What did computers without screens do?

[Mike]

On Dec 14, 2015, at 12:11 PM, jnc at mercury.lcs.mit.edu (Noel Chiappa) wrote:

>> From: Mike
> 
>> 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?
> 
> There are a number of different generations, and the way they were used
> generally depended on what the computer in question had for I/O capabilities.
> 
> In the very earliest machines, the computations tended to be mathematical
> modeling; things that needed a lot of computing, but had very modest I/O
> requirements. The classic example was the hydrogen bomb calculations
> performed on ENIAC (which was originally built to do ballistics
> computations), but other similar ones included structural modeling, etc.
> 
> That class of application continued (and does so, to this day), but over
> time, more and more things got done using computers, as their capabilities
> (online storage, I/O, etc) grew. In general, the new applications were added
> to the existing ones, but did not supplant the earlier ones.
> 
> Starting with a computer in England called LEO:
> 
>  https://en.wikipedia.org/wiki/LEO_(computer)
> 
> they were also applied to business applications (inventory, payroll, billing,
> etc), which typically did more modest computations, but more I/O, which
> required better I/O capability (cards, tapes, printers, etc).
> 
> With the advent of timesharing in the early 1960's, it became common to add
> individual character-output terminals (initially printing, moving mostly to
> video terminals circa the mid-70's), and with the ability of users to
> interact with applications running on a computer, applications broadened even
> further; online text preparation was one common one.
> 
> The final phase came with the introduction of bit-mapped video terminals,
> which allowed the interactive users to use graphics, and images; the very
> earliest such systems were on time-sharing mainframes, but with the growth of
> personal computers, that technology migrated there (note that the very
> earlist PC's had only character-output terminals, mimicing their main-frame
> big brothers of the time).
> 
>    Noel

Thanks Noel for the great link and wow they still used LEO all the way up to 1981 crazy. This is what I am talking about just the knowledge I ca soak up here. . . Man I could read up on this stuff for years! Again thanks for the great info.