4 ms·

DOS was essentially a clone of CP/M, which did not have a hierarchical directory structure either. When the main form of storage were floppy disks which only he

by ch_123 5y ago

DOS was essentially a clone of CP/M, which did not have a hierarchical directory structure either. When the main form of storage were floppy disks which only held a few hundred KB, you generally didn't have enough files to need a directory hierachy. The addition of hierarchical directories to DOS was driven by the inclusion of hard drives in the PC XT.

bombcar 5y ago
In fact floppies themselves were the folders - you'd have a box of floppies on your desk and pick the one you needed for whatever you were working on.
p_l 5y ago
Apparently it took DOS 2.0 copying ideas from Unix (which was also being sold by Microsoft) like hierarchical directories or pipes, that made DOS win over CP/M-86 by anything other than "it's included by default, most of the time". At the time, there was strong danger that the well known and accepted CP/M could make a comeback on PC.
- rep_lodsb 5y ago
  DOS 2.0 was originally supposed to be a single-user version of Xenix. There were some undocumented options to make it more Unix-like, which were removed in later versions: https://www.youtube.com/watch?v=Vo8NG8T4rWs https://www.youtube.com/watch?v=Vo8NG8T4rWs The connection with Xenix is also pretty clear from the file names and comments in the released source code: https://github.com/microsoft/MS-DOS/blob/master/v2.0/source/XENIX.ASM https://github.com/microsoft/MS-DOS/blob/master/v2.0/source/... https://github.com/microsoft/MS-DOS/blob/master/v2.0/source/XENIX2.ASM https://github.com/microsoft/MS-DOS/blob/master/v2.0/source/...
  - PopAlongKid 5y ago
    I don't need to watch the video to know that two of these options were entries in CONFIG.SYS, one of them "SWITCHAR" as I recall. It would cause DOS to use forward slash instead of backslash for separating components of a pathname, and it would use hyphens instead of forward slashes for command line options, both just like Unix.
    - rep_lodsb 5y ago
      You are correct, and the other one is AVAILDEV. Set it to false, and device names like CON only refer to the device when prefixed with "/dev/". Microsoft did have a reason to remove these features: compatibility with batch files. "\dev\" actually remained special in all later versions, in that it can always be used to open a device, even if that directory doesn't exist. This could break a common idiom in batch files to test if a path is valid: C:\> if exist \dev\nul echo Yup, still there (I don't have a recent version of Windows to test this on, interested to see if it still works!)

by ch_123 5y ago

bombcar 5y ago

In fact floppies themselves were the folders - you'd have a box of floppies on your desk and pick the one you needed for whatever you were working on.

p_l 5y ago

Apparently it took DOS 2.0 copying ideas from Unix (which was also being sold by Microsoft) like hierarchical directories or pipes, that made DOS win over CP/M-86 by anything other than "it's included by default, most of the time". At the time, there was strong danger that the well known and accepted CP/M could make a comeback on PC.

rep_lodsb 5y ago
DOS 2.0 was originally supposed to be a single-user version of Xenix. There were some undocumented options to make it more Unix-like, which were removed in later versions: https://www.youtube.com/watch?v=Vo8NG8T4rWs https://www.youtube.com/watch?v=Vo8NG8T4rWs The connection with Xenix is also pretty clear from the file names and comments in the released source code: https://github.com/microsoft/MS-DOS/blob/master/v2.0/source/XENIX.ASM https://github.com/microsoft/MS-DOS/blob/master/v2.0/source/... https://github.com/microsoft/MS-DOS/blob/master/v2.0/source/XENIX2.ASM https://github.com/microsoft/MS-DOS/blob/master/v2.0/source/...
- PopAlongKid 5y ago
  I don't need to watch the video to know that two of these options were entries in CONFIG.SYS, one of them "SWITCHAR" as I recall. It would cause DOS to use forward slash instead of backslash for separating components of a pathname, and it would use hyphens instead of forward slashes for command line options, both just like Unix.
  - rep_lodsb 5y ago
    You are correct, and the other one is AVAILDEV. Set it to false, and device names like CON only refer to the device when prefixed with "/dev/". Microsoft did have a reason to remove these features: compatibility with batch files. "\dev\" actually remained special in all later versions, in that it can always be used to open a device, even if that directory doesn't exist. This could break a common idiom in batch files to test if a path is valid: C:\> if exist \dev\nul echo Yup, still there (I don't have a recent version of Windows to test this on, interested to see if it still works!)