Are we sure that VG-8235 is not upgradable to 2plus?

Paladin (813)

05-05-2014, 12:55

I heard that my VG-8235 with 720k drive couldn't be upgraded to MSX2+.
Then I see this Wiki where the 8245 seems to have the same chip of VG8235.
Then I've seen many posts about 8245 upgrade to MSX2+
My question now is:
Can I upgrade my VG-8235 to MSX2+ ??
Which parts Have I to use?
Where could I find them?
What about instructions to make this upgrade?

Regards

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By Poltergeist

Champion (280)

05-05-2014, 13:23

My VG8235 with 720KB was upgraded to 2+ when I wore a younger man's clothes, so it sure is possible. I just don't know how, as it was done for me, not by me...

By Jipe

Paragon (1625)

05-05-2014, 13:51

yes you can but many model of 8235

http://www.msxvillage.fr/forum/topic.php?id=475&pt=3

By giuseve

Paladin (813)

05-05-2014, 17:57

@Jipe

thanks! I don't speak french, but maybe I understood that I need the same kit necessary for NMS-8250.
It would be great to find any resourse in English (I've also many problems with Dutch that seems to be the more used language for MSX-Tuning instructions :-) )

By Jipe

Paragon (1625)

05-05-2014, 18:20

my taylor is rich but my english is poor
try google for translate

whith a 8235/39 you need an eprom 64k + an eprom 16k solder on

By mohai

Paragon (1031)

22-05-2014, 11:25

From the schemes, as far as I understood, the extra ROM is needed to show logo up, as Philips lacks of Kanji roms where the logo is in MSX 2+.
Is the extra logo ROM modified in any way to match keyboard or bypass F4 register?

I have a 8245 modified to MSX2+ but it does not show logo. It does not have F4 register.
Can i use that ROM to add logo screen?

By l_oliveira

Hero (534)

23-05-2014, 03:28

Use SUBROM from Brazilian DDX 2+ kit. That is modified to aways show MSX logo regardless of F4 port state (DDX kit has no F4 port) Also while it has Kanji driver inside the subrom, it's disabled.

By mohai

Paragon (1031)

23-05-2014, 11:41

@Jipe:
I have a 8235/00.
It has 3 EPROM chip on it: BASIC+BIOS, MSX2-EXTENSION and FDD-BIOS (IIRC)
FDD BIOS is 16KB DISKROM.
Will it work If I replace DISKROM chip with a 32 KB one with DISKROM and extra LOGO-ROM?
AFAIK, that LOGO-ROM start address is 0000, so it could fit with DISKROM in one chip.

By l_oliveira

Hero (534)

23-05-2014, 15:09

NOT LOGOROM. SUBROM is a LOT more than that.

And MSX2+ subrom is not 16KB is 32KB because kanji driver is part of it. IF you remove kanji driver without "fix" the stuff missing the computer will not work right.

By NYYRIKKI

Enlighted (6091)

23-05-2014, 19:50

I've managed to squeeze all important MSX2+ features back to 16K so that you can upgrade practically any MSX2 by just replacing the VDP and replacing the ROMs. No need for jump wires in motherboard... Some things had to go such as KANJI related stuff, "M" & "S" from the logo etc. but I also added frequency selector.

See here

By l_oliveira

Hero (534)

23-05-2014, 19:44

How does frequency selection works NYYRIKKI ?