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Re: Purely historic question: VT200 text graphic programming

 
 
Martin Gregorie
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      03-11-2011
On Fri, 11 Mar 2011 11:52:13 +0000, Jorgen Grahn wrote:

> On Thu, 2011-03-10, Martin Gregorie wrote:
>> On Thu, 10 Mar 2011 20:31:11 +0000, Grant Edwards wrote:
>>
>>> You tricked me by saying only DEC VAX/VMS programmers would know what
>>> it was. In fact, many, many Unix programmers knew about curses (and
>>> still do) and very few VMS programmers ever did. C wasn't very widely
>>> used under VMS, and VMS had it's own screen formatting and form
>>> handling libraries.
>>>

>> From the context the "only DEC VAX/VMS programmers" remark applied to
>> the VT-100. However, the OP is wrong about that - VT-100s were
>> well-known and popular devices in the 8-bit microprocessor world too,
>> together with assorted clones. In addition, many other terminals had a
>> VT-100 emulation mode. IIRC all the Wyse terminals had that.

>
> But he wrote VT-200, not VT-100. I assumed he meant those (vt200) had
> some exotic graphics mode. The VT-xxx series was pretty heterogenous,
> although most of us think of them as more or less fancy VT-100s.
>

You're right - he did say VT-200. Can't remember using one. However, I
did buy a used VT-103 at some point and dumped it fairly rapidly as it
had no manuals and I couldn't get it to work as a terminal (no wonder -
I've since found out that it was really a standalone box with an LSI-11/23
crammed into the VT-100 box). It got swapped for a Wyse 120 - an
excellent terminal with a white phosphor rather than green.

Grayshark was right too: the ANSI control code standard preceded the
VT-100 - I live and learn - and because of that there was no commonality
between VT-50/52 and VT-100 escape codes. Details here:
http://vt100.net/vt_history

BTW, there was no such thing as a VT-200 - there was a VT-220 text
terminal (which I think the OP was remembering) and the VT-240 and 241
terminals, which were totally different graphics terminals that accepted
Tektronics graphics commands: comparing a VT-220 to a VT-240/241 would
be like comparing an Epson dot-matric printer to an HP 7485 plotter!


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Grant Edwards
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      03-11-2011
On 2011-03-11, Martin Gregorie <(E-Mail Removed)> wrote:

> BTW, there was no such thing as a VT-200 - there was a VT-220 text
> terminal (which I think the OP was remembering) and the VT-240 and
> 241 terminals, which were totally different graphics terminals that
> accepted Tektronics graphics commands: comparing a VT-220 to a
> VT-240/241 would be like comparing an Epson dot-matric printer to an
> HP 7485 plotter!


The 220 and 240/241 weren't fundamentally different display
technologies they way a dot-matrix differs from a pen-plotter. Both
were raster-scan CRT tubes (AFAICT, they used identical CRT tubes and
driver hardwar). When used in text mode, the 240 wasn't really any
different than the 220. But, the 240 also supported a graphics mode
that allowed apps to draw using vector commands). I remember writing
an app using the ReGIS command set to draw a clock with a moving
second hand on a 240.

Comparing a vt220 to a vt240 is like comparing a black-and-white epson
9-pin dot-matrix printer that can't do graphics with a balck-and-white
epson 9-pin dot-matrix printer than can do graphics.

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Martin Gregorie
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      03-12-2011
On Fri, 11 Mar 2011 19:32:53 +0000, Grant Edwards wrote:

> On 2011-03-11, Martin Gregorie <(E-Mail Removed)> wrote:
>
>> BTW, there was no such thing as a VT-200 - there was a VT-220 text
>> terminal (which I think the OP was remembering) and the VT-240 and 241
>> terminals, which were totally different graphics terminals that
>> accepted Tektronics graphics commands: comparing a VT-220 to a
>> VT-240/241 would be like comparing an Epson dot-matric printer to an HP
>> 7485 plotter!

>
> The 220 and 240/241 weren't fundamentally different display technologies
> they way a dot-matrix differs from a pen-plotter. Both were raster-scan
> CRT tubes (AFAICT, they used identical CRT tubes and driver hardwar).
> When used in text mode, the 240 wasn't really any different than the
> 220. But, the 240 also supported a graphics mode that allowed apps to
> draw using vector commands). I remember writing an app using the ReGIS
> command set to draw a clock with a moving second hand on a 240.
>
> Comparing a vt220 to a vt240 is like comparing a black-and-white epson
> 9-pin dot-matrix printer that can't do graphics with a balck-and-white
> epson 9-pin dot-matrix printer than can do graphics.


Sorry if I wasn't clear: I was intending to compare APIs rather than the
display mechanisms - I am aware that both text terminals and vector
graphics terminals are raster devices, not vector like oscilloscopes.
What I was getting at is that the API used to cause graphics or text to
be output on a dot-matrix printer is totally unlike that used to draw to
same representations on a pen plotter.


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rzed
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      03-12-2011
Anssi Saari <(E-Mail Removed)> wrote in
news:(E-Mail Removed):

> Grant Edwards <(E-Mail Removed)> writes:
>
>> C wasn't very widely used under VMS, and VMS had it's own screen
>> formatting and form handling libraries.

>
> Just curious, what language was widely used in VMS? My VMS
> experience is limited to running Maple for a math course in the
> university in early 1990s. Didn't know how to do much more than
> start Maple, probably just dir, logout (or was it logoff?) and
> ftp


Did you say "was"? The last time I did any programming on a VMS system
was ... about 5 1/2 hours ago. Our shop runs OpenVMS now, programs
mostly in C and BASIC. I've quietly insinuated Python into the mix
over the last few months, and that has helped my sanity considerably.

