Replace a MSX turboR Diskdrive with a PC Drive.

Instruction designed and written by Erik Luppes (luppie), original here, reproduction kindly permitted by Erik.

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

Panasonic FS-A1FX
Panasonic FS-A1WX
Panasonic FS-A1WSX
Panasonic FS-A1ST
Panasonic FS-A1GT

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. (DiskChange via a switch to ground, extra TTL logic for the RDY signal)

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 desolder the 24pin ZIF socket from the defect diskdrive. I’ve put this ZIF socket on a small prototype PCB together with a 17-pin header (even pins 2 -> 34) The odd pins are all connected to ground so not used.

On the small PCB the following connections are made:

Signal	24 pin ZIF	34 pin FDD
+5V	1	Power Connector
RDY	6	34
GND	7	Power Connector
Side Select	9	32
Read Data	11	30
Write Protect	12	28
Track 00	13	26
Write Gate	14	24
Write Data	16	22
Step	18	20
Direction Select	19	18
Motor On	20	16
Drive Select 0	22	10
Index	23	08
Disk Change	24	02

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)
. Solder a wire between DC and OPB (to put DC on pin 2)

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.

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