HP2748A papertape reader : connector ?

From: Jay West <west_at_tseinc.com>
Date: Tue Jul 3 02:27:17 2001

Bob wrote...
> "Incorrect" may have been a poor choice of words....however I have
documentation
>
> that shows a HP2100 shipped by HP with the older reader interface board.
In
> fact
> one of the reader boards I have was removed from a basket-case 2100
system.
>
> I wounder when HP switched over, and why?

No Kidding!? That's truely interesting. You have my curiosity up, I'd love
to know what the deal is for my own future reference.

I do have a lot of sales literature and marketing collateral for these
systems, and all of them show the 2748B paper tape reader as using an 8-bit
duplex register board. Hummmmmmm.... You know what - is it possible that the
ones that use this "tape reader interface board" that you've seen are the
2748A reader and the B version uses the 8-bit duplex register board? All the
literature and docs I have shows the 2748B, I have nothing that relates to
the 2748A which is why I'm conjecturing this. One wouldn't think that HP
would release a board with the same electrical specs as the 8-bit duplex
board, so wouldn't you think the electronics in the reader would have to be
different for the two boards? Most interesting... could you check and see if
your reader is the A one that uses this board Bob? Or maybe show us a pinout
of the old style reader interface vs. the new style?

> Umm, how is the 2114 not an HP machine? (The 2114 was developed by HP.)
>
> Your thinking of the 2116 perhaps, which was originally developed by a
small
> firm that
> HP later absorbed?

I knew the first 21xx machine was already designed and put together by
another company, and HP just absorbed the company. When they saw how
sucessfull it was, they then came out with the other two. I was thinking
this first one was the 2114, and the HP made ones were the 2115 and 2116. I
stand humbly corrected - must be the 2116 that was absorbed and they made
the other two. The 2100 did come later. Interesting tidbit - one of HP's
largest users of the 2100 system was a company called "MeasureX". This
company had it's own engineering staff and redesigned the 2100 to be a
single cpu card. They sold this design back to HP and it became the 21MX
line. The MX in 21MX stands for MeasureX. I got this directly from a phone
call with the former VP of engineering of MeasureX, so I suspect it is
accurate historically.

> at least 1 2100A shipped using the older style interface board

I'm just wild guessing here, but is it possible that the 2100A that you got
had the tape reader (old style) added later and wasn't actually sold that
way from HP? The reason I'm wondering this is I have the sales/ordering
guide for the 2100A and the 2100S, and both only specify the 8-bit duplex
register. Most Strange! My earlier comments were based on the HP
sales/ordering guide, and in retrospect you're quite right, those guides
were almost certainly revised from time to time and earlier ones than mine
might indeed use the old style reader board. Again, I'm wondering if it's
not the A reader that used it?

> What is your definition of a '2100 machine'?
>
> 2114, 2115, and 2116 machines run HP 2100 software, and were the original
> processors
> used in HP2000 time share basic systems. They originated the HP board
interface
> used
> all the way up to the MX and E series. The software on the HP2100 archive
site
> is that
> which originally shipped with 2114 thru 2116 systems.
>
> If these classic machines are not 2100's, then what are they?

>From the sales/ordering guides that I have (but perhaps I'm reading them
wrong or drawing incorrect conclusions): The 2100 machine is a 2100 machine.
2100 was not a family or class of machines, it was a specific machine (2100
with option pack A or S). There is no difference in the A and S versions
except the S version included options as standard which were also available
from the outset on the A. From what I can gather, the 2114/5/6 machines were
not referred to as "2100's", they were referred to as 2114/5/6. Part of my
basis for this is logical - they wouldn't name the 2100 (which came later) a
2100 if that was the generic family name for the 2114/5/6 machines I'm
guessing. The early nomenclature of HP's mini products is *SO* confusing...
cpu's that were called 21MX's were later redesignated 1000 machines, etc.
Plus the whole 2000 thing that doesn't refer to a computer, but rather a
specific configuration of both hardware and software (for TSB). What a mess.
What's your take on this Bob?

Regards,

Jay West
Received on Tue Jul 03 2001 - 02:27:17 BST