Undocumented Mode 1 + 2 : Poll/Discussion | MSX Resource Center (Page 2/4)

Prophet (2200)

27-02-2007, 19:11

Sounds like its quite common to use mirroing so then I don't think its anything to worry about. I read the karoshi forum and some people doesn't really like using it but I don't think there are any good arguments not to use mirroring. I think its more interesting to use the full capacity of the MSX1 so I don't think its a problem if a few MSXes is not able to run a game using mirroring. Its like banning all MSX games that uses more than 8kB ram

Par ARTRAG

Enlighted (6931)

27-02-2007, 19:23

I agree. I use mirroring as well, (there are tons of things that you cannot do in other ways).
I hope MSXDEV wont disqualify me

I was interested in the MSX's that do not support it (or better support it but get sprite mirroring as side effect).

a) Is the mirroring of the PCT, of the PGT or of both that generates sprite mirroring as side effect ?

b) Is sprite mirroring the only reason why mode 1+2 sould be avoided or there are some VDP's that does not support
the mirroring at all?

Par dvik

Prophet (2200)

27-02-2007, 19:35

I read the karoshi topic and my Spanish is not so good but if I understand correctly the mirroring does not work at all on some early Sony machines, HB-20P for example. On these machines it sounds like only the top 1/3 of the screen will be shown correctly. But it sounds like its not a problem on all HB-20P machines.

I'm also very interested to hear more about question a. Would be great to know the answer to these more specific questions (same as yours ARTRAG but more explicit):

1. Does PCT mirroring cause sprite mirroring side effects?
2. Does PGT mirroring cause sprite mirroring side effects?
3. Does PCT+PGT mirroring cause sprite mirroring side effects?

Par dvik

Prophet (2200)

27-02-2007, 19:37

I don't have a HB-20P but it would be interesting to see if the GnG demo also fails on the machines that failed Ramones test programs. Anyone that has one of the failing sony machines willing to give it a try?

Par jltursan

Prophet (2619)

27-02-2007, 21:24

Not only the new batch of Sony machines (HB-20 and maybe even the rest of the family, HB-10, HB-201,etc); but also the Toshiba machines seems that they dislike this mirroring. Sadly none of my machines are the offeding ones... ...or maybe

Par PlainSpooky

Resident (53)

28-02-2007, 02:20

ARTRAG:

Try looking the main program "FDBENCH.BAS".

Par Manuel

Ascended (19299)

28-02-2007, 21:14

Do those machines have a different type of VDP? Is there a list of machines with such a VDP?

Is "VDP Pirates" also one of the programs that fails? (I remember someone said it wouldn't work on a Toshiba HX-10.)

Par dvik

Prophet (2200)

28-02-2007, 21:24

what tricks does VDP Pirates use?

Par jltursan

Prophet (2619)

28-02-2007, 21:53

It uses the standard SC0 mode, just some screen splits to change the pattern table and color register. As it's heavily synchronized (without sprites ) any external hardware plugged that uses interrupts could mess the splits; but the VDP type doesn't matter.

The machines that have been reported as "weird" (all of them seems to have the Toshiba VDP) are:

Toshiba HX-10
Toshiba HX-20
Sony HB-10P

But there're some few reports that talk about having such computers and testing sucessfully the mirroring....maybe some cheap T6950 revision?

A close picture of a Sony HB-10P taken by Viejo archivero

Par dvik

Prophet (2200)

28-02-2007, 22:03

It would be very interesting to see the Sudoku game running on these machines. The black and white intro is also screen 0 and using heavily synchronized code. Would be very interesting to hear if that part fails running on the machines you mention.