that part in it and could
probably scan the relevant pages.
I wouldn't advise trying to substitute the Intel
8271.
It would be a bit of a squeeze getting all the pins in.
3:08 p.m.
From: Marco Rauhut: Thursday, June 19, 2014 1:18 AM
i have here a PDP8/E with a defective M8300 Mayjor
Register board. The
problem is a DEC8271 shift register that is used for bit 0 - 3 in
program counter register.
Do anyone know a modern equivalent for the DEC8271?
As Eric said, there doesn't seem to be an exact modern equivalent.
You could try eBay auction #161031743575 (no connection to the seller).
Vince
4:17 p.m.
Thanks to all!
I have Stolen One from an also dead Extended Memory Controller.
That is only a temporal Solution....
@Vince: I tried to connect you behause i'am interested in your 32k kit for pdp8. Do
have them. still availible?
Marco
Am 19.06.2014 um 16:08 schrieb Vincent Slyngstad
<vrs at msn.com>:
From: Marco Rauhut: Thursday, June 19, 2014 1:18 AM
i have here a PDP8/E with a defective M8300
Mayjor Register board. The problem is a DEC8271 shift register that is used for bit 0 - 3
in program counter register.
Do anyone know a modern equivalent for the DEC8271?
As Eric said, there doesn't seem to be an exact modern equivalent.
You could try eBay auction #161031743575 (no connection to the seller).
Vince
6:24 p.m.
New subject: Omnibus Memory (was Re: DEC8271 shift register)
From: Marco Rauhut: Thursday, June 19, 2014 8:17 AM
@Vince: I tried to connect you behause i'am
interested in your 32k kit for
pdp8. Do have them. still availible?
Yes. I ordered some extras, and still have about a dozen unsold kits.
The folks in the USA have gotten theirs, though I haven't heard from
anyone (except the folks who helped with the debug -- thanks again!)
about their experiences assembling or testing it.
Overseas shipments (except maybe one) seem to be still hung up
in customs in their various countries.
Marco, I'm not sure why your messages didn't reach me.
Vince
7:16 p.m.
New subject: Omnibus Memory (was Re: DEC8271 shift register)
Hello Vince,
i tried two times. Anyway...
Thanks for your Answer now!
I ordered two times measurement equipment in Canada and USA. And yes
they hung up in customs. But i could free them by paying tax.
How much is on kit, and how much do you think is shipping to Germany?
Best Regards
Marco
Am 19.06.2014 19:24, schrieb Vincent Slyngstad:
From: Marco Rauhut: Thursday, June 19, 2014 8:17 AM
* Englisch - erkannt
* Englisch
* Deutsch
* Englisch
* Deutsch
@Vince: I tried to connect you behause i'am
interested in your 32k
kit for pdp8. Do have them. still availible?
Yes. I ordered some extras, and still have about a dozen unsold kits.
The folks in the USA have gotten theirs, though I haven't heard from
anyone (except the folks who helped with the debug -- thanks again!)
about their experiences assembling or testing it.
Overseas shipments (except maybe one) seem to be still hung up
in customs in their various countries.
Marco, I'm not sure why your messages didn't reach me.
Vince
9:45 p.m.
New subject: Omnibus Memory (was Re: DEC8271 shift register)
From: Marco Rauhut: Thursday, June 19, 2014 11:16 AM
How much is on kit, and how much do you think is
shipping to Germany?
I sent you PayPal info off-list. Hopefully you will get it :-).
With the overseas shipping one unit is $115. (Which is actually a bit of a
deal, since the international shipping is more expensive than I thought.)
Vince
20 Jun
20 Jun
11:55 a.m.
New subject: Omnibus Memory (was Re: DEC8271 shift register)
Hi Vince,
i received your answer with the price. I reply to your direct mail.
Do your received my answer?
My frind(in Germany) told me that he also mailed to you with no
answer...
Best Regards
Marco
Am 2014-06-19 20:16, schrieb Marco Rauhut:
Hello Vince,
i tried two times. Anyway...
Thanks for your Answer now!
I ordered two times measurement equipment in Canada and USA. And yes
they hung up in customs. But i could free them by paying tax.
How much is on kit, and how much do you think is shipping to Germany?
Best Regards
Marco
Am 19.06.2014 19:24, schrieb Vincent Slyngstad:
From: Marco Rauhut: Thursday, June 19, 2014 8:17
AM
* Englisch - erkannt
* Englisch
* Deutsch
* Englisch
* Deutsch @Vince: I tried to connect you behause i'am
interested in your 32k
kit for pdp8. Do have them. still availible?
