Disable only internal drive DOS1 ?

By retrocanada76

Champion (480)

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23-02-2020, 04:05

HI, is there any program to disable the internal drive ?

I got a EmuFDC but in systems with internal drive like CF-3300 I cannot get enough TPA for some games. Pressing CTRL will still initialize the internal FDD and SHIFT will disable both.

I believe such a program would go to basic do some magic and return to dos.

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By gdx

Prophet (3312)

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23-02-2020, 08:16

If you replace or rewrite the IC3 (27128) of the FDD board with one of the two Disk-Rom below, you will be able to disable it by pressing BS key at startup.

Download: https://mon-partage.fr/f/h1cSpamD/

This Rom seems use a socket so no need to solder.

Disk-Rom from the CF-5500 is probably the same that was updated. So I think you can use it. Make a backup of the original Rom before proceeding.

By retrocanada76

Champion (480)

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23-02-2020, 10:50

Ow that's good. I have spare 27C128's here.

I'll try it.

i compared the roms with the 3300 original one and this one is just the addition of 2 hooks checking the (FBE2) bit 3.

Thanks

By retrocanada76

Champion (480)

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24-02-2020, 07:25

It works fine except that is actually DEL button not BS.

Thanks

By gdx

Prophet (3312)

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24-02-2020, 09:31

Sorry, if you prefere BS, replace "3A E2 FB CB 5F" by "3A E1 FB CB 6F" at 03F40h and 03F50h.

Which Rom did you use?

By sdsnatcher73

Paladin (799)

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24-02-2020, 11:24

@gdx: that is a nice mod. Do you have it also for NMS8245 (preferably 1.08 version)?

By gdx

Prophet (3312)

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24-02-2020, 11:55

Where is this version available?

By sdsnatcher73

Paladin (799)

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24-02-2020, 12:42

It’s in the systemroms.zip on msxarchive.nl as a 64kB EPROM dump (last 16kB is the disk ROM).

By retrocanada76

Champion (480)

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24-02-2020, 22:35

I used the 3300 version as I compared it to my version and only the hooks changed. I'm totally fine with DEL. Just to clarify as I pressed BS and it didn't work Big smile

By gdx

Prophet (3312)

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24-02-2020, 23:50

Here is the version for the NMS-8245:
https://mon-partage.fr/f/aOhqgrtw/

By sdsnatcher73

Paladin (799)

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25-02-2020, 20:02

Thanks gdx! Working great!