2 May
2016
2 May
'16
11:07 a.m.
I did a bit of searching in the fall for an 8881 (to fix a busted HALT
instruction on a PDP8a). I concluded the 7439 is a pin-for-pin replacement
- I can't claim all credit for this, it's probably known by a few people
here. My notes say the 8881 will handle 30mA loads. The 7401 will handle
16mA, while the 7439 will handle 80mA.
Cheers!
b
On Mon, May 2, 2016 at 10:04 AM, Mattis Lind <mattislind at gmail.com> wrote:
The following
chips have been used by DEC to interface to the QBUS, and
I have seen many of the above chips (e.g. 8641's) used there too, so I
think chips seen on one bus could be used on the other:
Drivers:
7439 - Various - Quad NAND
Transceivers:
2908 - AMD - Quad latching transceiver with tri-state output
I _believe_ the following chips are also usable as UNIBUS/QBUS interface
chips, but I'm not sure if I've seen one used there:
Transceivers:
8836 - National Semi - Quad NOR
8838 - National Semi - Quad transceiver (aka Signetics N8T38)
Quite a zoo!
DEC also used the DEC DC005 for the data and address lines on QBUS cards.
The Signetics code is C2324N
/Mattis
Noel