Sinclair ZX80 / ZX81 / Z88 Forums

I've noticed that it's fairly easy to generate 33 or 34 column text on the ZX81, so let's say I want 34 x 24 text display, is it possible to move the screen position left one character to compensate?

Also, if I wanted, say, 30 X 25 text (if that's possible), could I move the screen right and up easily enough?

Are there any assembly tricks to do such wizardry?

Thanks,

Shaun.

Count the columns in my game AIRPIPES and you have the answer.
You can move the text by a column when you alter the value in A just before calling the print from the ROM.

Since the ZX81 can handle less than 32 bytes (compressed screen) it can also handle more by just making a screen wirh more columns.
As for more textlines than 24: just increase the B-register.

However: the ROM will reset the screen to 32x24 when you use CLS, so this must be avoided ( make your own CLS).
The best way to use this all is in MC, so do not return to BASIC anymore.

See also Bodo's MAXDEMO

https://www.youtube.com/watch?v=HZd9fxS8mNg

http://bodo4all.fortunecity.ws/zx/maxdemo.html

and Wilf's NOVA

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

Siggi