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.
Moving the margins on the screen
Re: Moving the margins on the screen
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.
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.
Re: Moving the margins on the screen
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
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
My ZX81 web-server: online since 2007, running since dec. 2020 using ZeddyNet hardware
http://zx81.ddns.net/ZxTeaM
http://zx81.ddns.net/ZxTeaM