Well, as most of you know, 2+ weren't manufactured in Brazil. There were a few conversion kits made by Ademir and copied by DDX, but that is all. It is not easy to find a 2+ in Brazil to buy, beyond over-over-overpriced foreign MSX brought by "collectors". But this is another subject.

The question is: Will it blend? Ops, wrong forum!

The real question is: Me and Ricardo Sartorato found a way to convert the old DDX (and therefore, the AC88) MSX 2 conversion kits to 2+, changing the ROMs, the VDP and adding the #F4 register. Ricardo went further, finding a ROM that doesn't need the F4 register (and neither the clock!) so now anyone with access to an EPROM burner and a 9958 can convert his/her kit to 2+. Great.

But with the new ROMs, and without the F4 register board, there is no MSX logo on bootup. Duh.

I tried to hack the RDBTST (Read value of I/O port #F4) directly into the BIOS, changing the original code

RDBTST: in (#F4),A
cpl
ret

into:

RDBTST: ld a,0
nop
ret

And it didn't worked on BlueMSX. I tried to load FF instead of 00, but nothing happened. I have no listing of the MSX Bios (this code was taken from a disassembly using IDA PRO) and don't know how the boot process of 2+ computers works. Anyone could give a little help here?

Thanks,
Alexandre
http://www.tabajara-labs.com.br

Hi, mabye a bit off-topic, but why don't you replace the EEPROM with flash rom. Using flash rom, you don't need to remove the rom from the pcb to program it and you don't need a programmer. It's much more flexible and it's around the same price as an EEPROM. I used the following AMD flash rom:

nl.farnell.com/jsp/search2/browse.jsp?N=500029&Ntk=gensearch_001&Ntt=4411535&Ntx=&_requestid=166078

I have an eprom emulator I can update the contents of the rom and reset the msx remotely

Found the problem. The logo is in the KANJI ROM, and brazilian computers has no KANJI ROM.

Now I just need a way of putting this logo into the SubROM

Thanks you all!