Why is the Hard Drive called "C" by default?

Is there a historical/technical reason why the Hard Drive called "C" by
default? Why is it not called "A" (since it is the primary mass storage
device on many computer configurations)? What about the "B" drive? Just
curious about this.....

Thanks in advance

wrote in message
ps.com...
Is there a historical/technical reason why the Hard Drive called "C" by
default? Why is it not called "A" (since it is the primary mass storage
device on many computer configurations)? What about the "B" drive? Just
curious about this.....

Thanks in advance

Short answer: Historical
Long answer: The first Personal Computers had a single floppy drive (Drive
"A").
Users booted from a floppy disk, popped that disk out and inserted a floppy
disk which contained the computer program that the user desired to use.
Some people wanted to keep their data on a floppy disk "other" than the
"program" disk. They grew tired of the "floppy disk shuffle" and put a
second floppy drive into their computers, ("Drive "B").
Well after hard disks became ubiquitous in PCs, the floppy disk began
transitioning from size 5 1/4" to size 3 1/2" . For several years during
that transition phase, many people required a floppy drive of each size in
order to access older programs/data on the old size disks and their new
programs on the new size disks.
Steve

You call that historical? How old are you? You know there were floppy
disks before 5 1/4" disks?

Anyway, yes A and B were used for floppy drives. As of about 10 years ago,
all computers came with 3.5" drives, many with 2 3.5" drives for easy
copying of one floppy disk to another, and they were starting to get CD
drives at the same time. So the CD drives ended up being called E or F if
you had 2 hard drives. Now that we can write to CDs and even DVDs, we don't
really use 3.5" disks anymore. So hard drives still start at C, CD drives
still start at E/F, and A and B are generally not used in new computers.

"Og" wrote in message
...
wrote in message
ps.com...
Is there a historical/technical reason why the Hard Drive called "C" by
default? Why is it not called "A" (since it is the primary mass storage
device on many computer configurations)? What about the "B" drive? Just
curious about this.....

Thanks in advance

Short answer: Historical
Long answer: The first Personal Computers had a single floppy drive (Drive
"A").
Users booted from a floppy disk, popped that disk out and inserted a
floppy disk which contained the computer program that the user desired to
use.
Some people wanted to keep their data on a floppy disk "other" than the
"program" disk. They grew tired of the "floppy disk shuffle" and put a
second floppy drive into their computers, ("Drive "B").
Well after hard disks became ubiquitous in PCs, the floppy disk began
transitioning from size 5 1/4" to size 3 1/2" . For several years during
that transition phase, many people required a floppy drive of each size in
order to access older programs/data on the old size disks and their new
programs on the new size disks.
Steve

Try this

http://inventors.about.com/library/weekly/aa031599.htm

"The first IBM PC ran on a 4.77 MHz Intel 8088 microprocessor. The PC
came equipped with 16 kilobytes of memory, expandable to 256k. The PC
came with one or two 160k floppy disk drives and an optional color monitor."



Eric wrote:

You call that historical? How old are you? You know there were floppy
disks before 5 1/4" disks?

Anyway, yes A and B were used for floppy drives. As of about 10 years ago,
all computers came with 3.5" drives, many with 2 3.5" drives for easy
copying of one floppy disk to another, and they were starting to get CD
drives at the same time. So the CD drives ended up being called E or F if
you had 2 hard drives. Now that we can write to CDs and even DVDs, we don't
really use 3.5" disks anymore. So hard drives still start at C, CD drives
still start at E/F, and A and B are generally not used in new computers.

"Og" wrote in message
...

wrote in message
oups.com...

Is there a historical/technical reason why the Hard Drive called "C" by
default? Why is it not called "A" (since it is the primary mass storage
device on many computer configurations)? What about the "B" drive? Just
curious about this.....

Thanks in advance


Short answer: Historical
Long answer: The first Personal Computers had a single floppy drive (Drive
"A").
Users booted from a floppy disk, popped that disk out and inserted a
floppy disk which contained the computer program that the user desired to
use.
Some people wanted to keep their data on a floppy disk "other" than the
"program" disk. They grew tired of the "floppy disk shuffle" and put a
second floppy drive into their computers, ("Drive "B").
Well after hard disks became ubiquitous in PCs, the floppy disk began
transitioning from size 5 1/4" to size 3 1/2" . For several years during
that transition phase, many people required a floppy drive of each size in
order to access older programs/data on the old size disks and their new
programs on the new size disks.
Steve

wrote in message
ps.com...
Is there a historical/technical reason why the Hard Drive called "C" by
default? Why is it not called "A" (since it is the primary mass storage
device on many computer configurations)? What about the "B" drive? Just
curious about this.....

