The Perfect Modern HDD is SCSI2SD

FM Towns as we know is quite old. If you are lucky enough to revive a PC that has a hard drive its generally about to die and has low partition size. Recently in my HR100 I revived the 100MB hard drive sounded like fighter jet and was dead. This guide is written with the assumption that you have changed the CMOS battery in your computer and you want to use a SCSI2SD for TownsOS installation.

First of all why do you need hard drive?

For one if you want to explore the obscure computer software that required an installation it’s necessary for some. There is a small amount of software requiring hard drive installation specifically the later DOS ports generally requires some. Wing Commander, Wing Commander Armada and Return to Zork come to mind. That isn’t to say there are more…because there are more :p However understand not a LOT of software requires a hard drive. Perhaps 5-10% of the software library (notice how I didn’t say game library) requires it.

To use a SCSI2SD you will need to buy one of course and I’ve been using the 5.2 model which I got from inertial computing SCSI2SD ( inside all my FM Towns and X68000 computers. Grab a 16GB card as well. I usually use SanDisk cards. You’ll also need a SCSI50 to IDC50 cable. You can get it here…and no it isn’t affiliate link.

12″ CN50 50-Pin Male to IDC50 50-Pin Female Ribbon Cable, CablesOnline FS-1012 | eBay

If your desktop towns comes with the hard drive tray and cables I highly recommend you use those. I would also recommend using tape on the bottom of the entire SCSI2SD or metal hard drive tray so it won’t short. This is if you choose to install it internally. Tower models I would strongly recommend external install since it’s a nightmare to access the hidden hard drive bay area.

Next is a correct micro-USB cable. It MUST have the notches on top.

The photo above is the correct type to have as it can transmit data and has the notches to indicate that. The photo BELOW this one (white cable) is a power cable and doesn’t have proper termination length to transmit data. You can’t use this.

Again the photo above that cable won’t work to transmit information. You will also need the firmware app which is located here Index of /files/scsi2sd/latest (

So start the file and after plugging in your SCSI2SD it will detect the device in the app. If it doesn’t say what the red box says, you’re using a bad cable.

Here is the recommended settings which are ironically kind of the default settings. Note that we have set SCSI device 0. If you are using a UX/UG/UR or an all-in-one FM Towns you must set the SCSI ID as 1. These models don’t have SCSI ID 0 available in the boot ROM.

So now configure the device by clicking File and then Save to Device

The LED will flash a lot which is totally normal. Once it’s complete disconnect it. You’re done! So when it’s connected to a Towns it will look something like this externally.

We don’t need a 5V or GND connection. It receives enough power from the termination resistors to operate. So you could place it on top of your desktop also if you don’t have that metal hard drive tray floating around. Remember to tape off the SCSI2SD if you do that as most computer cases are made of metal! The cable in the photo above with CX20 is about 18 inches long. It isn’t long enough to sit the hard drive on the top of the tower so if you want a cable that can do that you may need to find a slightly longer cable. Just letting you know.

So perhaps the next step is to insert that unformatted 16GB Sandisk card into the SCSI2SD and install TownsOS! Remember to replace the CMOS battery in your Wizard ODE / Battery Pack / Motherboard before installing anything to your hard drive. Failure to do this will result in your SRAM not saving hard drive settings meaning you must manually enter them each time.

Sean did a nice article here on how to install TownsOS. Thanks Sean! Subscribe to his page also it’s very excellent. Towns OS HDD Installation – Japanese Vintage Computer Collection (

One thing to mention when installing TownsOS. These lasers are literally as old as I am but have been quite battered. Sometimes during TownsOS installation you will get a message saying the laser cannot read the CD. Click the left option in the dialogue box to resume reading the CD and continue hard drive installation.

There is one last thing to mention. It is possible to pre-configure hard drive settings and partition settings inside TownsOS if you have severe trouble installing to the hard drive with your disc drive. Then you can use WIN32DISKIMAGER program to flash a hard drive image to an SD card. I cannot find the hard drive image I’ve used in the past. Maybe a reader can comment below? I’ve done this before with Towns Fresh when it was having severe trouble reading during installation. Anyway I like the install method as it also let’s you see how your laser is faring and holding up.

One thought on “The Perfect Modern HDD is SCSI2SD

  1. Thanks for posting this. I’ve been eyeing a SD2SCSI for a while but several things that were unclear you’ve clarified in this article. You mentioned a hard drive mount – can you clarify what specific part you mean (pics would be nice) – is that for mounting the SD2SCSI internally? Also you mentioned the Wizard – I didn’t think those were in the wild yet, are you beta testing one for Deunan or just mentioning it because when they are released they’ll house the CMOS battery?


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