Hi!

I recently bought a Philips VG 8235 with a PC diskdrive. It seems that I am able to use HD disks on the MSX computer (holes not covered). Is that supposed to work?

maybe its a 720kb drive
or maybe the diskdrive dont see the diffirence between HD and DD

For sure it will not format the disk with 1.44mb

Back in the old days, Henrik Gilvad played with the thinking to make a 1.44 on his MSX.

But he said the diskcontroller can handle it, and also maybe to few memory or cpu speed to handle it.

I dont know. The diskrom have to be modified to read/write 1.44 disks. Its not possible just to change the drive

-CB-

You can only format them as 720kB DD disks.
If not, you have something special and unique

Covering the hole is needed by the PC to read HD flopies formated in 720K disk, not by the msx itself, the HD drive on the pc is who need it.


The only way to use 1.4 flopies on MSX is to use an LS120 unit with an IDE controller (or SCSI if exist)

The FDCs of the MSX are not clocked in the way, that would make reading HD discs possible.
Maybe you can modify your disc rom + writing fast enough routines, so that the Z80 can read the double speeded data stream of a HD disc, but your FDC would still fail.

Thanks for the quick replys!

The HD disks could only be read after I formatted them on the MSX. However, I thought that I couldn´t even format HD disks on the MSX-computer without covering the holes.

It depends on the disk drive.

if the diskdrive in your msx is a true dd (720kb) you dont need to cover hd hole on the disk.

or if its a 1,44 drive maybe its modified so it dont detect the hole maybe the switch are removed or something

anyway if you dont cover the hd hole you cant read the disk in a pc (with a 1,44drive)

-claus-