||Wed 2014-07-30 12:47|
|Yes, that is a good example!|
I don't know for sure why it's like that, but I'd have to suppose that it's some kind of a consequence of DOS's evolution from CP/M which had drive letters but not subdirectories. I bet it'll turn out something like: there was a big and important class of legacy CP/M programs that needed to be easy to port to DOS in order to make DOS sell, which expected to be able to keep opening
B:THAT.DAT, and so if you wanted to actually take advantage of DOS's directory system to keep all the data for those programs somewhere other than the root of your drive(s) then you needed to be able to set a separate persistent cwd per drive before running the legacy program.
Though I suppose even that only explains the idea of having a persistent per-drive cwd and hence some method for adjusting the directory for drive A without also making that the current drive. It still doesn't explain the bizarre idea that the default behaviour of
CD A:\THING ought to be to do that specialist operation...