Floppy Drive Emulators on PC-98 - Flashing HxC Firmware to a Gotek FDD Emulator

[SkyeWelse]

Hi Everyone,

I just put up this video tutorial in case anyone is interested in learning more about replacing your mechanical FDDs with a Floppy Disk Emulator and how to prepare the cheaper Gotek FDD Emulators with HxC firmware which can read converted .D88 formats.

Hope it can be of some help!

https://www.youtube.com/watch?v=Q2qVgBJUI5U&feature=youtu.be

-Thomas

[skpstmgs]

Thanks for the helpful video, SkyeWelse. It actually made me try out converting my Gotek USB Floppy emulator to HxC firmware. I've only tested the Gotek on my regular IBM DOS machine after converting and it seems to work, but I'll try it with my PC9821 soon. Unfortunately, it looks like my model (PC9821 XA7) only supports one 3 1/2 floppy drive. Is there any hope of hacking in another one do you think? I'm not sure if you can use those same cables that you would on an old IBM DOS machine that have 2 floppy connectors in one cable, with some of the wires crossed over at the end. How do the cables in yours work, as an example?

[SkyeWelse]

Hi skpstmgs! Glad the video was of help to you. So the Gotek running HxC cannot be used to operate 2 FDDs, but a real HxC would be able to as long as you had the cables from a second floppy connector cable attached to some of the pins. I've not setup a real HxC to emulate two drives, but maybe one of these days I'll figure that part out.

However you can use two Gotek FDD emulators flashed with HxC firmware and connect them as long as you have some special cables. Sometimes these cables are sold as spares on Yahoo Auctions or you could probably make your own. I took some pictures to help show you what these cables look like and how they connect on the motherboard. The FDD cable connects to the backside of the C-BUS module on my Ce2, and the bottom FDD drive has the last two wires twisted / alternating.

http://retro-type.com/PC98/dual-fdd-cables-01.jpg
http://retro-type.com/PC98/dual-fdd-cables-02.jpg
http://retro-type.com/PC98/dual-fdd-cables-03.jpg
http://retro-type.com/PC98/dual-fdd-cables-04.jpg
http://retro-type.com/PC98/dual-fdd-cables-05.jpg
http://retro-type.com/PC98/dual-fdd-cables-06.jpg

Hope this helps!

-Thomas

[skpstmgs]

Thanks for the info and pics! I was looking at Yahoo Auctions Japan and it looks like there are a few different types of floppy cables currently on sale and sold in the past, but they all look different, so not sure if some models require different types of cables or what. Do you have any experience using the external floppy drives? Maybe I could find one of those and replace the innards with a Gotek. I'm not sure what kind of cable those normally require though.

[SkyeWelse]

Sure no problem! I have actually hooked up a separate set of PC-98 5.25 inch drives before. It's actually this monstrosity here:

http://retro-type.com/PC98/ExternalDualFDD/5inchquarter_doublediskdrive.jpg
http://retro-type.com/PC98/ExternalDualFDD/External-Floppy-Drive-Inside-Components-01.jpg

Originally it's a pair of FDD drives that connect to a small PCB that is hooked to a Centronix 50-pin SCSI? cable and you would normally hook that up to a C-BUS card like this one:

http://retro-type.com/PC98/FDD-1M1Z.jpg

When I got it, it didn't power on and it had some battery leakage unfortunately. So after replacing the caps in the PSU I was at least able to use it to power the two drives, and both of the FDD drives used a FDD connector like this:

http://retro-type.com/PC98/ExternalDualFDD/External-Floppy-Drive-Inside-Components-06.jpg

Which connected to the 34-pin FDD connector on the C-Bus module that is inside the Ce2, where the 3.5 inch FDD drives would normally plug into. I was able to read and write floppies using that method instead of hooking it up to the Centronix port on the back of the C-Bus card I have.

Maybe it might help if you took some photos of your current setup and how your current drive is hooked up? Do you have a 26 pin drive or a 34 pin drive? There are adapters you can make / buy off of Yahoo Japan Auction for a 26 pin to 34 pin conversion.

-Thomas

[skpstmgs]

Here's what it looks like in general. The cover in front of the floppy comes off so I've actually removed that and put the Gotek in the bottom 3 1/2" slot for now.
The WD HDD isn't actually hooked up; I use a CF adapter in the back.
http://i.imgur.com/lrmXUTe.jpg

The 3 1/2" FDD uses a 34pin straight cable with only one connector at the end. My main issue now is getting a floppy cable with 2 connectors on it for hooking up 2 Goteks.
http://i.imgur.com/1Oh7Hjm.jpg

One port on the motherboard for the 34pin floppy. one IDE for the HDDs, and another IDE for the CD-ROM drive.
http://i.imgur.com/ndwPpem.jpg

I was mostly interested in the external drives before because I didn't think there was a way to accommodate 2 Goteks internally, but with the floppy section of the front cover being removable, it actually makes it really easy. I'm still interested in knowing how exactly the external drives work though. When you plug in one of those expansion boards into the C-Bus, do you get 2 additional floppy drives, or does it piggyback somehow off the motherboard?

[SkyeWelse]

Hi skpstmgs,

So from your photos it does seem like you are all covered as far as PSU and extra mini-molex connector is concerned to power the second Gotek. All you need now is one of the cables that I showed a picture of above with the bottom cable having two pins reversed for the second drive. You could probably make your own from an existing floppy cable or sometimes they sell them as parts on Yahoo Auctions like this one: http://page3.auctions.yahoo.co.jp/jp/auction/c581696764

That external 5"inch dual drive would normally get hooked up to a C-Bus card that supports 1.2 mb external disk drives which I have, but I've never been able to get my Ce2 to see it when connected to the C-Bus card by way of the 50 pin Centronics cable. That C-Bus card hooks up in a special way to the Ce2 motherboard's FDD connector. 

So instead, I use the PSU that is affixed to the external drive to power the drives but then I hook a floppy cable that has 34 pins on one side and the double-sided teeth connector that slip around the flat gold connectors on each of the 5.25 inch drives and use that cable to hook it straight to the Ce2 motherboard's FDD connector bypassing the C-Bus card entirely.

EDIT: This is what it looks like for a better picture of what I'm referring to with this setup:
http://retro-type.com/PC98/external-fdd-hookup-to-pc-9821ce2.jpg

Obviously, it's not a pretty setup, but I use it only when I need to dump 5.25 disks or write to 5.25 disks.

-Thomas