19 Jun
2014
19 Jun
'14
8:41 a.m.
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.