Uncreative Labs

Joined: 21 Dec 2005 Posts: 66

For those of you running DOS 5 on an older machine, like a PC or an XT. (An AT is probably too fast.)

If you use it with a drive that is in the 60 to 100MB (or more) size range, do you notice long pauses after doing a directory or certain types of file accesses?

I'm using a pretty high performance 544MB SCSI disk carved up into 100MB partitions. It's being driven by a parallel-port to SCSI adapter on a PCjr using a bi-directional parallel port.

Usually after reading a directory for the first time DOS just kind of hangs, then comes back. The drive light is flashing, so I think it is computing the free disk space.

Has anybody else seen this?

Joined: 03 Dec 2005 Posts: 41 Location: Netherlands

Hey Mrbrutman, here too? Smile

I see this on xt's mainly (also with dos 3.3)

Joined: 21 Dec 2005 Posts: 66

We obsolete machine users are a limited group. Wink

I suspect it is a free space calculation doing this. I need to try it on a disk with smaller partitions to see if I can shrink the pause down. If I can, then I'll know what the source of the problem is.

Of course I can't figure out why DOS needs to keep refiguring the free space. You'd think it's in the FAT.

Joined: 22 Oct 2005 Posts: 61 Location: sunny AZ

like a couple seconds? sounds normal to me....

Posted: Tue Jan 03, 2006 12:23 am

I've noticed it. It always helped in being able to read so I didn't have to use the /w or /p switches.

This sounds interesting enough that perhaps Raymond Chen would care to comment on it in his blog. He does Windows history and Win32 programming entries (mainly) and it's usually an interesting read.

http://blogs.msdn.com/oldnewthing/default.aspx

Joined: 21 Dec 2005 Posts: 66

Hmm .. thought I replied, reply must have been eaten.

On my 8088 class machines with 60 to 100MB partitions the pause is more like 5 to 10 seconds. It is very noticable. If it were just 2 I wouldn't complain.

I'll check that blog out, although usually I avoid blogs like the plague. What the hell is a blog anyway .. I just call them web pages. Smile

Joined: 22 Oct 2005 Posts: 61 Location: sunny AZ

5 to 10 seconds on an 8088 is like a millisecond on a modern computer

Joined: 01 Oct 2004 Posts: 169 Location: behind you!

yep. Thats normal. I have a 1gig+ hard drive in my xt and it take a while to respond after a dir command. Seeing as I'm only using about 50mb I COULD drop in a smaller drive Very Happy

.

Joined: 02 Oct 2004 Posts: 594 Location: Western NC

Quote:

If you use it with a drive that is in the 60 to 100MB (or more) size range, do you notice long pauses after doing a directory or certain types of file accesses?

Yep, happened on DOS 6.22 and PC-DOS 2K

Hmm, and I thought it was the crappy IDE controller-card I was using....

Posted: Tue Jan 03, 2006 1:11 pm

I'm going to install Windows 95 on a virtual machine and see what happens at the command line.

I got 98 installed, so I'll give that a try too.

Posted: Tue Jan 03, 2006 1:40 pm

Ok, looks like '98's command.com does it, so does XP's. I'm playing with getting Win95 installed on a Virtual PC, but without a disk image or real floppy drive it's difficult. (USB sticks come along and cause the abandonment of the oldest, most reliable computer hardware component there is!)

Here's something about calculating the size of a directory:
http://blogs.msdn.com/oldnewthing/archive/2004/12/28/336219.aspx

Guest

i considered my xt clone to be " peppy" as i set everything to run efficiently
( not being able to afford anything faster)
the FIRST time i noted a real delay ( the pc thinking) was when i zipped a fairly large file.
also when I saved a 1-2 meg text file in wordstar 3 or 4, I went and had supper, as it was slow.

Guest

I asked this question long ago in the old forum and no one seemed to know the answer. I too have noticed that a dir command results in a delay command then a dir.

Joined: 03 Dec 2005 Posts: 41 Location: Netherlands

does dir/W does it too?

Posted: Thu Jan 19, 2006 4:12 am

The pause is DOS calculating the amount of free space on the drive, to do which it has to scan through the entire FAT counting the number of free entries.

Later versions of DOS (but I couldn't say where, exactly) cached an _approximate_ free space amount to avoid this delay at the expense of slightly inaccurate or out-of-date display.