3 Jun
2004
3 Jun
'04
3:08 a.m.
just to keep terminology correct... the 8" inch came as single
or double density - high density entered the marketplace with
the introduction of the IBM AT in 1985 that had 5 1/4" high density
disk drives.
Maybe internationally things were referred to as low and high
density, but not to my recollection in the States or in any drive
datasheets I have seen.
best regards, Steve Thatcher
3 Jun
3 Jun
3:28 a.m.
Subject: RE: Re: 8" hard sectored floppies
just to keep terminology correct... the 8" inch came as single
or double density - high density entered the marketplace with
the introduction of the IBM AT in 1985 that had 5 1/4" high density
disk drives.
You are right, I'm sorry. I keep making the same error time and time again.
Probably old-age related...
Thanks
Nico
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3:03 p.m.
New subject: What is bigger than a "super Jumbo Colossal" olive? (was: 8" hard sectored floppies
On Thu, 3 Jun 2004, wrote:
just to keep terminology correct... the 8" inch
came as single
or double density - high density entered the marketplace with
the introduction of the IBM AT in 1985 that had 5 1/4" high density
disk drives.
Maybe internationally things were referred to as low and high
density, but not to my recollection in the States or in any drive
datasheets I have seen.
Most of that "terminology" was actually marketing HYPE.
"Single Density" never existed until AFTER "Double Density"!
(Likewise, if you search old newspaper databases, you will
find that there was NOTHING called "World War I" until AFTER
discussion started about "World War II", and there was no such
thing as a "TRS-80 Model I" (it was simply called "TRS-80")
until the model II and III were started.)
Instead, we had "FM" ("Frequency Modulated") encoding. Then
MFM ("Modified Frequency Modulation") was developed. The
MARKETING people (a group of mindless jerks who'll be first
against the wall when the revolution comes!) came up with the
apellation of "DD/"DOUBLE DENSITY". THEN they had to
differentiate the "old" system, so they renamed that
"SD"/"SINGLE DENSITY".
Some data communication engineers would argue that "Single
Density" is WRONG, since it is really "HALF density",
with one bit of data for every two flux transitions.
And "Double Density" is really only about 3/4 density.
Then, for DSDD (double sided, double density), SOME
mindless jerk marketing people (such as at Superbrain/Intertec)
who didn't have a clue about the difference between
capacity and density, decided to call that "QD"/"Quad Density"
When number of tracks was doubled, the mindless jerk
marketing people called that "QD"/"Quad Density". Except
for the mindless jerk marketing people at Superbrain/Intertec;
they had already used up the name "QD"/"Quad Density", so
they needed a bigger superlative, and called it "SD"/"Super Density"!
The mere concept that "SD" already meant "Single Density"
was lost on newcomers who don't acknowledge anything that
happened before THEY got into it (like the MICROS~1 mindless jerks
who don't understand that a "COM file" is a memory image
executable program))
But, then, when density was finally increased, "quad density"
and "super density" were already used up as names, so the
mindless jerks called it "HD"/"High Density".
"HD"/"High Density"
is MFM at 500K bits per second data transfer rate on a 360
RPM drive. (Which is exactly what 8" DD was)
"Low density" has NEVER been used as a name - what
marketing person would saddle their system with THAT??
--
Grumpy Ol' Fred cisin(a)xenosoft.com
4 Jun
4 Jun
11:33 a.m.
New subject: What is bigger than a "super Jumbo Colossal" olive? (was: 8" hard sectored floppies
On Thu, 2004-06-03 at 17:03, Fred Cisin wrote:
But, then, when density was finally increased,
"quad density"
and "super density" were already used up as names, so the
mindless jerks called it "HD"/"High Density".
"HD"/"High Density"
is MFM at 500K bits per second data transfer rate on a 360
RPM drive. (Which is exactly what 8" DD was)
Fred, you should stop remembering these things, it's bad for you.
PS: To this day I can't remember which is which, EXTENDED or EXPANDED
memory, thankfully there's no need to any more.
12:16 p.m.
New subject: What is bigger than a "super Jumbo Colossal" olive? (was: 8" hard sectored floppies
On Friday 04 June 2004 15:33, Tom Jennings wrote:
PS: To this day I can't remember which is which,
EXTENDED or EXPANDED
memory, thankfully there's no need to any more.
It's quite simple, acutally. : )
Extended memory _extends_ the address space available (eg more than 20
bit address space). Expaneded memory _expands_ the amount of memory
you can have in the same amount of address space (aka bank switching).
Pat
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Purdue University ITAP/RCS --- http://www.itap.purdue.edu/rcs/
The Computer Refuge --- http://computer-refuge.org
3:05 p.m.
New subject: What is bigger than a "super Jumbo Colossal" olive? (was: 8" hard sectored floppies
On Fri, 2004-06-04 at 14:16, Patrick Finnegan wrote:
On Friday 04 June 2004 15:33, Tom Jennings wrote:
You're kidding, right?!
I'm getting a headache now, please stop hurting me!
It's like the left-hand rule. I remember the rule, only I forgot what
it's for. Or was it the right-hand rule... current, flux, well it's one
or the other, eh?
