13 Dec
2020
13 Dec
'20
6:37 p.m.
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
13 Dec
13 Dec
6:48 p.m.
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
7:15 p.m.
DIDN't the datapoint 3300 have that?
On Sun, Dec 13, 2020 at 9:49 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.
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
7:34 p.m.
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
10:10 p.m.
On Dec 13, 2020, at 18:37, Stan Sieler 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).
Printing terminals. Just pull the printed paper up from where it has fallen
behind your Teletype or DECwriter or Silent 700 or Terminet.
(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).
That was, kind of sort of, the on-screen effect, but it could vary.
Between 1977 and 1981 I used 2640B terminals which had been purchased
without many options. They didn?t have lower case characters (these
were displayed as upper case characters, and sometimes hilarity ensued),
and they had about 1KB of display memory.
Now you may be thinking that 24 rows of 80 characters is more like 1920
characters which would require a little more than 1KB of display memory,
and you would be correct.
The tricky bit about the 264X display controller is that it is reading
display memory as a linked list of fixed-size short chunks (under 20
bytes) and the last one has an end-of-line indicator in it (it is an
ASCII terminal and byte values 0x80-0xff are interpreted as display
controls). So a short line of text doesn?t take up as much display
memory. Which means you can have more of them in display memory.
So your 2640B with 1KB display memory has scrollback if most lines that
you have in memory are short, but can only fill its screen halfway if
all lines are long.
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.)
I think the VT100 did not. I?m not sure it matters. The 2640A would
predate the VT100.
I wonder if the termcap da and/or db flags would turn up some older
terminals with the same feature. (These indicate display above and
display below.)
-Frank McConnell
2:50 a.m.
On 12/13/2020 10:10 PM, Frank McConnell via cctalk wrote:
On Dec 13, 2020, at 18:37, Stan Sieler wrote:
I know you're
trying to be cute because I believe the "page" wasn't
paper the OP was referring to.
However the Microdata Scribe, which was done by an engineer who later
worked on a dot matrix printer for Data Products and manufactured in
Irvine had reverse paper motion.
You could align the paper, set the page size which would logically fix
the printer, and then control the motion over the page as needed.
It could print anywhere on the 14" platten w/o extra motion, so it was
able to quickly move around the page doing either graphic printing, line
printing which emulated a plotter, or print characters as needed.
Not related to scroll back or paper motion it had a really powerful font
support mechanism.? All of this was done when memory became cheap and
reliable enough that you could have more than just display memory and a
smidge of ram for a display processor in the terminal.
I didn't see the functions of the Scribe duplicated in any other printer
in the price or performance class.
The other thing that is nice about the printer is that it used the same
OEM head that the TI 8xx series printers did, so you could buy them very
economically in the day, the ribbons were the same and cheap.? Today
they still are among the most common NOS around for such parts.
I bought the optional keyboard, so I had a KSR printing terminal and
could scroll back with the printer.? It was essentially equivalent to
the DEC LA printers, but the scroll back could be done from the keyboard.
thanks
Jim
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).
Printing terminals. Just pull
the printed paper up from where it has fallen
behind your Teletype or DECwriter or Silent 700 or Terminet. (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).
That was, kind
of sort of, the on-screen effect, but it could vary.
Between 1977 and 1981 I used 2640B terminals which had been purchased
without many options. They didn?t have lower case characters (these
were displayed as upper case characters, and sometimes hilarity ensued),
and they had about 1KB of display memory.
Now you may be thinking that 24 rows of 80 characters is more like 1920
characters which would require a little more than 1KB of display memory,
and you would be correct.
The tricky bit about the 264X display controller is that it is reading
display memory as a linked list of fixed-size short chunks (under 20
bytes) and the last one has an end-of-line indicator in it (it is an
ASCII terminal and byte values 0x80-0xff are interpreted as display
controls). So a short line of text doesn?t take up as much display
memory. Which means you can have more of them in display memory.
So your 2640B with 1KB display memory has scrollback if most lines that
you have in memory are short, but can only fill its screen halfway if
all lines are long.
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.)
I think the VT100
did not. I?m not sure it matters. The 2640A would
predate the VT100.
I wonder if the termcap da and/or db flags would turn up some older
terminals with the same feature. (These indicate display above and
display below.)
-Frank McConnell
7:52 a.m.
On 12/14/2020 04:50 AM, jim stephens via cctalk wrote:
However the Microdata Scribe, which was done by an
engineer who later worked on a dot matrix printer for Data
Products and manufactured in Irvine had reverse paper motion.
You could align the paper, set the page size which would
logically fix the printer, and then control the motion
over the page as needed.
It could print anywhere on the 14" platten w/o extra
motion, so it was able to quickly move around the page
doing either graphic printing, line printing which
emulated a plotter, or print characters as needed.
I had a 1970's Honeywell drum printer that was part of a key
to tape / tape to print system.
I think the printer was actually a mainframe product that
was adapted to this purpose.
It had a core memory that held several hundred characters.
The paper feed motor was
run from an analog servo amp, and could be commanded to
index forwards and backwards.
In hardware (no CPU) it had a rudimentary "text editor" so
you could place text from the core buffer anywhere on the
page. Since it had a pretty limited character set on the
drum, I came up with a bunch of overstrike combinations to
approximate the full ASCII special characters. So, for
instance,
< overstruck with ( was the { character. Pascal listings
looked pretty odd, but I could read them.
Jon
2:22 a.m.
On 2020-Dec-13, at 6:37 PM, Stan Sieler via cctalk wrote:
...
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.)
If it fits your definitions, you might look into the Teletype Model 40 if more info to
that below can be found.
On pdf.pg.60 of this article:
http://www.bitsavers.org/pdf/datapro/alphanumeric_terminals/Datapro_C25-010…
the Model 40 is shown with "Paging: Opt. 2/3 pages" and "First production
delivery: 10/73"
6:25 a.m.
On Dec 13, 2020, at 9:37 PM, Stan Sieler via cctalk
<cctalk at classiccmp.org> 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.)
Definitely not any of the DEC plain terminals. However, the VT71/t (a.k.a., VT72), an
LSI-11 based smart terminal that did local editing of a whole file, had a lot of memory
only a small part of which was displayed. And before that was the VT20, a very similar
device controlled by an 11/05 (one for two "heads"). The VT71 dates to around
1977.
Depending on how loose your definition of off-screen memory is, the console display of the
CDC 6000 mainframes (from around 1965) might qualify.
paul
1237
days inactive
1237
days old
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