MODIFY SONY MPF920 DRIVE FOR ATARI USE

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

Post by Zarchos » Thu Dec 14, 2017 4:24 pm

I don't get it.
It is an HD floppy drive.
You do not need any additional modding to have it work on the Atari ST ?
To work on the Archies which can only have DD (that's all models before and including the BBCA3000), we need to solder a wire, and cut one track here or there.
If interested, I can post the links here.
Here it is :
http://www.stardot.org.uk/forums/viewto ... 920#p90351
you can use the search engine with mpf920, there might be more possibilities depending on the version of the MPF920

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exxos
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by exxos » Thu Dec 14, 2017 4:28 pm

Zarchos wrote:
Thu Dec 14, 2017 4:24 pm
I don't get it.
It is an HD floppy drive.
You do not need any additional modding to have it work on the Atari ST ?
To work on the Archies which can only have DD (that's all models before and including the BBCA3000), we need to solder a wire, and cut one track here or there.
If interested, I can post the links here.

You cannot take a PC drive and have it work on the Atari, have to change the drive select ID for it to work. To get it working with high-density disks need the upgrade to the floppy controller circuit like the ones I sell in my store. This is all really old knowledge and is pretty standard stuff.
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
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Zarchos
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by Zarchos » Thu Dec 14, 2017 4:29 pm

exxos wrote:
Thu Dec 14, 2017 4:28 pm
Zarchos wrote:
Thu Dec 14, 2017 4:24 pm
I don't get it.
It is an HD floppy drive.
You do not need any additional modding to have it work on the Atari ST ?
To work on the Archies which can only have DD (that's all models before and including the BBCA3000), we need to solder a wire, and cut one track here or there.
If interested, I can post the links here.

You cannot take a PC drive and have it work on the Atari, have to change the drive select ID for it to work. To get it working with high-density disks need the upgrade to the floppy controller circuit like the ones I sell in my store. This is all really old knowledge and is pretty standard stuff.
See the link in my edited message ;-)
Your HD drive becomes DD ;-)

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exxos
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by exxos » Thu Dec 14, 2017 4:31 pm

Zarchos wrote:
Thu Dec 14, 2017 4:29 pm
See the link in my edited message ;-)
Your HD drive becomes DD ;-)
You don't need to mess about forcing DD modes like this on the Atari... That is just unnecessarily creating more work and confusion..

Also pin 34 isn't even used on the Atari so the link doesn't have any relevance to this anyway...
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.

Petari
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by Petari » Thu Dec 14, 2017 4:33 pm

Every HD drive can 'become' DD. What's the point in pointing on it ? :mrgreen:

Zarchos
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by Zarchos » Thu Dec 14, 2017 4:34 pm

exxos wrote:
Thu Dec 14, 2017 4:31 pm
Zarchos wrote:
Thu Dec 14, 2017 4:29 pm
See the link in my edited message ;-)
Your HD drive becomes DD ;-)
You don't need to mess about forcing DD modes like this on the Atari... That is just unnecessarily creating more work and confusion..

Also pin 34 isn't even used on the Atari so the link doesn't have any relevance to this anyway...
Ah ok.
Good to know.
The Atari machine is then very interesting, as the mod described is also what they do for many other machines, like MSX and MSX2s ...
Well, letting the infos here will allow readers to know just ... what they don't need to do ;)

Zarchos
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by Zarchos » Thu Dec 14, 2017 4:35 pm

Petari wrote:
Thu Dec 14, 2017 4:33 pm
Every HD drive can 'become' DD. What's the point in pointing on it ? :mrgreen:
On the Atari machines yes.
Not for the others.
Always interesting for readers who could be confused reading one 'general' solution on the Net, and then another one given here,
to understand it is much easier for their Ataris :D

Now the moderator can of course delete all these posts if he considers they are not helpful. ;)

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exxos
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by exxos » Thu Dec 14, 2017 4:50 pm

It is worth noting that a lot of these modifications seem to come from the Amiga community, where they use pin2 and pin34 , it looks like they are swapping the lines, but I have not looked into this much. I should make it clear that these lines are not connected on the Atari motherboard so any these such modifications are totally useless on the Atari.

I think it is clear there is multiple ways of modelling these drives to work on various machines. Though overall we should really stick to Atari stuff this particular thread :)
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.

guus.assmann
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by guus.assmann » Thu Dec 14, 2017 8:57 pm

Reading these posts, and others about Floppy drives did help me.
I had not realised that pin 2 on a floppy-drive can also be an output.
On some PC-drives it is.
On one Sony drive, I had to cut a trace from pin 2 and connect the internal trace to the density switch.
Than invert that signal and connect it to pin 2 again, so this pin is now an output and switches the clock speed.

BR/
Guus

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exxos
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Re: MODIFY SONY MPF920 DRIVE FOR ATARI USE

Post by exxos » Thu Dec 14, 2017 10:06 pm

guus.assmann wrote:
Thu Dec 14, 2017 8:57 pm
Reading these posts, and others about Floppy drives did help me.
I had not realised that pin 2 on a floppy-drive can also be an output.
On some PC-drives it is.
On one Sony drive, I had to cut a trace from pin 2 and connect the internal trace to the density switch.
Than invert that signal and connect it to pin 2 again, so this pin is now an output and switches the clock speed.
Assume you are talking about the MSTE here ? ST's don't use pin 2 for anything.. and only seen Amiga guys using pin 2..
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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