when was memory "above" the terminal screen invented?

[Nigel Johnson]

I'm pretty sure the DEC VT100 didn't have it.  It was very memory
-limited - the standard was 80x 24 and if you wanted 132 x 24 you had to
buy the advanced video option.

There was a demo program that made it look like it recovered data that
had been scrolled off the top of the screen, but I think it was just
re-sent form the computer.

cheers,

Nigel



Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU
Amateur Radio, the origin of the open-source concept!
Skype:  TILBURY2591 nw.johnson at ieee.org



On 2020-12-13 9:37 p.m., Stan Sieler via cctalk wrote:
> Hi,
>
> First, apologies if I asked this years ago (I've searched my archives, no
> hits :)
>
> When was the concept of memory "above" the screen invented for terminals?
>
> I.e., previously displayed data that had scrolled up and off the screen ...
> but could be retrieved (usually by scrolling down).
>
> (Sometimes called "scrollback", or "offscreen memory".)
>
> (BTW, I'm talking about terminal-local memory, not a scrollback implemented
> by the computer to which the terminal is connected.)
>
> The HP 2640A, 1974, had (IIRC) several pages of memory available ... the
> user could scroll
> backwards and see what had been on the screen before it scrolled off (as
> long
> as it hadn't been lost by having too much subsequent output).
>
> I suspect the DEV VT100, 1978, had it, but I can't find definitive proof
> online (sure, I can find VT102 emulators that have scrollback, but reading
> an old VT102 manual doesn't make it clear that it has it.)
>
> thanks,
>
> Stan