China DOS Union

You can use HDCOPY to format a floppy disk to 1.72M, then set the floppy drive to 2.88 in CMOS, and then you can boot with this floppy disk.

[ Last edited by 3dfx on 2006-6-17 at 13:03 ]

Hehe, it's no use. I've already tested the floppy disk capacity expansion of HD-COPY. The maximum stably accessible formatted capacity is only 1,501,184 bytes, at most 82 tracks and 18 sectors per track. If you exceed these parameters, you can't access stably, although HD-COPY can stably format the maximum parameter capacity. Even if you set the floppy drive to 2.88M in CMOS, it's still impossible to access normally by residenting the dedicated super-capacity floppy disk reading and writing program fdread.exe or fdread2.com of HD-COPY in memory.

I have already experimented with this, and it is definitely possible. The maximum is 1.72M, and there is no need to have any dedicated read-write software resident in memory.

Mini-Windows 3.2 Chinese version uses a 1.68MB floppy disk image...

Yes, I've tried. Both the 1.72MB and 1.68MB ones can work normally under DOS, and there's no need to set the floppy drive in CMOS to 2.88MB. It's just that the 1.72MB one doesn't work under 2k/XP.

I don't know what kind of normal use you are referring to. If it's 1.68M, I remember it seems it can start up and can access the first few sectors normally, but it doesn't work for the last few sectors; the 1.72M one can't even do normal dir, copy files, etc. I tested it like this. It's not that being able to copy files means it's okay, but to see if it can pass the full-disk scan of scandisk. Also, this is related to the floppy drive itself. Some floppy drives don't support non-standard track and sector numbers, that is, their "overclocking" performance is relatively poor. In general, after my tests, the 82-track one has the best versatility. As for increasing the number of sectors per track, the versatility is even worse. Some floppy drives don't even let you increase one sector, and they can't even read it out.

I used to often use HD-COPY to format floppy disks to 1.72M, and didn't find any problems

I used to often make a 1.72M system disk frequently. You say can it be used...

Hey, didn't I already say that? This depends on how your floppy drive is. Just because your floppy drive works doesn't mean other floppy drives will. When I make a boot disk, I can't just think about it working only on my own machine. I also need to consider generality. If one doesn't work, it means a certain format isn't universally applicable. Do I not want to make full use of the capacity?

By the way, I found that the expandability of 5-inch disks is actually better than that of 3-inch disks. I formatted it to the maximum capacity, and it can still be read and written normally without any super-capacity reading and writing programs resident.

When I used DOS 7.1 and Win98 before, I also used QEMM386 8.0 and 4DOS 5.xx. At that time, it was at most a little more than 610K. Under DOS 6.22, it could reach 634K. It's really powerful. In my DOS 7.1, the system is more than 10K, and it can't be less anyway...

I just remember that when using DOS 6.2 back then, I once reached up to 627K

[ Last edited by barney on 2006-7-20 at 15:55 ]

It's only 620KB, that's too exaggerated.