No idea where to start | MSX Resource Center (Página 2/3)

Por Manuel

Ascended (17511)

01-07-2016, 21:41

Is the external drive configured as B-drive? (DS jumper)

Por Stefan Schnitzler

Supporter (6)

01-07-2016, 22:56

well it doesn´t have any jumper pins

Por Wild_Penguin

Hero (623)

01-07-2016, 23:57

Stefan Schnitzler wrote:

well it doesn´t have any jumper pins

I think herein lies the problem: MSX expect drives that are selectable with jumpers, where as PCs made the selection by having the corresponding pins swapped in the cable; i.e. on a PC floppy drive cable, if you had the drive after the twist, it would be master, and if before, slave. Otherwise the drives are identical. http://www.nullmodem.com/Floppy.htm

Some PC drives still have the jumpers, some have a spot to solder some. It is possible to make all drives work with some soldering, or making a custom cable. But make sure you got the right details if you attempt this!

This information is from the top of my head, so I could misremember something (someone might chime in if that is the case). Also, I'd make sure the pinout at the back is actuially standard. Hans Ottens page has information about MSX floppy drive interface pinouts.

EDIT: I see from the picture that your cable has the twist ... try to find a cable that doesn't have it (or has two connectors so you can choose which one to use).

EDIT2: Maybe you already noticed this:

Hans Ottens page wrote:

For VG8235

This MSX computer has a diskrom only suited for a single sided drive. To makeuse of a doublesided drive, including the PC type, you need to replace the diskrom with the rom from a VG8245, see the manual how and where.
Also you need to add the side selection signal, not present at the internal drive A but available at the connector for the external drive B. Connect pin 32 of drive A to pin 32 of the external connector for drive B. Again, see the VG8235 service manual!

Por Wild_Penguin

Hero (623)

01-07-2016, 23:47

Stefan Schnitzler wrote:

okay the first think i tried was to format a 720kb dd to a 360kb disk on the msx. Unsurprisingly this didn´t work.

What was the error message / problem? I think it should actually "just work", unless the drive is broken (even 1440kb floppies should work, just rememeber to cover the hole when you put the disk in a HD floppy drive on your PC...).

Por Manuel

Ascended (17511)

02-07-2016, 00:04

Wild_Penguin: I didn't check, but I think the jumper does exactly what the partially twisted flat cable does. So you don't *need* a drive with jumpers, just as long as you have some way to configure it as drive B.

Por Wild_Penguin

Hero (623)

02-07-2016, 00:14

Manuel wrote:

Wild_Penguin: I didn't check, but I think the jumper does exactly what the partially twisted flat cable does. So you don't *need* a drive with jumpers, just as long as you have some way to configure it as drive B.

I believe you are correct. The page I linked above has it explained quite well, I think... in this case I believe a cable without a twist is needed (Then a jumperless floppy drive should be B.

Por tvalenca

Paladin (747)

02-07-2016, 00:24

Ok, but there's a catch:

IBM didn't followed Shuggart standard, so where IBM standard has two Motor enable signals and two Drive Select signals, Shuggart has one Motor enable and FOUR Drive select signals. (Yes, MSX could have supported 4 drives per FDCs, but MSX FDC and DiskROMs didn't implemented that) That's why you have to undo the cable twist on a IBM floppy drive cable when using a PC disk drive on MSX.

Por Stefan Schnitzler

Supporter (6)

02-07-2016, 11:47

Wild_Penguin wrote:

I see from the picture that your cable has the twist

Yes thats right

Wild_Penguin wrote:

What was the error message / problem? I think it should actually "just work", unless the drive is broken (even 1440kb floppies should work

There isn´t any error message. Apart from some Floppy noises nothing happens. I also tried to format the DD disk to 360kb on a XP PC and an old DOS Notebook using command line and third party tools. Booth times it says something about the floppy drive not beeing compatible. I don´t have any HD disk´s right now but i´m gonna give them a try if i find some.

tvalenca wrote:

That's why you have to undo the cable twist on a IBM floppy drive cable when using a PC disk drive on MSX

okay that´s very interesting. I thought it was the other way around. I´m gonna search for a normal cable in my PC stuff and give it a try.

In the meantime here´s a short video of what happens when i try to format a DD in the MSX (it´s not in the video but i waited about 15 minutes or so and nothing changed)

https://youtu.be/Ik8_8h51FHQ

Por Wild_Penguin

Hero (623)

02-07-2016, 12:55

Stefan Schnitzler wrote:

In the meantime here´s a short video of what happens when i try to format a DD in the MSX (it´s not in the video but i waited about 15 minutes or so and nothing changed)

https://youtu.be/Ik8_8h51FHQ

WHOAH, that's a dusty MSX! :D

In any case it seems quite obvious the floppy drive is broken? I don't know about the VG-8235 floppy drive, but if it has a belt, it is probable it has disintegrated over time (unless someone has replaced it).

Also, I gather from the Hans Ottens site (which I quoted above), that unless someone has replaced the original disk ROM, you can not use a DS,DD (=720kb) drive (or, it might work just as a SS,DD (=360kb) but I really don't know).

Por Stefan Schnitzler

Supporter (6)

02-07-2016, 15:54

Wild_Penguin wrote:

In any case it seems quite obvious the floppy drive is broken? I don't know about the VG-8235 floppy drive, but if it has a belt, it is probable it has disintegrated over time (unless someone has replaced it).

You could be quite right about that. It doesn´t seem to spin the disk at all

https://www.youtube.com/watch?v=gb8DzgkPk1g