when was memory "above" the terminal screen invented?

[Warner Losh]

On Sun, Dec 13, 2020, 7:49 PM Nigel Johnson via cctalk <
cctalk at classiccmp.org> wrote:

> 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.
>

I'm sure it did not have scroll back. I used a lot of these terminals back
in the day.

Warner

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
>