NMS8250/16 BIOS

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Door JeroenTaverne

Resident (37)

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24-02-2022, 04:36

Hi. I am looking for the BIOS file of a NMS8250/16. It is a Spanish machine. I would like to temporary change my /00 to Spanish for testing my keyboard interface with a Spanish USB keyboard.

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Van friguron

Master (186)

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25-02-2022, 00:38

Mine is a Spanish 8250/16...

"What should I do" to dump the BIOS roms? (I could write a program to do it, but I feel lazy and I'm sure there are BIOS rom dumper tools around). I have GR8NET as a "power cartridge" to run those alleged "dump tools" in case it's needed.

OTOH, aren't these BIOS probably dumped in openmsx romsets already?

BTW, and OTOH2, if those IC's are socketed (I think they are? can't remember), I could remove and dump them with my TL866 IC programmer... Should be an easier path...

Anyway I won't have the time to do it next weekend, but we might keep in contact the following days in case anyone else hasn't answered your message before I reach my 8250 next week.

Greetings

Van sdsnatcher73

Prophet (3221)

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25-02-2022, 08:54

Check the first post on this thread. You can use SAVEROM is the package. Best is to dump full slots, so 0-0 0x0000 upto 0xFFFF. Same for slot 3-0, 3-1 and 3-2. Then we also have all the info needed to add this machine to openMSX (a lot is already known about 8250).

Van JeroenTaverne

Resident (37)

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25-02-2022, 11:57

Thanks. Unfortunately the utilities/SAVEROM link isn't working.

Van sdsnatcher73

Prophet (3221)

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25-02-2022, 12:09

I just tried it and it is working for me.

Van friguron

Master (186)

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02-03-2022, 03:05

Hi, here I have the result of the ripping

https://www.dropbox.com/s/8v2s9mhbvtusse5/8250_16_spanish_bi...

This should be the result of ripping my 8250/16 (Spanish) MSX2.

The contents of the file are:

-slot 0 -> /S detected pages 0 and 1, so that's what I copied
-slot 3.0 (extended bios) -> /S detected 4 pages so I copied them into a 64KB file, but expectedly all 4 of them are the same 16KB one mirrored. Crop the 64 KB's file into a 16KB's one as needed.
slot 3.3 (disk bios) -> again /S detected 4 pages, but its contents IN MY 8250 are 99,99% 0xFF's and then some alleged status bytes. Why? Because I removed the disk.rom physical IC as my actual real disk drive broke and then I decided I didn't need to waste precious memory trying to support a non existing disk drive.

If something is unclear or even not correct, please ping me back and I'll try to adapt to your needs.

Greetings!

EDIT: BTW, I'm now curious about checking if/how those /16 roms differ somewhat with the 8250/00 ones that are the ones coming with OpenMSX (?)

Van JeroenTaverne

Resident (37)

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05-03-2022, 19:42

Thanks a lot. The keyboard layout of the /16 is different and I am trying to translate the layout of a Spanish USB keyboard to the /16 layout with my USB keyboard interface.

Van Manuel

Ascended (18783)

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05-03-2022, 23:59

Thanks friguron, I added the configuration for this machine to openMSX Smile

Van friguron

Master (186)

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06-03-2022, 04:43

I've just double checked all the checksums of the new "8250_16.xml" file that Manuel pushed onto OpenMSX github some hours ago. They all seem OK with my local unprocessed copies!

I've also binary compared (side by side) the /16 different files with the "core base" /00 ones.

1.- There are expected changes in the BIOS (some key mappings and behaviours in the keyboard routines), as well as some isolated byte at the beginning.
2- There is JUST ONE BYTE of difference in the Extended BIOS. (Who knows why Smile )
3.- There is some (seemingly) rubbish debris at the very end of the /16 BASIC.ROM file, compared with the /00 version which has all 0's.

But now I have a doubt... If I use OpenMSX launching a good and trusted 8250 session (my typical emulated machine) OpenMSX was emulating the /00 "international" version until today... But then "what was the magic behind" the emulated local PC keyboard mapping/behaviour?
I mean, if I press the Ñ key in my local PC keyboard, OpenMSX does some magic to make this Ñ appear on the emulated MSX screen ("emitting" some CODE N ?)
I have to say this is a welcome behaviour, but does it make any sense while using the international /00 ROM? I mean, what will happen within OpenMSX now that the two 8250 variants live side to side at .rom level? Is my local PC keyboard Ñ press behaviour in OpenMSX a "high level" one? or a "Bios controlled" one ?
(Just curiosity)

Van sdsnatcher73

Prophet (3221)

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06-03-2022, 09:24

You have different keyboard mapping strategy in openMSX. There is KEY, CHARACTER and POSITIONAL. If you change to positionL you will notice the behavior most similar to the real hardware. CHARACTER is in general most useful imho. In that mode the character typed on the PC is referenced to the corresponding keyboard matrix on the emulated MSX and openMSX will activate the required lines on the matrix. Pretty smart stuff if you ask me Wink

Van friguron

Master (186)

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06-03-2022, 14:51

But then, is OpenMSX aware of the different keyboard layouts somewhat? (I suppose it is) How come is OpenMSX aware of the actual phyisycal different keyboard matrices of (for example) Ñ keyboards? (Just random thoughts)

As far as I've seen the new 8250/16 .xml file that Manuel defined in OpenMSX github last commit, the file has no mention to any key remapping for this machine...

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