Using the CRT unit in a console program -- GoToXY(24,80) scrolls up.

[Curt Carpenter]

I'm using linux/ubuntu and the CRT unit in a console program.  The terminal accessed with CRT iprovides 24 lines with 80 characters per line.  If I execute

Code: Pascal  [Select][+][-]

1. GoToXY(24,80); //Wrong -- should be 80,24 as marcov noted!
2. write('X');
3.  

the terminal displays an X on line 24, column 80, but it also causes the terminal to scroll up one line.  Is there a way to defeat the scrolling action?  It's been a long time since I played with the CRT unit -- I'm sure this is an ancient problem, but I can't remember the solution.  Hoping someone here remembers it 

[marcov]

Not really (and it is gotoxy(80,24) btw).  Typically if you want to do fullscreen drawing, the video unit is recommended.

[cdbc]

Hi Curt
I fiddled with 'crt' a while ago, you're welcome to have my findings...
I do seem to remember, having the terminal-window 1 line bigger than the "crt-viewport" to avoid the scrolling...
Attached you'll find some stuff to play with
eta: for the demo to run un-garbled, you'll have to make your terminal window 97x31 cols/lines... 
Regards Benny

[Curt Carpenter]

Not really (and it is gotoxy(80,24) btw).  Typically if you want to do fullscreen drawing, the video unit is recommended.

Yes, (80,24) -- sorry.  I'll look into the video unit.

[Curt Carpenter]

Hi Curt
I fiddled with 'crt' a while ago, you're welcome to have my findings...
I do seem to remember, having the terminal-window 1 line bigger than the "crt-viewport" to avoid the scrolling...
Attached you'll find some stuff to play with
eta: for the demo to run un-garbled, you'll have to make your terminal window 97x31 cols/lines... 
Regards Benny

I'll look at the code Benny, thanks.  Had forgotten how much fun it was to work with a text-only CRT screen!

[marcov]

Not really (and it is gotoxy(80,24) btw).  Typically if you want to do fullscreen drawing, the video unit is recommended.

Yes, (80,24) -- sorry.  I'll look into the video unit.

There is a tetris in the FPC demoes, and of course the turbo/free vision (including the textmode IDE) also uses it.

[Warfley]

You can also check out my LazTermUtils library, you can take a look at the color example, which prints the whole screen at like 60-100 fps (on linux, on windows only 30, because the windows terminal is very slow). So you can use it to make games if you want to 😅

https://github.com/Warfley/LazTermUtils/blob/master/example/Colortest.lpr