On Thu, 25 Jul 1996, John Korb wrote:
 
> Frank wrote:
>
> >Please give me escape sequences setting HP 700/92 terminals in 132 columns
> >and back in 80 columns mode. Who knows the sequence and intrinsic call in
> >Pascal detecting whether the setting was successful, and returns whether
> >current setting is 80 or 132 columns.
>
> I've got a few programs that play around with the REFLECTION display, and
> while I'm on vacation this week and don't have access to the listings, I can
> describe the method I used to determine the screen dimentions.  I would
> imagine that the method should work for almost any HP terminal back to the
> HP2640B.
>
>
> Turn echo off (FCONTROL 13?).
> Suppress automatic carriage return/line feed (FSETMODE something).
> Set read timeout on $STDIN (FCONTROL 4?) to something like 10 seconds.
> FWRITE to $STDLIST "Sense Absolute Cursor Position" (Esc,a) using CCTL 208.
> FREAD from $STDIN the cursor position string.
> Save the cursor position string as "Screen End Address".
> FWRITE to $STDLIST "Home Cursor","Cursor Left","Sense Absolute Cursor Position"
>    (Esc,H,Esc,D,Esc,a) using CCTL 208.
> FREAD from $STDIN the cursor position string.
> Enable automatic carriage return/line feed (FSETMODE something).
> Turn echo on (FCONTROL 12?).
> Extract the row and column coordinates from the cursor position string (I
>    think REFLECTION and HP terminals send ESC "&a079c023R" when in 24x80 display
>    mode.  The number before "c" is the column number, the number before "R" is
>    the row number.  The row and column numbers are zero-based.)
> If the screen dimensions are what you need then
>    FWRITE to $STDLIST the "Screen End Address" string using CCTL 208.
>    Set a flag to indicate that the screen mode DOES NOT need to be changed upon
>       exit.
> Else
>    Save the information obtained so the screen can be returned to its previous
>       dimensions when you are done.
>    Change the screen dimensions to what you desire.
> EndIf
>
>
> The trick to the above is very simple.  By moving the cursor to the top left
> corner of the screen, the cursor is moved to screen coordinate 0,0.  Moving
> the cursor left one position causes the cursor to wrap around to the very
> last position of the screen, row 23, column 70 in a 24x80 display, row 23,
> column 131 in a 24x132 display, row 47, column 131 in a 48x132 display, etc.
> I've used the method mostly with REFLECTION when I needed to go from a 24x80
> to a 48x132 or 60x132 display for some very complex output format.
> Personally, unless you are running REFLECTION on a PC with a 17" monitor,
> I'd stay away from displays with more elements that 24x132 - unless you like
> eyestrain.  I also remember a quirk caused by the carriage return/line feed
> that occurs after the FREADs.  I know FSETMODE came into play, but I don't
> remember the option.  You can probably find the option in the intrinsics
> manual.
>
> I know that in later revisions of the program I took the absolute cursor
> addressing and converted it over to screen relative addressing, but the
> above is simpler and gets the job done.
>
> Hope the above helps.  I'll be back in the office the middle of next week.
> If you contact me then, I can dig into the source and find all the little
> quirks.
>
> John
> --------------------------------------------------------------
> John Korb                            email: [log in to unmask]
> Innovative Software Solutions, Inc.
>
> The thoughts, comments, and opinions expressed herein are mine
> and do not reflect those of my employer(s), or anyone else.
>
Dear John:
 
Thank you for the detailed explanation. I would be glad if you can send
me some sample program details.
 
Some questions:
 
Is CCTL an intrinsic?
 
Next week I'll be here. In the period Aug 7-22 I'll be on vacations.
May be, we can continue the discussion after that.
 
                                           Thankx
                                              Frank
 
  |\  /~ ~~|~~~ Family : NAGY; first name : FERENC; title : Ph. D.
  | \ |   -+-   Institute of Isotopes of the Hungarian Academy of Sciences
  |  \|    |    1121 BUDAPEST Konkoly-Thege M. ut 29, HUNGARY (1525 Bp. POB 77)
`-'   '  `-'    E-mail : [log in to unmask]
 
Fax: (36)-1-156-5045, work phone: (36)-1-275-4351, home phone: (36)-1-277-4229.
Home address: H-1214 BUDAPEST Raketa u. 29. I. 3.
 
There are 3 kinds of programming errors:  syntactical, semantical and mystical.
The programmers have to suck up the users just as much as absolutely necessary.