Commodore 128 Alive!

Commodore 128 => 128 programmers => Topic started by: MIRKOSOFT on December 03, 2009, 07:44 AM

Title: GRAPHIC command executing in assembler
Post by: MIRKOSOFT on December 03, 2009, 07:44 AM
Hi!

I want to ask simple Q:

I need to allocate memory $1300 - $3FFF.

Simple method in BASIC v7 is using command GRAPHIC 1 and BASIC program will have starting address $4000 instead of $1C00.

How to execute GRAPHIC command with parameter in assembler?

I don't want to write any routine - better is using system routine.

Thanks for every reply.

Miro
Title: Re: GRAPHIC command executing in assembler
Post by: Hydrophilic on December 03, 2009, 03:33 PM
In BANK 14 or BANK 15 simply JSR $9F4F to allocate the BASIC VIC bitmap.

In BANK 14 or BANK 15 simply JSR $A022 to de-allocate the BASIC VIC bitmap.

In either case, any BASIC program in memory will be moved and re-linked, which can take several seconds for a large program.

You can check if the BASIC VIC bitmap is allocated by checking address $76.  If zero, bitmap is not allocated; otherwise it is allocated.

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