HB-F1XD Japanese MSX2 - Replace V9938 with V9958?

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By Colemu

Hero (535)

Colemu's picture

13-09-2012, 19:49

no just a cheap one mate, so its a little high.
I'm going to use the Modified Sub ROM NYYRIKKI created for me so that I only need the 3 main ROMs (64kb)

Then I may have space for the 512kb. Extra RAM.
Not a clue how to attach the extra RAM but I'll deal with that when I get that far... oO

By Colemu

Hero (535)

Colemu's picture

14-09-2012, 15:31

Update: the Rom I created using NYYRIKKI's modified SUB rom (64k) did not work in the MSX2 using 27C512 (as I stated in a previous post). I put this down to none existence of the V9958.

Whilst waiting for the VDP to turn up, I got bored. Thought I'd try the same 64k rom on my 27C010 as the original rom worked fine in that. What do you know, it works perfectly!!

Now running computer in BASIC 3 !! Things are progressing nicely... Big smile

The feature of being able to boot in PAL mode is very handy too Wink

By RetroTechie

Paragon (1563)

RetroTechie's picture

14-09-2012, 21:38

Then I think you did something wrong writing that 27C512, or plugging it in - did you check pinout & correct position in a 32 pin socket where previously was a 1 Mbit ROM?

Anyway: normally it would go against my grain to upload a system rom I didn't pull from a ROM chip myself, but given how it was done & after checking contents, I'm pretty confident it's the real thing. So here goes: Sony HB-F1XD rom (link is also on MSX sub-page).

It would be interesting to know what all those different RS-232 roms are (in the unused 2nd half), in which machines they're used, features etc. For that reason, I hope this site's operators won't make a fuss concerning their warez policy... ;) Above file is useless for noob emulator users anyway, as emulators use that rom split into smaller blocks like bios/basic/msx2sub etc.

Block ordering is definitely different from Sanyo Wavy FD2 (MSX2+): the 1 Mbit system ROM in there is ordered as: MSX-Music, KUN compiler (page 2 _BC version), MSX2+ page 1 rom, MSX2+ page 2 rom, bios, basic, msx2sub, disk. Don't know about the rom in other Japanese MSX2 machines like Sony HB-F1 or Panasonic FS-A1. Good chance they're the same as for the F1XD.

By Colemu

Hero (535)

Colemu's picture

14-09-2012, 21:40

I may have done, seems strange that it didn't work. Did it the same way that I wrote the original rom however, and that worked fine. oO
At least I know the new BASIC3 rom works now, very handy pressing h and having it boot in PAL mode.
Is there any way of adding MSX DOS 2 to the system?

By RetroTechie

Paragon (1563)

RetroTechie's picture

14-09-2012, 21:44

Maybe a 27(C)512 isn't a plug-in replacement then after all. Wouldn't know why, (EP)ROMs are pretty simple parts conceptually, and timing is rarely critical. Already checked how pinout on the socket would work with a 27C512 in there & didn't see a problem.

Guess I'd have to check on real hw myself, until such opportunity I'll add this to my Question wtf department...

By RetroTechie

Paragon (1563)

RetroTechie's picture

14-09-2012, 21:47

Colemu wrote:

very handy pressing h and having it boot in PAL mode.

Hmm... default is 60 Hz for that modified ROM? Question Doesn't seem handy unless you live in US or JP area.

By Colemu

Hero (535)

Colemu's picture

14-09-2012, 21:53

LOL LOL!

Is the second part possible (adding MSX DOS 2)?
Just in theory at the moment, I'm happy enough that I have a working ROM Big smile

Default is NTSC (60hz), but it boots in PAL if you hold down H (50hz)
Very handy because PAL games now run at the correct speed...

By RetroTechie

Paragon (1563)

RetroTechie's picture

14-09-2012, 22:09

Yes but I meant the opposite: 50 Hz default, and a hotkey for starting @ 60 Hz...

Internal DOS2 is possible, but that's 64 KB + a rom mapper (read: get out another 27C512, and a 2x 74HCTxx circuit to do the blockswitching). This kind of extensive ROM add-ons would be really fun with a big, in-system rewriteable flash rom (say, a 29C040), together with an in-system reconfigurable logic chip to control it (a Xilinx XC9572 for example).

By Colemu

Hero (535)

Colemu's picture

14-09-2012, 23:08

An internal Flash ROM would be absolutely great, we can always dream eh... Wink

I'll settle for a working external rom for dos 2. Haven't managed to do it yet though on my MegaFlashRom SCC

I will re-burn the 27C512 rom as it should work as RetroT says. I must have made an error.
Daft to waste a 1m-bit rom when a 64k will suffice

By Colemu

Hero (535)

Colemu's picture

15-09-2012, 00:01

Yup, must have been a bad burn.

Works fine on a 27C512 oO

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