MODIFY SONY MPF920 DRIVE FOR ATARI USE

General discussions or ideas about hardware.
guus.assmann
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by guus.assmann » Sat Dec 16, 2017 9:02 pm

Yes, it's that way in the Mega ST.
But I like things to be interchangable and standard.
So on my MegaST I did make a cable from the MB pin 2 to the floppy-switch module.
This way I can use the same floppy-drive(s) in any board I use.

BR/
Guus

Bikerbob
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by Bikerbob » Sun Dec 17, 2017 3:31 am

And some of you wonder why I find all these things so confusing?

SO is this the pin 2 mod that Alison did?

guus you use the name Mega ST.. Not STE? I want to be very clear??

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exxos
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by exxos » Sun Dec 17, 2017 4:00 am

i dont know what aly did or if it worked. i would do yourself a favour and stop going on af for information. as i said, my method is easier and tried and tested so i dont understand why you are wanting to do mods which are questionable in the first place. . i would get the drive working before looking towards doing other mods to it.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by exxos » Sun Dec 17, 2017 12:00 pm

A simple mod, not tested exactly this way.. but saves using a IC..

PNP transistor...
connect:

C to 0v (WD pin 14)
B via 1K to MON (pin 20)
E to WP (pin 25)

When MON is high, transistor is off.. When MON is low, transistor turns on, connects WP to 0v.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

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Bikerbob
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by Bikerbob » Sun Dec 17, 2017 3:49 pm

exxos wrote:
Sun Dec 17, 2017 4:00 am
i dont know what aly did or if it worked. i would do yourself a favour and stop going on af for information. as i said, my method is easier and tried and tested so i dont understand why you are wanting to do mods which are questionable in the first place. . i would get the drive working before looking towards doing other mods to it.
In response to your statement about AF - there were three really good sources (how accurate I dont know) for info for atari about a year ago. AF, the AF wiki - which I loved, and Docs.dev.. and the last 2 are now gone for some unknown reason, and very disappointing.

I am sure there are better and great sources in German, but I cant read or write german.

I am glad for this forum because it is another source, but that was why Wikipedia became so popular was because I could post something and 10 others could add change and update it. If the only issues with those last two sites was hosting.. cant we as a community do something about that??

I would much rather get my information from a wiki that I know many people are contributing to to help keep it updated and accurate than forum posts from 2-5-10 years ago, wondering what is current, what is right, etc...

The 920 that I did the ID mod on, works, it does make a hard clunk sound (not the drive head engaging the disk) - might be the heads 0ing.. maybe.. but otherwise it works. All I am worried about now is making sure when I change disks I dont get corruption because it did not sense the media change. As far as I am aware.. with the MEGA STE the density detect is not an issue, as long as it knows what media is in there.. makes sense to me.

So if your transistor mod if for media change I will try that. You said something about a program? to test? I am willing to do that as well.

James

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exxos
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by exxos » Sun Dec 17, 2017 5:12 pm

Bikerbob wrote:
Sun Dec 17, 2017 3:49 pm
I am glad for this forum because it is another source, but that was why Wikipedia became so popular was because I could post something and 10 others could add change and update it. If the only issues with those last two sites was hosting.. cant we as a community do something about that??

I would much rather get my information from a wiki that I know many people are contributing to to help keep it updated and accurate than forum posts from 2-5-10 years ago, wondering what is current, what is right, etc...
I host a lot of stuff. Though wiki has been broken for some time. But problem is, like my work, so many people against it, take DMA work for example, wiki says -38 evil, I say otherwise, if I updated wiki with my work, it would rain hell on my door. So for me, wiki isn't useful for latest work. Community is broken big time, so I start this forum, to start again, with tested solutions and facts. So AF and AF wiki, things of the past. Its time to move on.
Bikerbob wrote:
Sun Dec 17, 2017 3:49 pm
The 920 that I did the ID mod on, works, it does make a hard clunk sound (not the drive head engaging the disk) - might be the heads 0ing.. maybe.. but otherwise it works. All I am worried about now is making sure when I change disks I dont get corruption because it did not sense the media change. As far as I am aware.. with the MEGA STE the density detect is not an issue, as long as it knows what media is in there.. makes sense to me.

So if your transistor mod if for media change I will try that. You said something about a program? to test? I am willing to do that as well.
The GAL code works, I use it in my V6 mod, transistor is just that part, no reason why not to work. If you test and verify, then we will sort out a good guide for people who want to do mod in future. As you know, otherwise, just total confusion. So need to get good information here, tested and verified current work. This is whole idea of this forum.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

Bikerbob
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by Bikerbob » Mon Dec 18, 2017 2:04 am

Ok, sounds good. I have the drive apart. Painting the faceplate tonight.

I will try the mod tomorrow or tuesday. But how do I test? I need a control and then do the mod. I will mod one of the other 920s with the ID.. not sure how to verify if the transistor is making the difference.

James

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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by exxos » Mon Dec 18, 2017 11:41 am

Bikerbob wrote:
Mon Dec 18, 2017 2:04 am
I will try the mod tomorrow or tuesday. But how do I test? I need a control and then do the mod. I will mod one of the other 920s with the ID.. not sure how to verify if the transistor is making the difference.
viewtopic.php?f=12&t=428#p2797
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

Bikerbob
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by Bikerbob » Mon Dec 18, 2017 3:09 pm

Thanks Chris, I will do that today.

So in fact, this is not a modify of the drive at all, its a modify of the media detect in the computer. SO for the drive, as long as I use one that I can do the ID jumper change, on my mega STE this mod will make it re-read every time a new access.

I suppose a little slower? but so what.. never an issue with wrong write.

James

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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by exxos » Mon Dec 18, 2017 3:14 pm

Bikerbob wrote:
Mon Dec 18, 2017 3:09 pm
So in fact, this is not a modify of the drive at all, its a modify of the media detect in the computer. SO for the drive, as long as I use one that I can do the ID jumper change, on my mega STE this mod will make it re-read every time a new access.
I thought it would be better to do this on the computer, as if you needed to swap drives a lot, then you would have to mod every single drive which would be a nightmare. So just modifying the computer just a lot easier and of course the WD1772 is pretty generic across all motherboards. To do a guide every floppy drive out there could be bit of a nightmare..
Bikerbob wrote:
Mon Dec 18, 2017 3:09 pm
I suppose a little slower? but so what.. never an issue with wrong write.
I don't understand what you are referring to here..... ?
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

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