Thanks in advance


Before bootable CD drives came along, floppy drives were provided with
letters A and B. Now, either the bootable CD or floppy may take A.

The next sequential letter is C. This is usually the first active, primary
partition found on a hard drive. Its also dependent on the
active/primary/logical partition hierarchy scheme system. Its possible to
boot from floppy or CD, and a logical partition may take drive letter C, if
no primary partitions exist for instance.

Originally, PCs had no hard drives. They ran on big oversize floppies. B
designation came later, and was commonly used as a data diskette. The hard
drive came along, and logically, its partition took the letter C.

A cd drive can take the letter C, if no detectible hard drive partition
exists. Designating a latter letter for the cd drive with driver modifier
is the typical solution used. This is only seen with floppy boot media like
a 98 startup diskette for instance. The former can be seen, under the right
conditions, with a simple boot diskette.

Magneto floppies (if not bootable), pen drives, CD/DVD and so forth follow a
letter hierarchy specific to windows. And in some cases, can be modified by
the user. With the advent of XP, even more latitude is provided for drive
letter changes by the user.
--
Jonny

On 28 Aug 2006 22:41:22 -0700, wrote:

Is there a historical/technical reason why the Hard Drive called "C" by
default? Why is it not called "A" (since it is the primary mass storage
device on many computer configurations)? What about the "B" drive? Just
curious about this.....

Thanks in advance

Because in the old days there were usually two floppies.

True - and prior to THAT there were the Altair and the Imsai 8080 using the
8080 chip. Input on the IMSAI was via 16 paddle switches on the front.
Output was via the LED's - 16 of them. You input and read data two bytes at
a time. BTW, those 160k floppy's were 8" discs. I developed the firmware for
the first double density controller - got a whopping 320k out of an 8"
floppy.

"Bob I" wrote in message
...
Try this

http://inventors.about.com/library/weekly/aa031599.htm

"The first IBM PC ran on a 4.77 MHz Intel 8088 microprocessor. The PC came
equipped with 16 kilobytes of memory, expandable to 256k. The PC came with
one or two 160k floppy disk drives and an optional color monitor."



Eric wrote:

You call that historical? How old are you? You know there were floppy
disks before 5 1/4" disks?

Anyway, yes A and B were used for floppy drives. As of about 10 years
ago, all computers came with 3.5" drives, many with 2 3.5" drives for
easy copying of one floppy disk to another, and they were starting to get
CD drives at the same time. So the CD drives ended up being called E or
F if you had 2 hard drives. Now that we can write to CDs and even DVDs,
we don't really use 3.5" disks anymore. So hard drives still start at C,
CD drives still start at E/F, and A and B are generally not used in new
computers.

"Og" wrote in message
...

wrote in message
roups.com...

Is there a historical/technical reason why the Hard Drive called "C" by
default? Why is it not called "A" (since it is the primary mass storage
device on many computer configurations)? What about the "B" drive? Just
curious about this.....

Thanks in advance


Short answer: Historical
Long answer: The first Personal Computers had a single floppy drive
(Drive "A").
Users booted from a floppy disk, popped that disk out and inserted a
floppy disk which contained the computer program that the user desired to
use.
Some people wanted to keep their data on a floppy disk "other" than the
"program" disk. They grew tired of the "floppy disk shuffle" and put a
second floppy drive into their computers, ("Drive "B").
Well after hard disks became ubiquitous in PCs, the floppy disk began
transitioning from size 5 1/4" to size 3 1/2" . For several years during
that transition phase, many people required a floppy drive of each size
in order to access older programs/data on the old size disks and their
new programs on the new size disks.
Steve

Vic Baron wrote:
True - and prior to THAT there were the Altair and the Imsai 8080
using the 8080 chip. Input on the IMSAI was via 16 paddle switches on
the front. Output was via the LED's - 16 of them. You input and read
data two bytes at a time.

BTW, those 160k floppy's were 8" discs. I

Wrong! The floppies on the original IBM PC were 5.25" 160kB
The 8" floppies are from a earlier era



developed the firmware for the first double density controller - got
a whopping 320k out of an 8" floppy.

"Bob I" wrote in message
...
Try this

http://inventors.about.com/library/weekly/aa031599.htm

"The first IBM PC ran on a 4.77 MHz Intel 8088 microprocessor. The
PC came equipped with 16 kilobytes of memory, expandable to 256k.
The PC came with one or two 160k floppy disk drives and an optional
color monitor." Eric wrote:

You call that historical? How old are you? You know there were
floppy disks before 5 1/4" disks?

