Yamaha Floppy Drive Emulator?

Page 1/3
| 2 | 3

By Cosmolac

Rookie (22)

Cosmolac's picture

15-02-2019, 07:24

So I have a yamaha fd03 cartridge laying around but not the drive that its used with. I was wondering would it be possible to attach it to a typical floppy drive emulator and use it to load programs to my computer? Im mostly concerned with msx software right now as I havent converted my cx5mII to msx2 yet so if its not compatible with later software its not the end of the world.

Login or register to post comments

By rderooy

Hero (580)

rderooy's picture

15-02-2019, 07:58

Yes I think it should be possible to connect something like a Gotek to it. You will need to check out the service manual, and find a way to map the connectors to that of the floppy emulator.

https://www.msx.org/wiki/Yamaha_FD-03

One issue though, is that the FD-03 is only a single-sided (360kB) controller, so you may need to find a firmware for your floppy emulator that supports that. I don't know if there is a replacement ROM for the controller to support 2DD media.

Regarding MSX2, there is no issue. If it works on MSX1 it should also on MSX2.

By Cosmolac

Rookie (22)

Cosmolac's picture

15-02-2019, 08:18

Thank you so much! Once I look at the pinout I ll see about making a cable and trying it out. I completely missed that it was 360kb I ll look into that more too. On a related note is there any means for easily converting msx roms to floppy disk images? and also cas files?

By rderooy

Hero (580)

rderooy's picture

15-02-2019, 08:48

Have a look at sofarun, or just search the site as it has been asked before.

By Alexey

Guardian (2349)

Alexey's picture

15-02-2019, 10:33

Not 100% sure, but the disk ROM from FD-051 could solve the one sided drive problem. The pinout of the cable should be identical.

By rderooy

Hero (580)

rderooy's picture

15-02-2019, 11:32

Also, if your able to. It would be nice if your able to dump the ROM of the FD-03, as it has not been archived. This way support can be added to openMSX.

Alexey: I don't understand your comment. The FD-051 has a completely different cable compared to the FD-03. The FD-03 uses a type of DIN connector, while the FD-051 uses a type of IDC connector. Also, just like the FD-03 we don't have a ROM dump of the FD-051 either to my understanding.

By Alexey

Guardian (2349)

Alexey's picture

15-02-2019, 12:31

Oops, my bad! Please ignore what I said. Assumptions are never good.

The dump of the FD-051 bios can be found here:

http://podrezov.com/temp/FD-051.zip

Manual:

http://podrezov.com/temp/FD-051_Man.pdf

By Cosmolac

Rookie (22)

Cosmolac's picture

16-02-2019, 09:16

Hm I dont currently have the means to dump the rom but Ive been meaning to grab an eprom programmer anyway so i might as well do it sooner rather than later and then upload the fd03 rom here.

Also could it be possible that modifying the fd03 itself could fix the compatibility issue with floppy emulators? Im assuming that may end up being way too involved...

By Manuel

Ascended (15691)

Manuel's picture

16-02-2019, 23:18

Alexey: I created an openMSX config file for this drive with that ROM. It seems to work mostly, but when I try to format a disk, it gives a "Disk error" after the formatting seems to be completed... Do you know in which way the memory mapped registers are mapped on this drive? Is it the same as the Philips drives?

By Alexey

Guardian (2349)

Alexey's picture

17-02-2019, 14:17

According to our engineer it should keep its registers in the end of its ROM (7FF0). It doesn't verify the result of track writing operations and writes FAT and directories without even checking the availability of the sectors. The below data may not be 100% accurate, but I have no way to verify, sorry.

FDC_C 7FF0 FDC command (wr)
FDC_S 7FF0 FDC status (rd)
FDC_T 7FF1 FDC track register
FDC_SE 7FF2 FDC sector register
FDC_D 7FF3 FDC data register

MOTOR 7FF4 - bit(0) = 1 - motor on / 0 - motor off
DRIVE 7FF5 - bit(0) = 1 - drive 1 / 0 - drive 0 (DS1/DS0)
DSKCST 7FF6 - bit(0) = 1 - disk no change / 0 - disk was change
FDC_R 7FF7 - bit(7) = -DRQ
xxxxxxxxxx - bit(6) = -IRQ

By Manuel

Ascended (15691)

Manuel's picture

17-02-2019, 20:36

Alexey: where did you get this info from? From the schematic? It seems to be a unique way of mapping the FDC to the memory addresses...

Page 1/3
| 2 | 3