MSX 1 Basic ROM disassembly

Por HansO

Paladin (672)

Imagen del HansO

29-05-2016, 12:05

Message and files sent to me by Stefano Bodrato.

Text by Stefano:

I'm at a good stage in disassembling the MSX 1 ROM.I based my work on an intriguing tool I prepared to identify some key function of the Microsoft (8080,8085,Z80) or Sinclair ROMs. It is able to identify all the clones, from the Altair up to the latest models.. including the RML380Z, the DEC VK100 and many others which surprisingly are Microsoft derivatives.

The current source can be assembled to create a valid MSX 1 ROM but still can't be heavily modified.
I'd like to share my actual results to permit others to study / improve them.

I put a further effort on it, and understood how to decode the final part.
I'm also attaching a crazy example to show it can already be used for simple mods (watch out, it is not yet fully decoded !!).

Regards,

Hans

FIles at http://msx.hansotten.com/index.php?page=msxsw

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Por rolandve

Expert (113)

Imagen del rolandve

29-05-2016, 22:00

Cool, someone might feel like optimising the rom Smile

Por NYYRIKKI

Enlighted (5398)

Imagen del NYYRIKKI

30-05-2016, 02:26

Good luck, this is always good learning experience, but I think it will be very hard to beat the version found in msxsyssrc... Most of the routines are very well documented down to tiny details and it allows you to compile different language versions etc. TBH I would rather see some collaboration & cross checking done than yet another completely new disassembly.

Por rolandve

Expert (113)

Imagen del rolandve

30-05-2016, 08:17

"rather see some collaboration & cross checking..."
I am no long time member of MRC, but I have the impression that the people here are more or less individuals that have their own plans and aim for individual goals.

Por NYYRIKKI

Enlighted (5398)

Imagen del NYYRIKKI

30-05-2016, 22:14

rolandve wrote:

"rather see some collaboration & cross checking..."
I am no long time member of MRC, but I have the impression that the people here are more or less individuals that have their own plans and aim for individual goals.

Yes, in general I'm very much in to this kind of thinking and even encouraging it. How ever MSX-BIOS is not like a bible that you can look and make your own decisions of the meaning for reasons you are after. Although I'm not qualified at all to say that the math as we know it is the absolute truth (actually that would be rather unlikely) I know that the "truth" of Z80-assembly fundamentals and math in general (when MSX-BIOS was written) has not changed during the last 40 years.

This makes me pretty safe to say that one uniform understanding of the original meaning and functionality is very likely to appear if these routines are investigated far enough by individual persons. -> Regardless of the individual goals, collaboration here should give better result for all of the participants.

Por Edevaldo

Master (134)

Imagen del Edevaldo

20-09-2017, 18:22

Maybe a wiki on the dissasembled BIOS could be helpful to foster colaboration. Otherwise the information will continue to be scattered and fruit of individual efforts.

Por Edevaldo

Master (134)

Imagen del Edevaldo

20-09-2017, 19:28

Maybe a GitHub project for those kind of things would be a great way to leverage the efforts. While not including the ROMs, the disassembled source code and tools could be made available. People could check it out and check it in with updated comments. The GitHub wiki page could include extra documentation. It is editable by everybody that has the interest. Version controlled...

It could be a MSX.org root account there and those development individual projects under it.

Por praduca

Supporter (3)

Imagen del praduca

09-04-2019, 10:09

HansO wrote:

Message and files sent to me by Stefano Bodrato.

...

FIles at http://msx.hansotten.com/index.php?page=msxsw

This link appears to be broken, the page section about MSX doesn't exist anymore

Por zeilemaker54

Master (249)

Imagen del zeilemaker54

09-04-2019, 11:27

My msxsyssrc project is already mentioned.
All source files are already in a sourceforge git repository.
At this moment, I am the only contributer to this git repository. But feel free to drop me an email if you want to contribute as well.

Por theNestruo

Expert (112)

Imagen del theNestruo

09-04-2019, 19:24

zeilemaker54 wrote:

My msxsyssrc project is already mentioned.
All source files are already in a sourceforge git repository.

Hi! I've found your disassembly very useful several times. Thank you!!