What did computers without screens do?

Charlie Carothers csquared3 at tx.rr.com
Mon Dec 14 11:17:10 CST 2015

On 12/12/2015 6:11 PM, Eric Christopherson wrote:
> On Sat, Dec 12, 2015, Mike wrote:
>> The one question I do have for the older gentlemen on here is what in the world did the computers without a screen to look at do? Now I know about the tape, cassette tape's and even the paper with the hole punches in them but what kind of applications were they use for? Mathematics or? ? ?
I think that's a very inviting question for those of us who view those 
years with a good bit of fond nostalgia!

The first ones I personally encountered all read and punched 80-column 
cards.  Some read and wrote to physically rather huge disk drives which 
could store all of 5MB, but most of them read and wrote 7-track 1/2" 
wide magnetic tape.  The "display" was a line printer. These were 
strictly business systems used to maintain the needed data for insurance 
companies, banks, General Services Administration, and a local daily 

Later, rather more interesting ones to me, read and punched 1" wide 
paper tape.  Their primary output was to 1/2" magnetic tape, and their 
operator consoles were an I/O Selectric typewriter.  Some of them also 
had line printers.  They were more interesting to me because they were 
interfaced to optical character readers, and their main role was to 
control certain parameters in the OCR system but mostly to receive the 
characters which were read and write them to the mag tape.  The mag 
tapes were further processed on much larger computer systems as desired 
by the customers.

All text, no graphics at all.  Well, I did once write a graph plotting 
program that could plot data to a line printer.  It could even plot 
multiple graphs overlaid, and kept the curves separated by using a 
different text character for each input data set. That was fun. :-)

Please note that I did change the subject on you so folks would know 
this is not part of the abominable thread.

Charlie C.

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