OSI 8" Drive working with Gotek emulator

[billdrom]

I have been working on getting some eight inch drives working with the Gotek emulator and have had some success. I won't go into all the trials and tribulations encountered in this process but instead just describe what worked for me.

First I am using flashfloppy version 2.14 on the Gotek which I modified by adding an oled display.
It gets very confusing when trying to remember what disk image is stored in what filename.
The display which I got from amazon (DSD Tech .91 inch, package of two) has the 4 pin header already installed.
I give the files descriptive names for easy identification. If the name is long, the display will scroll.

I only use one jumper on the Gotek. Either ds-0 or ds-1 depending on whether I want drive A or drive B.

I am using the Klyball D-13 version 1 data separator board.
There is no need to bypass the separator even if your eight inch drive has one built in.
I just use the Klyball separator for both the Shugart and the Gotek.
I first set the pulse width to 2.5 microseconds but later to 2.7, both worked and I don't know which is better.

You need a 50 pin ribbon cable with at least one eight inch floppy connector for the floppy drive and at least two 50 pin plug connectors. One for the D-13 separator and one for the adapter used with the Gotek cable. I made a cable by installing a 50 pin floppy connector on a cable I got from amazon that already had two plugs on it.
You will need a 34 pin cable to connect the adapter to the Gotek.
You will need power for the gotek. I am using an old PS from an external drive reader.

I am using a 470 card configured for eight inch single sided floppys.

You need to build or get a 50 pin to 34 pin drive adapter for use with an eight inch controller.
There is one on github that would work, part number FD50to34 but I just used the schematic on the webpage as a guide to make my own. I skipped all the motor control and drive select parts.
I used a radio shack P/N 2760150 proto-board which is $3.00 on Radio Shacks website..
I actually started to make my own data separator which didn't work, so I took out the chips and used it as an adapter. You just need one 50 pin socket and one 34 pin socket and about 15 or so jumper wires.

gotek-adapter.jpg (462.19 KiB) Viewed 7898 times

I used Mark S. latest version of OSIHFE program to convert Eight inch .65d files to .hfe files and loaded them to a memory stick from my PC. Don't forget to make some blank files and put them on the stick also. Put the stick in the Gotek, move jumper to 0 and reboot the OSI computer.
Use the buttons on the Gotek to select a file. Type D and voila! The system is booted.
If you want you can leave the floppy drive as 0 and set the Gotek to drive one.
Boot from a floppy and copy from drive A to drive B (remember to select a blank file as the destination).
You can then boot from the file you just wrote.

Also you can copy from drive B (Gotek)to drive A (Floppy) and generate a bootable floppy for later use.

Bill

[CrawfordG]

Bill,

Great work! As you know, I also want to get my 8” drives working with the D-13 and Gotek/flashfloppy.

I will be replicating your work very soon. I could not view the image you posted, though..

-Crawford

[billdrom]

I made an improved 8" to 5 1/4" floppy adapter for the gotek.
I used a Busboard SB400 solderable breadboard from Jameco.

This board has the advantage that there are two extra buses on it that allow you to install the connector headers such that all the odd number pins are connected together and each of the even numbered pins has its own five hole pad to solder the jumpers.
It makes it very easy to build. Every pin and every jumper connection has a solder pad.
Make sure the odd pins are the ones connected together.
The row under the notch has the odd number pins.
There are only Thirteen wires to install.
First connect the ground pins on each connector together with a jumper.
Then install the rest of the jumpers.
50 Pin Conn 34 Pin Conn
46------------------------30
44------------------------28
42------------------------26
40------------------------24
38------------------------22
36------------------------20
34------------------------18
28------------------------12
26------------------------10
22------------------------34
20-------------------------8
14------------------------32

adapter-front.jpg (609.95 KiB) Viewed 7801 times

adapter-back.jpg (700.62 KiB) Viewed 7801 times

[CrawfordG]

Bill,

I’m just curious, since you are using a D-13. Did you try using two cables from the D-13? What I mean is, plug the 8” drive cable into the D-13 50 pin connector, and a regular 34 pin cable into the D-13 34 pin connector for the Gotek.

I was just wondering if this would work out electrically.

-Crawford

[billdrom]

That is a great idea.

I just tried it and it works .
Was able to run the OSI disktest program from http://www.pdp8online.com/osi/osi-floppy-test.shtml and it passed perfectly.
Was able to copy a file from the gotek to an eight inch floppy and then boot from the floppy.

So I guess there is no need for any other adapter unless you want to keep the two drives together.
You don't even need any special connectors on your 50 pin 8" drive cable.
I only used a twelve inch long 34 pin cable for testing. I don't have any really long 34 pin cables to test it with.

[lowrybt1]

Bill,

Can I verify one thing? Is it possible to use the Klyball D-13 to connect both a Gotek (no data separator) and 8" Shugart with data separator by default? In otherwords, to use the D-13 with one device with and one without data separator?

Thanks, Tom

[billdrom]

Yes, I only have the one separator on the D-13.
I was able to copy from the 8" to the gotek.
You have to have a blank or other file on the gotek first to copy.


Bill