Rom program to exit to basic and with call to run again?

Paladin (750)

23-04-2007, 14:30

Hello!
I am currently trying to learn some z80 machine code,i am a complete newbie at it,my first steps involve basic programs with some machine code in the form of data statements.

I am interested to create some small roms (no more than 8kbytes).

However i would like to know if there is a way to be able to run those small roms through a cartridge,create a routine somehow that would make the game have an exit option and then when pressed to return to basic,and after that if i want with a call to make the game run again.(execute a machine code,or basic loader that would allow me to run cartridge again)

Is this possible?

Sorry if i did not explain well.
Do you have any links for newbies that want to learn z80 coding on msx platform?
Thanks

By jltursan

Prophet (2619)

23-04-2007, 14:58

Um, the fastest way (and the easiest) to start programming little ROMs is using an emulator and cross assemblers. Both main emulators, OpenMSX and BlueMSX works fine although the BlueMSX debugger it's by now, easier to master. About assembler, most of them are enough for a newbie; asMSX has some facilities for creating ROMs automagically; but if you prefer, you can use the rest by creating the ROM by hand. Don't try to implement extra code to return to BASIC and such things, it's totally useless. Try to focus on the ROM itself.
There's no special Z80 tutorial for MSX, once you feel comfortable with the Z80 assembler (there're tons of very good Z80 tutorials on the net), you need to look for information about the specific MSX hardware: VDP, PSG, etc and of course familiarize as soon as possible with the BIOS calls.
Studying little MSX examples is always a good idea, you can find snippets on pages like MSX Assembly page or Karoshi Development Forum :)

By NYYRIKKI

Enlighted (6067)

23-04-2007, 18:22

Yes, it is possible and not even too hard...

Check out MSX2 Technical handbook chapter 7.3 for details.
http://www.konamiman.com/msx/th-5b.txt

By Manuel

Ascended (19467)

23-04-2007, 19:36

jltursan: note: feel free to check on #openMSX on irc.freenode.net to get a Win32 binary of the openMSX debugger GUI.

By nikodr

Paladin (750)

23-04-2007, 19:56

Thank you!I will certainly have to check out plenty of things,but i think it is time to move away from basic and to go to assembly for speed.

By jltursan

Prophet (2619)

23-04-2007, 20:56

Thanks for your offer Manuel!; but I've no problem to wait for the final release (although I'm eager to see the new GUI ) and I'm a bit lazy about IRC,..... I've never used one!

By Manuel

Ascended (19467)

23-04-2007, 21:26

The release isn't making much progress at the moment and it would be good to have more beta testers... So please stop by! You can also use a web based iRC client like ircatwork.com.

By Manuel

Ascended (19467)

23-04-2007, 21:47

OK, I put online a Win32 binary of the latest code, please give this stuff a spin and tell us what you think. It's not released yet, so it probably contains some bugs. AFAIK there's at least a bug with the scrollbar of the debugger view. And there's no documentation yet.... But still, have fun.