memory location of screen width in screen 1?

Rookie (31)

31-05-2020, 04:46

I'm hoping someone can help.
I'm trying out x-basic, which seems great, but the lack of a WIDTH function is causing some issues with my program.
the msx2 technical handbook suggests that it's at either memory location F3AFH or F3B0H, but peeking, poking, vpeeking or vpoking these locations seems to do nothing and I can't seem to find the memory location in any of the other books I've tried.

Does anyone know the proper memory location for the text width in screen 1, or possibly an x-basic workaround for setting the width to 32?

Thanks.

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Van epolesi

Supporter (2)

31-05-2020, 08:13

F3AFH is the width for the NEXT screen 1 mode change.
F3B0H is the width of the CURRENT text screen.
Changing none of them will change the current screen width, but.. try this:

POKE &HF3AF,32 : SCREEN 1

It should set screen 1 with width 32.

Van theNestruo

Champion (351)

31-05-2020, 10:00

Actually, POKEing $F3B0 (LINLEN) and $F3B1 (CRTCNT) does affect current screen width for BASIC instructions (CLS, PRINT, ...)
Given that BASIC's PRINT "handles" the scrolling of the name table if you print beyond the last line... this POKEs can be used to print a border/HUD, then POKE those vlaues, then handle the game area using PRINT to get "automatic" scroll

Dummy example: https://msxpen.com/codes/-M8diFXhzmmoKsHOYIYA

Reference: http://map.grauw.nl/resources/msxsystemvars.php

Van thegeps

Paragon (1031)

31-05-2020, 11:56

cool trick theNestruo

Van Pineapple

Rookie (31)

31-05-2020, 16:52

Thanks! looks like I had the memory location, but didn't know what to do with it.