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Copyright (C) 1987, the Disk Doctor.
First published in the Rochester (PC)^3 News:
Picture City PC Programming Club
PO BOX 20342
Rochester, NY 14602
The Disk Doctor may be contacted at this
address, or via CIS [73147,414].
This material may be reproduced for internal
use by other not-for-profit groups, provided
this copyright notice is included.
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1:45pm
"I'm MAD as hell, and I'm not going to
TAKE it anymore!"
My friend, H., has a tendency to over-
react to any situation involving his PC.
If you just ignore his temper tantrums,
eventually he will calm down. Without
looking up from my keyboard, I told him to
come in and sit down. "Tell me what's on
your mind."
"Dag-nab it. I hate having to swap disks
all the time. All I want to do is to make
this program self-booting, so I can put
away my DOS disk. But no matter what I
try, I can't get the fool thing to work."
He was pacing back and forth ,waving his
arms in the air.
"Sit down," I gestured towards a chair.
The potentially violent client is always
less threatening in a seated position.
The split-second it takes to rise to one's
feet is sufficient time to afford escape
to the besieged party. "Tell me what
happened."
"I began by copying COMMAND.COM to my
program disk. But that didn't work. It
just hung up my machine and gave me a
'Non-system disk' message."
"That's right. You see, there are 3 files
that make up the DOS operating system.
In addition to COMMAND.COM, there is
IBMBIO.COM and IBMDOS.COM."
H. tried to repeat the names I had just
rattled off. "What's IBM-BUYOUT DOTCOM?"
"No. IBM-B-I-O."
"Is that like Biorhythms?"
I laughed. I could see that H. was
finally calming down. He enjoys poking
fun at my knowledge of the IBM PC.
"Actually, it's short for BIOS, Basic
Input & Output System, the fundamental
part of the DOS operating system."
"So I should have copied those two files
as well?"
"No, it's not that simple. In order to
work right, IBMBIO.COM and IBMDOS.COM must
be in a particular place on the diskette,
in the sectors immediately following the
directory."
"How come I've never seen those other
files listed in my DIRectory?."
"They're marked hidden in the file
directory, so you can't accidently delete
or modify them. Hidden files can't be
copied by the COPY command, either."
"How are you supposed to copy them, then?"
1:50pm
I explained. "Well, one way is to use
DISKCOPY. This command copies an entire
disk, including hidden files."
"Hold it. Hold on just one minute.
I tried DISKCOPY, but that didn't work
either."
"How so?"
"I copied my DOS disk with DISKCOPY, and
erased all the programs I didn't need,
like BASIC, FORMAT, and so on. Then, when
I tried to copy over all my program files,
it said 'Disk full' or something like
that. Even after I erased everything on
the copy disk, there was only 150 K of
free space. This computer stuff is just
too complicated for me..."
"Okay, now. I see what happened. The
reason there's no room on the disk is that
it is formatted single-sided..."
"No, Doc, I'm always careful to only buy
double-sided diskettes..."
"...Now, let me finish," I interrupted.
"The DOS diskette itself is single-sided.
It doesn't matter which kind of diskette
you use, when you DISKCOPY a single-sided
disk, you got a single-sided copy. So you
started out with 180 KB, and after you
deleted everything but the hidden files
(which can't be erased with DEL), you were
left with only 150 KB."
"How come DOS is provided on single-sided
diskettes? Everyone I know uses double-
sided disks."
"That's for the poor guys stuck with the
original model of the IBM-PC, which was
built with single-sided drives."
"Okay, Mr. Smart Guy, what should I have
done?"
1:52pm
"The simplest way to make a bootable disk,
is to FORMAT a new disk with the /S option
(for system). This puts the three
operating system files on the beginning of
a new disk. Then copy the program files
on to this disk."
I continued, "Sometimes, with copy-
protected software, you can't make a copy.
Or the copy you make won't run without the
key disk in drive A:. In that case, read
the instructions. A lot of those disks
can still be made bootable using the SYS
command, which you will find on the DOS
disk. But SYS only works if the
manufacturer formatted the disk in a
certain way, with enough room left at the
beginning for the operating system."
"Then why doesn't the manufacturer just
put the operating system on the disk?"
"Well, because some people run PC-DOS,
and some run MS-DOS. Some use DOS 2.0,
some use 3.0, and some are still using
1.0. Anyways, the software manufacturer
can't ship the operating system without
a license from Microsoft and/or IBM."
"Thanks, Doc. I never really understood
all that stuff before. Sorry I was so
rough on you there."
"It's alright. You're always welcome to
stop in with a disk problem. I think a
little education goes a long way towards
making people more comfortable with their
PC."
