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 <mattisl...@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 > > >