Switch between MSX2 mode and MSX 2+ mode

Prophet (2501)

08-05-2011, 23:29

I have a MSX 8280 that is upgraded somewhere in the ninetees ..
Also Somewhere in time i changed the front of the MSX. (Because it was newer and had a better look) on the old front it was possible to switch to MSX 2 mode or MSX 2+ mode. Also it was possible to enable 7 Mhz or not. For some reason i don't now why i never created this switches on the new front of the MSX. But i like to do it now.
I'm not a hardware specialist .. but i need to know where i need a switch to swap between MSX 2 or MSX 2+ .. is this possible ?
Does someone know where to connect the wires in the mainbord. Is it also possible to enable or disable FMPAC.
I know already where to find the pins for switching between 3 Mhz and 7 Mhz..

See Images from the MSX8280 mainboard. If you need more pictures from a special location let me know.

Thanks so far.

members.home.nl/evanzanten/MSX8280.JPG

!login ou Inscrivez-vous pour poster

Par meits

Scribe (6573)

09-05-2011, 06:37

It is possible, so I was told when my MSX got 2+'ed. But the question 'Why would you want that' was asked in the same breath.

Par Daemos

Prophet (2170)

09-05-2011, 09:39

Question about the photo: Why did someone scratch the numbers of the IC's and especially only the serial and production number of the FM chip?

Par Huey

Prophet (2696)

09-05-2011, 09:45

Question about the photo: Why did someone scratch the numbers of the IC's and especially only the serial and production number of the FM chip?

IIRC it was standard procedure for MSX club Gouda. Afraid someone would copy the design and they would make less money.

Par Repair-Bas

Paragon (1176)

09-05-2011, 10:41

It is 100% sure that this computer was modified by msx-club gouda.

It is not possible anymore to switch to msx2, because there are only msx2+ rom in this computer

Par Huey

Prophet (2696)

09-05-2011, 11:02

It is 100% sure that this computer was modified by msx-club gouda.

You're right. I cannot know for sure.

Par Daemos

Prophet (2170)

09-05-2011, 12:04

It is not possible anymore to switch to msx2, because there are only msx2+ rom in this computer

Is it not possible to design a cartridge that does this, holding the ROMS etc?

Par luppie

Paladin (869)

10-05-2011, 00:38

I would love to have the design of the FM-Pac PCB, still have some spare YM2413's to build in some MSX's
The 8 pin IC must be a simple OPAMP, so could'nt be to hard to rebuild it.

Par edoz

Prophet (2501)

10-05-2011, 08:27

Repair-bas ,are you sure there are no MSX 2 roms anymore ? because the 3 big ones (i'm not a hardware guru) are 6 .. You cannot see this on the picture because the picture is taken from above. There a 3x2 roms overthere.

Luppie, I have no design of the FM-Pac but if you want i can make more pictures ?

Par edoz

Prophet (2501)

10-05-2011, 08:37

members.home.nl/evanzanten/MSX8280-2.JPG

Par NYYRIKKI

Enlighted (6093)

10-05-2011, 10:27

Indeed it seems that the ROM's can be changed. This is controlled by the 2x2 gray wires connected abowe texts IC119 and IC118. How ever from the picture it does not come clear to me where those wires go or how the logic works after that.