LOGI-BAL Emulation

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By JaccoPK

Supporter (9)

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10-03-2012, 23:56

Got it thx. Its nice to see such old stuff still work!

By JaccoPK

Supporter (9)

JaccoPK's picture

11-03-2012, 07:11

Didn't hit the copy protection yet we built in. Maybe emulators handle it properly :-)

As I remember it worked as follows:

- the disks were copied/created on special diskdrive hardware
- this hardware wrote to sectors only this hardware could reach for writing (all normal drives could read them)
- the code to check the contents of these sectors is loaded into VIDEORAM by the game
- a logical operation on the VIDEORAM makes this code runnable
- the code is then copied to several places in de main code on initialization
- on several levels changes one such routine is executed
 
I believe at level 10 a more stringent version was also in place.

Regards, Jacco

By Manuel

Ascended (18864)

Manuel's picture

11-03-2012, 09:44

JaccoPK: any copy protection scheme that works with weird disk formats is not supported by any emulator at the moment... yet!
So, maybe it was removed when the game was donated to MCCM?

By NYYRIKKI

Enlighted (5939)

NYYRIKKI's picture

11-03-2012, 14:24

I think rMSX emulator can handle this kind of protection if the disk is correctly dumped or if you use original disk. (MSX2 emulator for MSX tR) How ever I don't know what disk dump tool would make image of this kind of disk correctly.

(This was my post 2222, Not bad Smile )

By mars2000you

Enlighted (6260)

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11-03-2012, 22:57

I've made some tests on blueMSX 2.8.3 beta.
LOGI-BAL does not require DOS2, you can also use DOS1.
With DOS1, no any problem on blueMSX.
With DOS2, there is indeed a problem with MEMMAN if you run MSX2 or MSX2+ machines; on TurboR, no any problem.
I guess there is an accuracy problem in the MSX2/MSX2+ emulation.

By Manuel

Ascended (18864)

Manuel's picture

11-03-2012, 23:20

JaccoPK: can you explain how I can reproduce that wrong level and graphics thing? I couldn't reproduce that with my disk image.

By edoz

Prophet (2443)

edoz's picture

14-03-2012, 21:21

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