Pair of Twiggys

[Fred Cisin]

On Wed, 15 Mar 2017, Chuck Guzis via cctalk wrote:
> The whole idea of an "operating system"  seems to have morphed into the
> notion of a user interface.
> To my way of thinking,t he various flavors of Linux are really a user
> interface build on a single operating system.
> I recall that back in the days of Windows 95, MS defended it as an
> "operating system" (re: the default inclusion of MSIE in the same),
> rather than a user interface built on top of MSDOS.
> I once had a fellow proclaim that his group had constructed an entire
> operating system in COBOL.  When I asked him about his file management,
> he said that it was handled by the kernel and not the operating system.

I used to teach a beginning microcomputer operating system class.
The administration wanted it to be remedial job training for the digital 
sweatshop, and never go past what commands do you do to format a disk, 
etc., and called for discontinuing the class once Windoze95 came out.
I tried, instead, to create an understanding of what an OS was, as well as 
how to use it, and how to deal with problems.  I dealt with 
sector editing repair of directories, etc.
(In creatively handling user interface problems, I had a test question of: 
"You have a PC-DOS 3.30 PS/2 with a damaged keyboard (Pepsi Syndrome). 
There are other computers handy, but no other keyboards with the right 
connector.  The 'A', 'C', and 'D' keys won't work!  List some ways that 
you can copy files from the hard disk onto floppies")
Among the answers that I would accept were: using <Alt> and the numeric 
pad, creating a batch file on another computer, even "REN X?OPY.EXE 
XBOPY.EXE".  One fellow included enough detail about cleaning key contacts 
and/or splicing the keyboard cable onto another one that I accepted that.
I even accepted a moderately detailed description of how to remove the 
hard disk and connect it as temporary second HDD on another computer.
(definitely a question of come up with a way, not "single right answer")


I started the internals discussions with "DOS est omnis divisa in 
partes tres", and wrote on the board:
BIOS(usually ROM)/BDOS/CCP (Console Command Processor) 
ROM&IO.SYS/MSDOS.SYS/COMMAND.COM
ROM&IBMBIO.COM/IBMDOS.COM/COMMAND.COM
hardware interface/file management/user interface

We then spent some time on what each of those parts was.

It doesn't HAVE TO be three parts, but those are a reasonable division.


I loved how PC-DOS 1.00 documentation included partial description of what 
was needed to write a replacement command processor!


> One thing you can depend upon in this field is the inconstancy of
> definitions.

Sometimes I think that it is NIH ("Not Invented Here"), but it seems as 
though a lot of people invent new names for the same things.
block/cluster/granule, etc.


> I always wondered about the wisdom of single-sourcing storage devices
> such as the Next optical drive, the Twiggy or the SuperDrive of the
> early Macs.

I was surprised that Jobs didn't make the Lisa floppy 5.0 or 5.5 inches,
and used a relatively standard drive for the Mac.  I would have thought 
that he would want people to buy even their media from Apple.
For people who think that that is absurd, remember that there have been 
more than one machine that was capable of formatting it's own diskettes, 
but was not supplied with a FORMAT program.


--
Grumpy Ol' Fred     		cisin at xenosoft.com