Sinclair ZX80 / ZX81 / Z88 Forums

Hello ZX Fanz,

Is there a POKE or some simples BASIC way of reducing the number of lines that can be viewed on a ZX81 screen?

I remember some SInclair User 1K "Race car" program that did just this, but much of my collection was either lost to time or destroyed in a garage fire.

Thanks in advance for your help,

Shaun.

With this software from Wilf Rigter, can set the screen to any size, and giving more time to run code. When less time is used for display, then more can be used for code.

http://www.user.dccnet.com/wrigter/inde ... va2005.htm

Thanks for the link, but there was also a way to do this in BASIC on an unexpanded ZX81 - unless my memory really is failing me.

Regards,

Shaun.

Maybe you're thinking of...

POKE 16418,X where X is the number of lines in the bottom part of the screen. This is normally 2, 0 gives 24 lines to the top part of the screen, 10 would devote 10 lines to the bottom and 14 to the top.

Not sure if this works on a 1K ZX81 though.

Regards;

Greg

Excellent, thanks!

HI ,
I have already experienced any D_file problems using this Poke…
I don't know what's the problem… but, a CLS, seem to corrupt the new screen setting.
Perhaps we had to reset the Poke to the initial value… before clear the screen.

I found a work-around to what I wanted to do which meant not POKEing anything

See my new Fruit Machine thread in this sub-forum.

Regards,

Shaun.

A CLS wil set the screen to 25 newlines.

To use smaller screens you must not use CLS.
The smallest screen is a POKE start of screen (DFILE-pointer) with #E9.

You can do this also for rest of screen unused lines