I did use the curses library with Vax C years ago, though online data
entry programs used the SMG library.

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Dennis Lee Bieber
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      03-12-2011
On Fri, 11 Mar 2011 18:02:47 +0000 (UTC), Martin Gregorie
<(E-Mail Removed)> declaimed the following in
gmane.comp.python.general:

> On Fri, 11 Mar 2011 11:52:13 +0000, Jorgen Grahn wrote:
>
>
> Grayshark was right too: the ANSI control code standard preceded the
> VT-100 - I live and learn - and because of that there was no commonality
> between VT-50/52 and VT-100 escape codes. Details here:
> http://vt100.net/vt_history
>

Guess I was fooled by 1) I think VT-100's had a option toggle that
would enable VT-52 emulation, and 2) based on a comment on Wikipedia

"""
The first standard for ANSI escape sequences was ECMA-48, adopted in
1976. It was a continuation of a series of character coding standards,
the first one being ECMA-6 from 1961, a 6-bit standard from which ASCII
originates. ECMA-48 has been updated several times and the current
edition is the 5th from 1991. It is also adopted by ISO and IEC as
standard ISO/IEC 6429. The name ANSI escape sequence dates from the
years 1981 to 1997, but in 1981 ANSI adopted ECMA-48 as the standard
ANSI X3.64 (and later, in 1997, withdrew it).[1]
"""

Note the last sentence starting "The name ANSI..."
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Blockheads Oi Oi
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      03-12-2011
On Mar 11, 9:17*am, Anssi Saari <(E-Mail Removed)> wrote:
> Grant Edwards <(E-Mail Removed)> writes:
> > C wasn't very widely used under VMS, and VMS had it's own screen
> > formatting and form handling libraries.

>
> Just curious, what language was widely used in VMS? My VMS experience
> is limited to running Maple for a math course in the university in
> early 1990s. Didn't know how to do much more than start Maple,
> probably just dir, logout (or was it logoff?) and ftp


The opposite of widely used, how about C with embedded SQL or CORAL
66
 
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Grant Edwards
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      03-12-2011
On 2011-03-12, Martin Gregorie <(E-Mail Removed)> wrote:

> Sorry if I wasn't clear: I was intending to compare APIs rather than the
> display mechanisms - I am aware that both text terminals and vector
> graphics terminals are raster devices, not vector like oscilloscopes.
> What I was getting at is that the API used to cause graphics or text to
> be output on a dot-matrix printer is totally unlike that used to draw to
> same representations on a pen plotter.


You're right. The point I was trying to make was that the 240 was a
superset of the 220, and could be used identically as the 220 was
used. Back in the years when I used a 240 for 8 hours day the the
exact same API was used for the 240 as was used for a 220. The only
exception was the afternoon I decided to write a clock app just to see
how the graphics mode on a 240 worked. I have no idea why my employer
bought 240's instead of 220's. It's not like anybody spent a lot of
time looking at drawings of wombats -- in fact, I was probably the
only person at the company who knew you could. [Talk about obscure VMS
allusions...]

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Martin Gregorie
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      03-12-2011
On Sat, 12 Mar 2011 17:11:37 +0000, Grant Edwards wrote:

> The point I was trying to make was that the 240 was a
> superset of the 220, and could be used identically as the 220 was used.
>

Fair enough: I bow to hands-on experience.

My source - http://vt100.net/vt_history - Says "There is no VT200 as
such; the VT220 is a text terminal, while the VT240 and VT241 are
graphics terminals, supporting Digital’s ReGIS graphics and Tektronix
vector graphics." which I read to mean that a 240/241 wouldn't accept the
same command set as the 220.


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Martin Gregorie
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      03-12-2011
On Fri, 11 Mar 2011 23:00:25 -0800, Dennis Lee Bieber wrote:

> Note the last sentence starting "The name ANSI..."
>

Indeed. I'm pretty certain that the first time I met the term "ANSI" was
in connection with the DOS add-on 'ANSI driver' that allowed programs to
control the display by emitting escape codes - without it the DOS screen
was treated as a glass teletype.


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Grant Edwards
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      03-12-2011
On 2011-03-12, Martin Gregorie <(E-Mail Removed)> wrote:
> On Sat, 12 Mar 2011 17:11:37 +0000, Grant Edwards wrote:
>
>> The point I was trying to make was that the 240 was a
>> superset of the 220, and could be used identically as the 220 was used.
>>

> Fair enough: I bow to hands-on experience.
>
> My source - http://vt100.net/vt_history - Says "There is no VT200 as
> such; the VT220 is a text terminal, while the VT240 and VT241 are
> graphics terminals, supporting Digital???s ReGIS graphics and Tektronix
> vector graphics." which I read to mean that a 240/241 wouldn't accept the
> same command set as the 220.


Yes, that is what it sounds like from that description, but the 240
(mono) and 241 (color) could be used as normal ASCII/ANSI text
terminals (and most of the time they were). After thinking about it
more, I do remember one graphical app that I used regularly, and that
was a .dvi file previewer that let you view a document typeset by
TeX/LaTeX. Due to the size/resolution of the screen, it wasn't usable
to actually read a document, but you could check to see if some
particular formatting detail turned out the way you wanted it to.

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