Emulating an Exatron stringy floppy with a gotek?

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z23
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Joined: Fri Aug 23, 2019 6:03 am

Emulating an Exatron stringy floppy with a gotek?

Post by z23 »

Well, this will certainly be an obscure one, but anyone working on or know if a gotek drive could replace the old exatron drive? I have an old sequential cirtcuits prophet 10 that saves patches to this drive but wondering if it’ll be possible to modernize the thing.

z23
Posts: 26
Joined: Fri Aug 23, 2019 6:03 am

Re: Emulating an Exatron stringy floppy with a gotek?

Post by z23 »

I've attached a schematic I found... I wonder if this would be as easy as the quick disk emulation? I would be willing to test the hardware side of things :)
Attachments
exatron.jpeg
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Jeff
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Re: Emulating an Exatron stringy floppy with a gotek?

Post by Jeff »

z23 wrote:
Thu Sep 19, 2019 7:04 pm
I've attached a schematic I found... I wonder if this would be as easy as the quick disk emulation? I would be willing to test the hardware side of things :)
Have you a schematic with a better resolution ?

z23
Posts: 26
Joined: Fri Aug 23, 2019 6:03 am

Re: Emulating an Exatron stringy floppy with a gotek?

Post by z23 »

Well, here is the source file I found, it was much larger file that I could upload here. It is a little difficult to read, but I think the pinout is the most important, correct? Also, ignore the power supply since this schematic is for a different device all together. The prophet 10 will have a 5v tap for sure to pull from somewhere.

Link:
https://c1.staticflickr.com/4/3787/3243 ... 5435_o.jpg

z23
Posts: 26
Joined: Fri Aug 23, 2019 6:03 am

Re: Emulating an Exatron stringy floppy with a gotek?

Post by z23 »

The Prophet 10 service manual is a little convoluted... the only page I could find skimming through dealing with the tape drive can be seen in the below link. It is attached to the sequencer board.

Prophet 10 Schematic Sequencer board (to tape output)
https://www.dropbox.com/s/gai0mrtd5sef8 ... e.jpg?dl=0

Jeff
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Re: Emulating an Exatron stringy floppy with a gotek?

Post by Jeff »

This seems quite simple. Have you the hardware and the necessary stuff to take some signal captures ?

z23
Posts: 26
Joined: Fri Aug 23, 2019 6:03 am

Re: Emulating an Exatron stringy floppy with a gotek?

Post by z23 »

Jeff wrote:
Fri Sep 20, 2019 7:35 am
This seems quite simple. Have you the hardware and the necessary stuff to take some signal captures ?
Hi Jeff thank you for your reply, I have an oscilloscope and a digital multimeter that performs quite a few functions. Is there anything else I may need?

z23
Posts: 26
Joined: Fri Aug 23, 2019 6:03 am

Re: Emulating an Exatron stringy floppy with a gotek?

Post by z23 »

Here are some pictures of the actual drive:
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IMG_3543.jpeg
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IMG_3542.jpeg
IMG_3542.jpeg (187.15 KiB) Viewed 182499 times

z23
Posts: 26
Joined: Fri Aug 23, 2019 6:03 am

Re: Emulating an Exatron stringy floppy with a gotek?

Post by z23 »

more pics:
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IMG_3546.jpeg
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z23
Posts: 26
Joined: Fri Aug 23, 2019 6:03 am

Re: Emulating an Exatron stringy floppy with a gotek?

Post by z23 »

last one:
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z23
Posts: 26
Joined: Fri Aug 23, 2019 6:03 am

Re: Emulating an Exatron stringy floppy with a gotek?

Post by z23 »

Last thing, I've found and marked all 20 pinouts from this sequencer board to the Exatron drive in red for easy reference. A new high quality file can be downloaded here: https://www.dropbox.com/s/062jg5g1o9bug ... 9.jpg?dl=0

Otherwise a low res is below:
Attachments
prophet10diskdrive(p901 Locations).jpeg
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Jeff
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Re: Emulating an Exatron stringy floppy with a gotek?

Post by Jeff »

Old school PCB for sure :D

Can you have a look to the read data signal with an oscilloscope ?

z23
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Joined: Fri Aug 23, 2019 6:03 am

Re: Emulating an Exatron stringy floppy with a gotek?

Post by z23 »

Jeff wrote:
Mon Sep 23, 2019 11:54 am
Old school PCB for sure :D

Can you have a look to the read data signal with an oscilloscope ?
Hi Jeff, it just occurred to me that I probably need a cassette to put in the drive to observe anything happening and I don't currently have one. I've ordered one from ebay but it won't be here until October. Also it is missing the belt but could probably just do the rubber band trick like on a QuickDisk drive. I can hear the motor spin up so that's a good sign. I also found a broken MPSU51 transistor which will need to be replaced...
i guess it'll be a few weeks until I can get back to this :/

Jeff
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Re: Emulating an Exatron stringy floppy with a gotek?

Post by Jeff »

ok so maybe the write data line then ?

z23
Posts: 26
Joined: Fri Aug 23, 2019 6:03 am

Re: Emulating an Exatron stringy floppy with a gotek?

Post by z23 »

Well.. I just fixed my prophet 10 power supply and the Exatron drive... received the new tape, went to see what was happening on the oscilloscope and then the tape got eaten. I saw what looked like square waves while it was saving, and without a tape I get some weird shape while reading. I honestly don’t know what I’m looking for, what settings on the scope I should be set to ( had it at 20mv/div and h was set to .1ms). Does this waveform look like what we should see?
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