Computer Hope

Microsoft => Microsoft DOS => Topic started by: chris70 on August 24, 2017, 09:05:58 AM

Title: one disk drive
Post by: chris70 on August 24, 2017, 09:05:58 AM
How to write commands to ms dos when it has one disk drive on the computer
For example if i want to run scandisk and check another floppy then what i write?

Title: Re: one disk drive
Post by: DaveLembke on August 24, 2017, 11:09:41 AM
So this computer only has a single floppy drive and no hard drive?
Title: Re: one disk drive
Post by: chris70 on August 24, 2017, 11:46:46 AM
If i have ms dos on bootable floppy disk 1.44 and load system of this how i can work in another floppy disk ?
for example     a:\>  and i want copy file or scandisk in floppy without ms-dos ?
Title: Re: one disk drive
Post by: Salmon Trout on August 24, 2017, 01:04:27 PM
Under MS-DOS since v5,  in a 2 floppy drive system, the drives are A: and B:, if there is only one floppy drive it will be A: at boot, but if you specify B:, the system will prompt you to insert another floppy disk and will consider itself logged in to that drive letter (show that letter at the prompt etc) until you switch back again.

Quote
MS-DOS/PC DOS since version 5.0, and later operating systems, assigns drive letters according to the following algorithm:

Assign the drive letter A: to the first floppy disk drive (drive 0), and B: to the second floppy disk drive (drive 1). If only one physical floppy is present, drive B: will be assigned to a phantom floppy drive mapped to the same physical drive and dynamically assigned to either A: or B: for easier floppy file operations.


Title: Re: one disk drive
Post by: patio on August 24, 2017, 01:04:33 PM
You can't do what you want with only 1 drive...period.
Title: Re: one disk drive
Post by: Salmon Trout on August 24, 2017, 01:10:08 PM
You can't do what you want with only 1 drive...period.
Are you sure?
Title: Re: one disk drive
Post by: DaveLembke on August 24, 2017, 01:55:55 PM
A RAMDrive could be created and scandisk copied to that if it fits within the limited size of the RAM Drive. This allocates a section of RAM to act as a virtual hard drive. You can then scan disk the next disk in the drive from say the RAMDisk drive of E: So from E: you would run scandisk A: or with whichever switches you want to use with it for disks placed into A:

https://books.google.com/books?id=u7oN-5y7nGsC&pg=PA175&lpg=PA175&dq=ramdrive.sys+dos&source=bl&ots=j6i62HQrs-&sig=flW8BOAJYi7Kc36RcrqXlSDNN9o&hl=en&sa=X&ved=0ahUKEwjn-s_g0vDVAhXG7YMKHUUwBHgQ6AEIUjAH#v=onepage&q=ramdrive.sys%20dos&f=false


You need a bootable floppy with DOS 6.22, then configure it for the RAMDRIVE to be active at next boot. Reboot computer and RAM Drive is created. Next copy scandisk to the RAM Drive such as at letter E: and then remove the bootable floppy from A: and insert the disk you want to scan into the drive at A: and from E: run scandisk with whatever switches if any and A:


*Is this a homework project?

In regards to what salmon said... I do recall many years ago being able to call to a single drive at both A: and B: and it read the disk and I never understood why. I thought that it was messed up somehow since only 1 drive was present. Curious how the A: to B: method would work in a single drive system since the disk removed would take scandisk away with it. RAMDrive is only method I can think of to make this work with scandisk remaining in RAM to be called.  :-\
Title: Re: one disk drive
Post by: patio on August 24, 2017, 02:16:54 PM
Are you sure?

He never stated 2 drives...so i'll stick to what i stated...unless we get the full story...
Title: Re: one disk drive
Post by: BC_Programmer on August 24, 2017, 03:07:35 PM
Salmon Trout's method works. I wasn't familiar with it so I just gave it a shot in VMWare under MS-DOS 6.22.

The VM I have only has one floppy drive. I was able to use chkdsk on a bootable floppy image and run it against a separate image that had only data files using the "Phantom drive" approach.

A simple "scandisk B:" when A: is the current drive seemed to do the trick. It prompted for the disk for B:, and I swapped in the data diskette.

LKooks like you can also change to the data diskette directly via B: and then run A:\scandisk B: and it prompts for the A: diskette, then the B: Diskette, and the program runs against B:.
Title: Re: one disk drive
Post by: Salmon Trout on August 24, 2017, 03:49:45 PM
I can still remember when I upgraded my Epson Equity II XT PC from MS-DOS version v3.3 to v5.0, thanks to a pal who had a spare set of 5.25" floppies. QBasic! the editor! And of course the phantom floppy thing I mentioned above. It had one 5.25" 360K floppy drive. You could run WordPerfect off A: and keep your documents on B: , and the system told you when to swap the disks.
(https://thumbs.ebaystatic.com/d/l225/m/mI08rC1hSYV4UkJuc52SiHw.jpg)
Title: Re: one disk drive
Post by: chris70 on August 24, 2017, 04:58:23 PM
Salmon Trout's method works. I wasn't familiar with it so I just gave it a shot in VMWare under MS-DOS 6.22.

The VM I have only has one floppy drive. I was able to use chkdsk on a bootable floppy image and run it against a separate image that had only data files using the "Phantom drive" approach.

A simple "scandisk B:" when A: is the current drive seemed to do the trick. It prompted for the disk for B:, and I swapped in the data diskette.

LKooks like you can also change to the data diskette directly via B: and then run A:\scandisk B: and it prompts for the A: diskette, then the B: Diskette, and the program runs against B:.


!!!!!!!!!!!!!!!!!
Title: Re: one disk drive
Post by: DaveLembke on August 25, 2017, 06:01:11 AM
Very Cool on the A: (Phantom B:) approach. Easier than a RAMDrive and your method supports older DOS than 6.22 also.   8)