Games that work on MSX2, but not on MSX2+

Page 3/3
1 | 2 |

By hit9918

Prophet (2905)

hit9918's picture

26-05-2014, 17:27

step by step.
first MSX2 comes with RAM in subslot.
then MSX2+ comes with bios in subslot.
to make two generations of problems Tongue

By mars2000you

Enlighted (5984)

mars2000you's picture

26-05-2014, 17:43

Bios in subslot exists also on MSX2 : Arabic and Korean machines, Victor HC-90/95/95A, Sony HB-G900(A)P, National FS-4500/4600/4700 and more ....

By hit9918

Prophet (2905)

hit9918's picture

26-05-2014, 17:44

another thing:
bios slot toggeling updates SLTTBL secondary slot register mirrors.
under DOS2 I found such code, too.

strictly speaking you must update the SLTTBL mirror whenever you write FFFF.
these two writes must go while disabled interrupts to make them atomic.

the typical "where am I" getslt code using FCC5.
typicaly works because the ROM asks where it is before doing RAM search.
but using the function again after the typical RAM search that not updates FCC5,
things can go wrong in an ugly way not easy to detect.

high speed things could still do correct when keeping interrupts disabled as long as FCC5+ is not in sync.

By NYYRIKKI

Enlighted (5873)

NYYRIKKI's picture

26-05-2014, 18:02

hit9918 wrote:

step by step.
first MSX2 comes with RAM in subslot.
then MSX2+ comes with bios in subslot.
to make two generations of problems Tongue

Well... Now that we have this wonderful thing called internet, it is easy to prove that the specs were there from the day one... too bad they forgot to tell these things to software manufacturers... Also, if you ask me the whole idea of memory mapped individual sub-slot select registers should have been killed and buried long before the standard was even established... It was very bad idea from hardware to software, but now we just have to live with these limitations.

By hit9918

Prophet (2905)

hit9918's picture

26-05-2014, 19:24

I blame it on software, not on hardware.
Be it lack in bios software, be it lack of docs with example codes.

The secondary slot register hardware is genious in that it needs zero chips on MSX1. No single resistor.
And then the machine with just a 8255 has 16 slots.
Because subslot gear is "on the cartridge".

By gdx

Enlighted (4693)

gdx's picture

07-06-2014, 11:28

Desolator updated !

- Works on a secondary slot (I think)
- Works on HB-500

MSXgamesFix.zip (This is the alternate version)

Page 3/3
1 | 2 |