character codes, was RE: Really stupid PDP assembler question

From: David V. Corbin <dvcorbin_at_optonline.net>
Date: Sun Jun 27 10:28:01 2004

Tony,

I was actually refereing to even earlier printing calculators that had a
single vertical bar per position with the numbers 0-9 on each one. The bar
would be raised/lowered an an individual striker per position would fire.
There as no left-right movement along a "carriage". The first machine I saw
this etup on was in the mid-60's at one of the companies my dad worked for.
Don't recall the computer model, but it was always refered to as "the old
system", actual (program) input and display on the front panel was binary
toggle swithes. I had pictures, and stuff that were destroyed in the "great
storage unit flood" a few years back. A quick Google did not turn up any
hits, but I have sent off a few e-mails to some people who yorked with my
dad back in the day, to see if they remember anything.....

David.


>>> -----Original Message-----
>>> From: cctech-bounces_at_classiccmp.org
>>> [mailto:cctech-bounces_at_classiccmp.org] On Behalf Of Tony Duell
>>> Sent: Saturday, June 26, 2004 5:42 PM
>>> To: cctalk_at_classiccmp.org
>>> Subject: Re: character codes, was RE: Really stupid PDP
>>> assembler question
>>>
>>> >
>>> > On Fri, 2004-06-25 at 16:47, David V. Corbin wrote:
>>> >
>>> > > "What significant advantage did octal have over hex notation
>>> > > (especially in the late '60s timeframe)?"
>>> >
>>> > I'm a bit skeptical of the printer-hardware answer. Printing
>>> > calculators don't care about notation, only humans do.
>>>
>>> Remember this predates dot matrix printers on calculators.
>>> The printers we're talking about had a typewheel with
>>> perhaps 12 positions round it (0-9, decimal point, minus
>>> sign). Either one per column or one that was shifted across
>>> the paper.
>>>
>>> It would have been possible to make one with 16 characters
>>> round the wheel, but I've never seen one.
>>>
>>> > (Why five? how many fingers you got?)
>>>
>>> 8 (and 2 thumbs), like most people :-)
>>>
>>> -tony
>>>
Received on Sun Jun 27 2004 - 10:28:01 BST