At least one CP/M command also survived into MS/DOS.
I recall a late 1980s misbehaving Toshiba plasma-screen laptop PC (high-end,
it had an 80486 chip!) which seemed not to recognise that files had been
copied between its A and B floppy drives (only one physical drive, swapping
floppy disks in and out) - though another laptop would show them in the
directory listing of the same floppies.
Could it be that the hardware disk-change sensing switch was faulty? Because
CP/M didn't have such a thing, you had to tell CP/M when you changed floppy
disks, "Ctrl-c - change disk".
To my amazement, the command still worked in MS-DOS, forcing the PC to
re-read the directory. That was a very confusing moment, I can tell you.
Piers
-----Original Message-----
From: Chuck Norcutt [mailto:chucknorcutt@xxxxxxxxxxxxxxxx]
Sent: 19 December 2008 13:32
To: Olympus Camera Discussion
Subject: Re: [OM] While on the subject of computer safety and back-ups
CP/M existed before IBM PC/DOS which existed before MS/DOS although the
latter two are essentially the same. CP/M was also available for the IBM PC
on the day of announcement but the cost was $250 vs about $60 for PC/DOS.
Not hard to guess which one survived.
Chuck Norcutt
Chris Barker wrote:
> It was CP/M, Frank; I had to search for it on the Web. It was a
> command-line system with commands similar to MSDOS.
>
> Chris
>
> On 19 Dec 2008, at 10:28, Frank van Lindert wrote:
>
>> Dr DOS? Concurrent DOS? QDOS (Quick and Dirty DOS? 86-DOS?
>>
>> BTWQ, it might interest you that one of the first disk operating
>> systems was mad by... Apple. At least according to this link
>> http://members.fortunecity.com/pcmuseum/dos.htm , FWIW.
>>
>> Frank van Lindert
>> Utrecht NL.
>>
>>
>>
>> Fri, 19 Dec 2008 09:46:47 +0000, Chris Barker <ftog@xxxxxxxxxxxxxx>
>> wrote:
>>
>>> Winchester drives! It was a machine with a 20Mb Winchester on which
>>> I learned about personal computing. It was connected (in 1986/7) to
>>> a computer running an OS whose name now escapes me: a DOS but not PC
>>> DOS or MSDOS.
>
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|