Question for Wengier about NEC-format floppy disk images - China DOS Union Forum

The NEC disk format is a disk format widely used on NEC computers in Japan. Its logical disk layout is exactly the same as the DOS logical disk layout. The only differences from the standard DOS disk format are the number of tracks, the number of sectors per track, and the number of bytes per sector. Taking a 5.25-inch double-sided high-density floppy disk as an example, the standard DOS disk format is 80 tracks per side, 15 sectors per track, 512 bytes per sector, with a formatted capacity of 1.2MB, while the NEC disk format is 77 tracks per side, 8 sectors per track, l024 bytes per sector, with a formatted capacity of 1.232MB.

This NEC-format floppy disk is widely used in numerically controlled machine tools made in Japan, generally using a twisted-cable floppy drive. With a USB floppy drive, whole-disk copying is possible, and it can also be read and written.

Because floppies are inconvenient to preserve, I want to save them as IMG images, and then write them back to floppy disks when needed. I'd like to ask Wengier whether there is any software that can read and write NEC-format images.

But I have searched the entire web. For example, image software such as Floppy Image Master, rawwritewin, and FLOPPY IMGAGErawwritewin does not support this format. The results are as follows:
Floppy Image Master 2.4
http://www.onlinedown.net/soft/47289.htm
It does not recognize this format, so it cannot generate an IMG image, and of course it also cannot write it back to floppy;
This software is very good for standard floppies. Too bad the author no longer updates it. It would be great if it were compatible with this format.

rawwritewin 0.7
It can read out an IMG file, but after writing it back to a floppy, the floppy cannot be opened and prompts for formatting.

FLOPPY IMGAGE 2.4.0
http://download.pchome.net/system/disk/detail-8678-1.html
It can read it out and save it in IMG format, but it shows the size as 616k, even for a 1.232M floppy. Without formatting the target disk, it can write it back to the floppy. I first used the format command to format the floppy as 1.232M, then used this software to write it back without formatting. It could be opened and the files could be seen, but it could not boot.

Under XP, if you right-click the floppy drive and click "Copy Disk", it can copy it, and after copying the two disks are exactly the same and can boot.

So, what software can be used to save an IMG and write it back to a floppy?
Thanks!jinkun23@sohu.com

[ Last edited by zk9523 on 2010-5-16 at 16:36 ]

Haven't you tried HD-Copy?

Right, I also recommend using hd-copy.

Also, one-to-one copying software like dd for win should not have any problem either.

Originally posted by wl00560 at 2010-5-15 07:53 PM:
没有试过HD-Copy？

HD-copy only supports 80-84 tracks, while NEC format is 77 tracks, so it is not supported and directly shows a disk error.

It probably requires NEC-specific floppy disks and floppy drives.
Ordinary floppy drives and floppy disks won't work.

@lianjiang

Didn't the OP already say in the first post that Windows' disk copy function works?

There is a tool here that supports the NEC format. You can give it a try:

http://ftp.vector.co.jp/pack/dos/util/disk/fddiag03.lzh

-------------------------------------------------------------------
FDDIAG A floppy disk maintenance program

This program is for the NEC PC-9801 series, and performs sector-level
read/write operations on floppy disks, as well as physical formatting of
media on a track-by-track basis. When reading from or writing to files,
it can also simultaneously convert between a block-structured fixed-length
format and a text format editable with MS-DOS editors, and also perform
code conversion to and from EBCDIC.

Originally posted by lianjiang2004 at 2010-5-17 10:19 AM:
Here's a tool that supports NEC format. You can give it a try:

http://ftp.vector.co.jp/pack/dos/util/disk/fddiag03.lzh

------------------------------------------------------------ ...

Thank you!
I downloaded it, but unfortunately I don't understand Japanese. I looked at it for a long time and still couldn't make sense of it. Could you please provide specific usage instructions? It would be best if you could give a simple explanation specifically for NEC format. Thanks again!

