This is interesting!
I have never seen a 2748 interfaced to a 8-bit duplex register board.  This
would take a special cable, quite different from my reader cable.
The HP tape reader board I've always seen connected to the photo tape
readers is P/N 02116-8002.  Its simply labelled "Tape Reader", and has
a two row of 11 DIP packages, 8 two-transistor data receivers, and a 7
transistor driver-receiver section for flag and control.
Because the HP processor has no need to send data to the reader, the more
complex and expensive 8 bit duplex register is overkill.  But the signal levels
may be correct, if you have the right version of the duplex register board...
The HP Tape Reader 02116-8002 board can only send the state of the control
bit to the 2748 (or 2847) reader.  It accepts 8 data bits on pins 1-4 and A-D,
which
is not compatible with the 8-bit duplex registers pin assignments.
Jay West wrote:
  The 2748A/B paper tape reader uses the "8-bit
duplex register interface".
 That would lead me to believe it's an 8 bit interface, not a 16 bit one.
 I have full docs (& schematics I believe) for both the 2748B and the 8-bit
 duplex register interface board. I have two of those units presently
 running, so I can get the cable pinout too if you'd like (but I believe the
 cable diagram is in the interface manual). Let me know if you still need
 them.
 One word of caution about the facit 4070 punch... as I found out when I got
 mine - the facit had a board in it that was replaced depending on what
 electrical spec the system you were attaching it to used. I seem to recall
 that you had to specify which (of many) interfaces you wanted on the punch
 when you ordered it. So just because you find a 4070 punch doesn't mean it
 has the right board in it to hook up to the 8-bit duplex register board (hp
 punches and readers both used the 8-bit duplex register board). Matter of
 fact, unless it was found with an HP system, it probably DOESN'T have the
 right board for the HP. You can't tell from the outside either, as I've seen
 the RS-232 interface board in the punch presents a DB25 externally - just
 the same as the HP version of the card does (which is decidedly NOT RS-232).
 Jay West
 ----- Original Message -----
 From: Tony Duell <ard(a)p850ug1.demon.co.uk>
 To: <classiccmp(a)classiccmp.org>
 Sent: Friday, June 29, 2001 12:41 PM
 Subject: Re: HP2748A papertape reader : connector ?
  >
 > At 09:22 PM 6/28/01 +0200, you wrote:
 >
 > >A recent dumpster dive yielded a HP2748A papertape reader. Does anyone 
have
  > >the interface spec's for this device
handy ?
 >
 >
 >       I think *some* of HP's paper tape punches and readers use the 
 82032
   parallel
interface. It's a 16 bit parallel interface with several 
 I suspect this is highly likely since the 16 bit parallel interfaces,
 like the 82032, 98032 (for the 9825, etc) were used for many 
  character-based
  (and other) peripherals.
  additional handshaking lines. Each data line can
be set as Input only, 
 I would be suprised if a paper tape reader used all the capabilities of
 that interface, though. Most likely there are 8 outputs from the tape
 reader (1 per data track), a data strobe signal (produced from the
 sprocket track, and either an input signal to cause the reader to advance
 one character (and read it) or one to start the tape moving, whereupon
 you get data strobes every so many ms. Maybe signals for error (tape run
 out, etc) and direction control
 There's not that much you need for a paper tape reader after all...
 > Output only or In and Out. I think have one around here somewhere that 
 came
  > off of a PT punch.  You should have grabbed
the PT punch, I think the 
 Facit
   is what
HP used or perhaps I should say one of the ones that they 
 The Facit 4070 is what _everyone_ used :-). Yes, HP used it for a time
 (one of the options for the 98032 is certainly to connect to a 4070, and
 it was used with larger machines as well). So did Philips (on the P800
 series). I've got a 3rd party card to link it to the DEC Unibus, and
 information on a similar card for Omnibus. Oh, and my Fluke DVM system
 has an option card to drive the 4070.
 I've even seen other paper tape punches (Trend made one based on the GNT
 Model 34 mechanism) that have the same interface. The 4070 was almost a
 de facto standard for paper tape punches.
 > used.   What kind of connector is on your PT reader?  I think most of 
  the
 >
 > If its's the unit I'm thinking of, it's a connector similar to the ones
 > used for V.35 interfaces.
 >
 > -tony
 >
 >