Compass - how to get started with BIOS routines

By Frederik Dumarey

Supporter (3)

Frederik Dumarey's picture

20-10-2021, 17:25

Hello all, had MSX since 30 years, bought a MSXVR recently and wanted to learn (at last) assembly oO .
So since Compass 1.2 went freeware (MSX fair Nijmegen) I wanted to started with this very good (if not the best) assembler IDE.

But: some problems:
- I start compass.com in DOS2 mode, so typical no MSX BIOS and MSX BASIC interpreter present in memory map.
- I wrote some assembler code to use MSX BIOS routines, and ORG #9000
- When launching GO #9000 nothing happens
- Think I have to put the BIOS ROM again in page 0 and 1, no? How do I do this in Compass, I tried System - Memory - went to page 0 and 1 and changed to primary slot 0-0. But still doesn't work Crazy

Already learned that if DOS programm I can start at #0100 but only DOS BIOS, if I start at #4000 (ROM) I can include MSX BIOS, and if starting above #8000 I can use BASIC interpreter calls.

Any help much appreciated!
Fred.

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By turbor

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turbor's picture

20-10-2021, 22:21

What you describe should work
You should indeed go to System->Memory and then in the bottom-right set Page 0 to 0-0 to select the BIOS before launching GO#9000. Compass will activate the memory as specified, load the registers and then call #9000 for you.
So I assume something else is going on.
What exactly do you mean with 'nothing happens'? Do you simply return to compass?Does the MSX hang? More info will help determine what is going on.

Could you share your code so that we can try to reproduce your situation?

By Frederik Dumarey

Supporter (3)

Frederik Dumarey's picture

21-10-2021, 23:26

Case closed, Thanks a lot turbor to analyse the code Smile
Did everything right, but the code contained MSX1 BIOS calls in the higher regions instead of the low region BIOS calls. Did follow some examples of MSX Club Magazine #6 Z80 course, but in that time only MSX1 existed Running Naked in a Field of Flowers

By AxelF

Champion (389)

AxelF's picture

24-10-2021, 14:17

Nice that Copass 1.2 is free now, is the free version newer than version 1.2.09 that i already own?. (does it have bugfixes.?
Where can i download the free version.?