Anyway, yes A and B were used for floppy drives. As of about 10
years ago, all computers came with 3.5" drives, many with 2 3.5"
drives for easy copying of one floppy disk to another, and they
were starting to get CD drives at the same time. So the CD drives
ended up being called E or F if you had 2 hard drives. Now that we
can write to CDs and even DVDs, we don't really use 3.5" disks
anymore. So hard drives still start at C, CD drives still start at
E/F, and A and B are generally not used in new computers.

"Og" wrote in message
...

wrote in message
ps.com...

Is there a historical/technical reason why the Hard Drive called
"C" by default? Why is it not called "A" (since it is the primary
mass storage device on many computer configurations)? What about
the "B" drive? Just curious about this.....

Thanks in advance


Short answer: Historical
Long answer: The first Personal Computers had a single floppy drive
(Drive "A").
Users booted from a floppy disk, popped that disk out and inserted
a floppy disk which contained the computer program that the user
desired to use.
Some people wanted to keep their data on a floppy disk "other"
than the "program" disk. They grew tired of the "floppy disk
shuffle" and put a second floppy drive into their computers,
("Drive "B"). Well after hard disks became ubiquitous in PCs, the
floppy disk
began transitioning from size 5 1/4" to size 3 1/2" . For several
years during that transition phase, many people required a floppy
drive of each size in order to access older programs/data on the
old size disks and their new programs on the new size disks.
Steve

"Thomas Wendell" wrote in message
...

Vic Baron wrote:
True - and prior to THAT there were the Altair and the Imsai 8080
using the 8080 chip. Input on the IMSAI was via 16 paddle switches on
the front. Output was via the LED's - 16 of them. You input and read
data two bytes at a time.

BTW, those 160k floppy's were 8" discs. I

Wrong! The floppies on the original IBM PC were 5.25" 160kB
The 8" floppies are from a earlier era


IBM used 8inch disks on their "DisplayWriter" word processors, but the
first IBM PC that landed in our office in around 1983 was 5-1/4. It was a
disgraceful piece of engineering by standards of the day.

Bear in mind that 8086 processors were being shipped in 1978/9 and the 486
AN's were about in 83/84 it was a stone age piece of kit.

Steve

Steve

"Steve" steve wrote:


IBM used 8inch disks on their "DisplayWriter" word processors, but the
first IBM PC that landed in our office in around 1983 was 5-1/4. It was a
disgraceful piece of engineering by standards of the day.

Bear in mind that 8086 processors were being shipped in 1978/9 and the 486
AN's were about in 83/84 it was a stone age piece of kit.


Not quite correct. Intel released the first 80486 models in 1989.

In 1983/84 the highest performing x86 processor from Intel was the
80286. The 80386 was first marketed in 1986.

Ron Martell Duncan B.C. Canada
--
Microsoft MVP (1997 - 2006)
On-Line Help Computer Service
http://onlinehelp.bc.ca
Syberfix Remote Computer Repair

"Anyone who thinks that they are too small to make a difference
has never been in bed with a mosquito."

"Ron Martell" wrote in message
...
"Steve" steve wrote:


IBM used 8inch disks on their "DisplayWriter" word processors, but the
first IBM PC that landed in our office in around 1983 was 5-1/4. It was a
disgraceful piece of engineering by standards of the day.

Bear in mind that 8086 processors were being shipped in 1978/9 and the 486
AN's were about in 83/84 it was a stone age piece of kit.


Not quite correct. Intel released the first 80486 models in 1989.

In 1983/84 the highest performing x86 processor from Intel was the
80286. The 80386 was first marketed in 1986.


I think his point was that the processors were mature when they finally went
into PCs. IIRC the issues at the time were chipsets, which were very
expensive and complicated to design and produce...thus the 386sx...a 386
that ran on a 286 chipset.

-John O

"JohnO" wrote:



I think his point was that the processors were mature when they finally went
into PCs. IIRC the issues at the time were chipsets, which were very
expensive and complicated to design and produce...thus the 386sx...a 386
that ran on a 286 chipset.

-John O


Intel may have waited a few months for supporting chipsets to be
developed but not much more than that. The first functioning models
of the 80486 were not even developed in the Intel labs until 1988 at
the earliest.

As for the 386SX my recollection was that it was more a case of
motherboard design and RAM quantity than the supporting chipset. 0286
motherboard designs were readily adaptable to the 386sx, and the 16
bit data path meant that only two 30 pin SIMMs were needed rather than
the four required by the 32 bit data path in the full 80386. That was
a big factor for the laptop manufacturers in particular, as the extra
SIMM sockets meant increased size and weight which are major concerns
with laptop design.

Ron Martell Duncan B.C. Canada
--
Microsoft MVP (1997 - 2006)
On-Line Help Computer Service
http://onlinehelp.bc.ca
Syberfix Remote Computer Repair

"Anyone who thinks that they are too small to make a difference
has never been in bed with a mosquito."