Yamaha MSX2 upgrade | MSX Resource Center (Page 2/2)

By alexito

Paladin (761)

06-05-2018, 01:32

Thanks Alexey and Nyyrikki for this fabulous news I wanna give a try when I have some spare time for sure.

By Wierzbowsky

Guardian (3571)

06-05-2018, 14:43

I made the option to use the selector between the old Subrom and the new one. Pin1 (A15) is connected either to +5V or GND. Ideally there should be a switch accessible from outside, but I got lazy.

By alexito

Paladin (761)

06-05-2018, 16:50

Bravo Alexey. That's a good idea.

By mohai

Paladin (1004)

12-05-2018, 21:10

I see you used an EEPROM chip.
Is it possible to erase and write directly on board?

By Wierzbowsky

Guardian (3571)

13-05-2018, 01:54

I doubt that it's possible to change anything on-the-fly without caching the system ROMs in RAM. And that may not be even possible. Besides, the programming voltage for this chip can't be supplied from the mainboard. So only the EEPROM programmer can do the job.