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Clearing half a screen fast

Posted: Tue Feb 09, 2021 12:10 pm
by mikefromca
The way I cleared about half a screen in the past with QuickBasic for DOS is with these commands:

Code: Select all

for n% = 1 to 15
locate n%,1
print space$(80)
next n%
Now when I look at the output with DOSBOX running at 6000 clock cycles, the execution is slowish where I really notice the flicker when the screen clears.

I might have to roll out a fast assembly routine, unless someone knows how to clear half a screen much faster.

The reason why I need to do this is because I am making a live data logger and I need to see the data at a certain section of the screen, and without clearing part of the screen, I'll see incorrect (old data) as the amount of fresh data varies every time.

Re: Clearing half a screen fast

Posted: Tue Feb 09, 2021 7:20 pm
by angros47

Code: Select all

VIEW PRINT 1 TO 15
CLS

Re: Clearing half a screen fast

Posted: Fri Feb 26, 2021 2:04 pm
by mikefromca
Oh wow. and here I rolled out my own ASM routine. This forum doesn't want to email me when I get new posts.