Yes. I ordered some extras, and still have about a dozen unsold kits.
The folks in the USA have gotten theirs, though I haven't heard from
anyone (except the folks who helped with the debug -- thanks again!)
about their experiences assembling or testing it.
Overseas shipments (except maybe one) seem to be still hung up
in customs in their various countries.
Marco, I'm not sure why your messages didn't reach me.
Vince
19 Jun
19 Jun
7:40 p.m.
New subject: Omnibus Memory (was Re: DEC8271 shift register)
On Thu, Jun 19, 2014 at 1:24 PM, Vincent Slyngstad <vrs at msn.com> wrote:
The folks in the USA have gotten theirs, though I
haven't heard from
anyone (except the folks who helped with the debug -- thanks again!)
about their experiences assembling or testing it.
I acknowledged receipt but it will be some time until I can assemble
mine. There are other projects fighting for the head of the queue,
and winning.
-ethan
9:42 p.m.
New subject: Omnibus Memory (was Re: DEC8271 shift register)
From: Ethan Dicks: Thursday, June 19, 2014 11:40 AM
I acknowledged receipt but it will be some time until
I can assemble
mine. There are other projects fighting for the head of the queue,
and winning.
Yep. Seems like everyone must be in the same boat.
Vince
6:34 p.m.
this might be the right one
http://store.americanmicrosemiconductor.com/n8271b.html
On 6/19/14, Marco Rauhut <marco at familie-rauhut.eu> wrote:
Thanks to all!
I have Stolen One from an also dead Extended Memory Controller.
That is only a temporal Solution....
@Vince: I tried to connect you behause i'am interested in your 32k kit for
pdp8. Do have them. still availible?
Marco
Am 19.06.2014 um 16:08 schrieb Vincent Slyngstad
<vrs at msn.com>:
From: Marco Rauhut: Thursday, June 19, 2014 1:18 AM
i have here a PDP8/E with a defective M8300
Mayjor Register board. The
problem is a DEC8271 shift register that is used for bit 0 - 3 in program
counter register.
Do anyone know a modern equivalent for the DEC8271?
As Eric said, there doesn't seem to be an exact modern equivalent.
You could try eBay auction #161031743575 (no connection to the seller).
Vince 
20 Jun
20 Jun
6:29 a.m.
From: Vincent Slyngstad <vrs at msn.com>
From: Marco Rauhut: Thursday, June 19, 2014 1:18 AM
A superficial examination of the data sheets suggests that the 74178 might
be a replacement, but I don't have time to compare the specs at the moment.
--Bill
i have here a PDP8/E with a defective M8300
Mayjor Register board. The
problem is a DEC8271 shift register that is used for bit 0 - 3 in
program counter register.
Do anyone know a modern? equivalent for the DEC8271?
As Eric said, there doesn't seem to be an exact modern equivalent.
You could try eBay auction #161031743575 (no connection to the seller).
9:56 a.m.
On Thu, Jun 19, 2014 at 11:29 PM, William Maddox <wmaddox at pacbell.net>
wrote:
A superficial examination of the data sheets suggests
that the 74178 might
be a replacement, but I don't have time to compare the specs at the moment.
You're on the right trail. It looks like the 74178 matches the 8270, and
the 74179 matches the 8271. The pinout and function table appear to
match. The 7417x parts are slightly faster and draw slightly more power.
I didn't look at those due to misleading information in the selection guide.
11:57 a.m.
Thank you for that information! I have a look to the 74179 and compare
it with the 8271 to.
Marco
Am 2014-06-20 10:56, schrieb Eric Smith:
On Thu, Jun 19, 2014 at 11:29 PM, William Maddox
<wmaddox at pacbell.net>
wrote:
A superficial examination of the data sheets
suggests that the 74178
might
be a replacement, but I don't have time to compare the specs at the
moment.
You're on the right trail. It looks like the 74178 matches the 8270,
and
the 74179 matches the 8271. The pinout and function table appear to
match. The 7417x parts are slightly faster and draw slightly more
power.
I didn't look at those due to misleading information in the selection
guide.
3623
days inactive
3624
days old
16 comments
8 participants
participants (8)
-
ethan.dicks＠gmail.com -
halarewich＠gmail.com -
marco＠familie-rauhut.eu -
peter.turnbull＠york.ac.uk -
romanoz＠grapevine.com.au -
spacewar＠gmail.com -
vrs＠msn.com -
wmaddox＠pacbell.net