Replace a Panasonic FS-A1F Diskdrive with a PC Drive.

This instruction shows how to connect a Samsung SFD-321B FDD to a :

Panasonic FS-A1F

On the Internet I found a couple of instructions on howto connect a PC drive to a Panasonic MSX. In my opinion these instructions are to complex and/or not 100% compatible with the original diskdrive.

This instruction works with older revisions of the Samsung SFD-321B.
Please make sure that the Samsung SFD-321B you use has a HD sensor (the newest revision of this drive does not have this sensor, causing no support for formatting 720kb DD disks)

To minimize the damage to the mainbord I chose to make a small convertor on a small prototype PCB.

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On the small PCB the following connections are made:

Signal 26 pin MSX 34 pin FDD
GND 01 Power Connector
RDY 02 34
+5V 03 Power Connector
Index 04 08
Drive Select 0 06 10
Motor ON 08 16
Side Select 10 32
Direction Select 14 18
Step 16 20
Write Data 18 22
Write Gate 20 24
Track 00 22 26
Write Protect 24 28
Read Data 26 30

To make the Samsung SFD-321B 100% compatibel the following modifications need te be maded.

Replace jumper DS1 to DS0 (To make it the A drive)
Replace jumper DC to RDY (To put the RDY signal on pin 34)
Put a jumper on OPA (this adds 720kb support)

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Since the diskdrive has a HD Disk sensor, you need to put a piece of tape on the HD hole. To overcome this, it is possible to remove the HD sensor.

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Now you’ve got a 100% compatible diskdrive, without modifications to your mainboard.

7 replies on “Replace a Panasonic FS-A1F Diskdrive with a PC Drive.”


I’ve been having issues following this tutorial. I’ve connected everything as you said to, and the LED on the SFD-321B lights up. However, it stays lit constantly, and when I try to format a disk or list the files, it spits out “DISK OFFLINE.” Any advice?


Hi Erik,
Thanks for getting in touch so quickly. Sorry for the slow response, but I’ve been rather busy lately.

Anyway, I’ve checked the connections multiple times, and am about to go check them again. I was wondering where you found the pinout schematics for the 26pin MSX connector?


I found the FS-A1WX datasheet on
Since the FX is almost the same as the WX and uses the same diskcontroller, it will also work on the FX – WX – WSX – ST & GT.

Thank you very much, I’ve found the datasheet. It’ll take a while, but I’m double-checking my connections and cross examining them with the corresponding pins on the TC8566F chip. It’ll take a while, but this way I’ll know where I’ve made mistakes.

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