Floor1　zk9523	Posted 2010-05-15 15:55
新手上路　Posts 4　Credits 10
The NEC disk format is a disk format widely used on NEC computers in Japan. Its logical disk layout is exactly the same as the DOS logical disk layout. The only differences from the standard DOS disk format are the number of tracks, the number of sectors per track, and the number of bytes per sector. Taking a 5.25-inch double-sided high-density floppy disk as an example, the standard DOS disk format is 80 tracks per side, 15 sectors per track, 512 bytes per sector, with a formatted capacity of 1.2MB, while the NEC disk format is 77 tracks per side, 8 sectors per track, l024 bytes per sector, with a formatted capacity of 1.232MB. This NEC-format floppy disk is widely used in numerically controlled machine tools made in Japan, generally using a twisted-cable floppy drive. With a USB floppy drive, whole-disk copying is possible, and it can also be read and written. Because floppies are inconvenient to preserve, I want to save them as IMG images, and then write them back to floppy disks when needed. I'd like to ask Wengier whether there is any software that can read and write NEC-format images. But I have searched the entire web. For example, image software such as Floppy Image Master, rawwritewin, and FLOPPY IMGAGErawwritewin does not support this format. The results are as follows: Floppy Image Master 2.4 http://www.onlinedown.net/soft/47289.htm It does not recognize this format, so it cannot generate an IMG image, and of course it also cannot write it back to floppy; This software is very good for standard floppies. Too bad the author no longer updates it. It would be great if it were compatible with this format. rawwritewin 0.7 It can read out an IMG file, but after writing it back to a floppy, the floppy cannot be opened and prompts for formatting. FLOPPY IMGAGE 2.4.0 http://download.pchome.net/system/disk/detail-8678-1.html It can read it out and save it in IMG format, but it shows the size as 616k, even for a 1.232M floppy. Without formatting the target disk, it can write it back to the floppy. I first used the format command to format the floppy as 1.232M, then used this software to write it back without formatting. It could be opened and the files could be seen, but it could not boot. Under XP, if you right-click the floppy drive and click "Copy Disk", it can copy it, and after copying the two disks are exactly the same and can boot. So, what software can be used to save an IMG and write it back to a floppy? Thanks!jinkun23@sohu.com [ Last edited by zk9523 on 2010-5-16 at 16:36 ]

Floor2　wl00560	Posted 2010-05-15 19:53
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Haven't you tried HD-Copy?

Floor3　Climbing	Posted 2010-05-16 04:40
铂金会员　Posts 2,753　Credits 6,962　From 河北保定
Right, I also recommend using hd-copy. Also, one-to-one copying software like dd for win should not have any problem either.

Floor4　zk9523	Posted 2010-05-16 09:07
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Originally posted by wl00560 at 2010-5-15 07:53 PM: 没有试过HD-Copy？ HD-copy only supports 80-84 tracks, while NEC format is 77 tracks, so it is not supported and directly shows a disk error.

Floor5　lianjiang2004	Posted 2010-05-16 10:04
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It probably requires NEC-specific floppy disks and floppy drives. Ordinary floppy drives and floppy disks won't work.

Floor6　Climbing	Posted 2010-05-16 10:10
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@lianjiang Didn't the OP already say in the first post that Windows' disk copy function works?

Floor7　lianjiang2004	Posted 2010-05-17 10:19
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There is a tool here that supports the NEC format. You can give it a try: http://ftp.vector.co.jp/pack/dos/util/disk/fddiag03.lzh ------------------------------------------------------------------- FDDIAG A floppy disk maintenance program This program is for the NEC PC-9801 series, and performs sector-level read/write operations on floppy disks, as well as physical formatting of media on a track-by-track basis. When reading from or writing to files, it can also simultaneously convert between a block-structured fixed-length format and a text format editable with MS-DOS editors, and also perform code conversion to and from EBCDIC.

Floor8　zk9523	Posted 2010-05-18 07:31
新手上路　Posts 4　Credits 10
Originally posted by lianjiang2004 at 2010-5-17 10:19 AM: Here's a tool that supports NEC format. You can give it a try: http://ftp.vector.co.jp/pack/dos/util/disk/fddiag03.lzh ------------------------------------------------------------ ... Thank you! I downloaded it, but unfortunately I don't understand Japanese. I looked at it for a long time and still couldn't make sense of it. Could you please provide specific usage instructions? It would be best if you could give a simple explanation specifically for NEC format. Thanks again!