Origin or 1.44 MV FD label [WAS: RE: Weekly Classic Computer Trivia Question (20141205)]
7 Dec
2014
7 Dec
'14
12:46 p.m.
-----Original Message-----
From: Fred Cisin [mailto:cisin at xenosoft.com]
Sent: Saturday, December 06, 2014 12:40 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Weekly Classic Computer Trivia Question (20141205)
>On Sat, 6 Dec 2014, Johnny Billquist wrote:
> I should actually do my math before commenting. :-) It just happens,
> that by a funny accident, 1440*1024 is actually 1,474,560.
>
> But still. The actual size of the floppy wasn't decided because you
> pulled out 1440*1024, but because of the format of the darn thing.
> 1.44MB is just the closest "nice" number you can come up with after
> the fact as a way to talk about the capacity of the thing.
>
> It is not an exact number, but they seldom are, when we talk about
> storage. People like to round things off, to make it easier to talk
about.
It is NOT a "nice" number.
Honest numbers would be either 1.47 or 1.4 There is no legitimate way to
come up
with 1.44 unless you cheat and MIX powers of 10 and powers of 2.
__________________
It comes from a double capacity 720 KB FDD - which in this case are actually
KiB and not kB
However, in an incredible bit of marketing stupidity it was labeled 1.44 MB,
since 2*720 KB/1000 = 1.44 MB
Tom
7 Dec
7 Dec
12:56 p.m.
> It is NOT a "nice" number. Honest
numbers would be either 1.47 or 1.4
> There is no legitimate way to come up with 1.44 unless you cheat and
> MIX powers of 10 and powers of 2.
On Sun, 7 Dec 2014, Tom Gardner wrote:
It comes from a double capacity 720 KB FDD - which in
this case are actually
KiB and not kB
However, in an incredible bit of marketing stupidity it was labeled 1.44 MB,
since 2*720 KB/1000 = 1.44 MB
. . . and what justifies a division by 1000, when the existing number is
explicitly a multiple of 1024?
720K is NOT 0.72M
The disk is 1440 K, which is NOT 1.44M, it is 1.40625M,
or simply "1.4M".
Was it an ERROR? Or the work of cheating assholes?
1:29 p.m.
On 12/07/2014 12:56 PM, Fred Cisin wrote:
The disk is 1440 K, which is NOT 1.44M, it is
1.40625M,
or simply "1.4M".
Was it an ERROR? Or the work of cheating assholes?
Who's cheating? The maker of your formatting program? (Reaches over to
the top of his PC and grabs a high-density 3.5" floppy) I see three
lines of writing on the shutter.
Line 1: "IMATION"
Line 2: "2HD"
Line 3: "2.0 MB"
And, as I pointed out, at the customary western high-density clock rate
of 500KHz and 300 RPM rotation--and 8 bit bytes, comes out to exactly
2,000,000 bytes.
Don't blame the manufacturer for getting less than you bargained for.
It's very clear that "2.0 MB" means 2 x 10**6 bytes.
--Chuck
2:35 p.m.
> The disk is 1440 K, which is NOT 1.44M, it is
1.40625M,
> or simply "1.4M".
> Was it an ERROR? Or the work of cheating assholes?
On Sun, 7 Dec 2014, Chuck Guzis wrote:
Who's cheating? The maker of your formatting
program? (Reaches over to
the top of his PC and grabs a high-density 3.5" floppy) I see three
lines of writing on the shutter.
Line 1: "IMATION"
Line 2: "2HD"
Line 3: "2.0 MB"
And, as I pointed out, at the customary western high-density clock rate
of 500KHz and 300 RPM rotation--and 8 bit bytes, comes out to exactly
2,000,000 bytes.
Don't blame the manufacturer for getting less than you bargained for.
It's very clear that "2.0 MB" means 2 x 10**6 bytes.
It makes sense for the diskette manufacturer to use unformatted capacity;
after all, they have no control of the format parameters.
Using Si units is disappointing, but not surprising.
And, it probably wasn't even Wabash that started that.
BUT, the creator of the FORMAT would have no excuse for using unformatted
capacity (NeXT), nor miscalculating it (IBM)
4:27 p.m.
On 12/07/2014 02:35 PM, Fred Cisin wrote:
BUT, the creator of the FORMAT would have no excuse
for using unformatted
capacity (NeXT), nor miscalculating it (IBM)
Within the IBM literature, it would be interesting who decided to call
it "1.2MB"; 1,200K is perfectly legitimate, as is 360K, 320K and 720K.
For what it's worth, even under XP and Windows 7, FORMAT /A F:1440 and
/F:1200 work fine as format specifiers.
--Chuck
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