PS: To this day I can't remember which is
which, EXTENDED or EXPANDED
memory, thankfully there's no need to any more.
It's quite simple, acutally. : )
Extended memory _extends_ the address space available (eg more than 20
bit address space). Expaneded memory _expands_ the amount of memory
you can have in the same amount of address space (aka bank switching).
3:55 p.m.
New subject: What is bigger than a "super Jumbo Colossal" olive? (was: 8" hard sectored floppies
On Friday 04 June 2004 19:05, Tom Jennings wrote:
On Fri, 2004-06-04 at 14:16, Patrick Finnegan wrote:
Heh sorry. I wasn't joking...
Extended memory _extends_ the address space
available (eg more than
20 bit address space). Expaneded memory _expands_ the amount of
memory you can have in the same amount of address space (aka bank
switching).
You're kidding, right?!
I'm getting a headache now, please stop hurting me! It's like the left-hand rule. I remember the rule,
only I forgot what
it's for. Or was it the right-hand rule... current, flux, well it's
one or the other, eh?
Just like "all the world's a VAX," "everyone is right handed."
Right
hand rule, and it relates current and flux lines. Since you
(hopefully) know that current usually doesn't flow in loops around
wires, it should be obvious what it relates. : )
Pat
--
Purdue University ITAP/RCS --- http://www.itap.purdue.edu/rcs/
The Computer Refuge --- http://computer-refuge.org
6 Jun
6 Jun
3:03 p.m.
New subject: What is bigger than a "super Jumbo Colossal" olive? (was: 8"hard sectored floppies
Which left-hand rule are we considering ?
:^)
Geoff.
----- Original Message -----
From: "Patrick Finnegan" <pat(a)computer-refuge.org>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk(a)classiccmp.org>
Sent: Saturday, June 05, 2004 1:55 AM
Subject: Re: What is bigger than a "super Jumbo Colossal" olive? (was:
8"hard sectored floppies
It's like
the left-hand rule. I remember the rule, only I forgot what
it's for.Pat
--
Purdue University ITAP/RCS --- http://www.itap.purdue.edu/rcs/
The Computer Refuge --- http://computer-refuge.org
4:18 p.m.
New subject: What is bigger than a "super Jumbo Colossal" olive? (was: 8"hard sectored floppies
On Sunday 06 June 2004 19:03, Geoffrey Thomas wrote:
Which left-hand rule are we considering ?
The rule that says that no engineer or physicist is left-handed. :)
Careful on your quoting, I *definately* didn't say what your message
makes it appear I did...
----- Original Message -----
From: "Patrick Finnegan" <pat(a)computer-refuge.org>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk(a)classiccmp.org>
Sent: Saturday, June 05, 2004 1:55 AM
Subject: Re: What is bigger than a "super Jumbo Colossal" olive?
(was: 8"hard sectored floppies
> > It's like the left-hand rule. I remember the rule, only I forgot
> > what it's for.Pat
>
> --
> Purdue University ITAP/RCS ---
> http://www.itap.purdue.edu/rcs/ The Computer Refuge
> --- http://computer-refuge.org
--
Purdue University ITAP/RCS --- http://www.itap.purdue.edu/rcs/
The Computer Refuge --- http://computer-refuge.org
4 Jun
4 Jun
12:54 p.m.
New subject: What is bigger than a "super Jumbo Colossal" olive? (was: 8" hard sectored floppies
> mindless jerks called it
"HD"/"High Density". "HD"/"High Density"
> is MFM at 500K bits per second data transfer rate on a 360
> RPM drive. (Which is exactly what 8" DD was)
On Fri, 4 Jun 2004, Tom Jennings wrote:
Fred, you should stop remembering these things,
it's bad for you.
PS: To this day I can't remember which is which, EXTENDED or EXPANDED
memory, thankfully there's no need to any more.
OK, here's today's dosage of useless obsolete trivia:
"EMS"/"Expanded" memory
is simply bank switching. Even with only 20 bits of address,
almost unlimited memory could be used by switching a little p
iece at a time into a gap inthe memory map. Some of the first
commercial products werethe JRAM boards from Talltree Systems.
Henderson approached me at the West Coast Computer Faire,
and asked if I had written any software that used a lot of memory.
I thought that he was looking for programmers for a contract job.
NO! He was looking for software that NEEDED RAM, in order
to peddle RAM cards. But almost nothing used THAT much RAM.
So, he developed a laser printer interface (JLASER for Canon CX)
that did all of the rasterizing, etc. in the host computer,
and THAT took some RAM!
Then Lotus, Intel, and Microsoft (excluding Talltree!) developed
the "LIM EMS" "Lotus Intel Microsoft Expanded Memory Specification"
"XMS"/"Extended" memory
is simply normal memory accessed by having more than 20 bits
of address bus, and therefore not usable in the Intel Segment:Offset
"REAL MODE" memory addressing system. 286 and 386SX supported
24 bits of address (16M), and a real 386 could theoretically be
made with 32 bits (4G)
"LIMSIM":
It was possible in software to make extended memory behave
like expanded memory, so that REAL MODE software could
still make limited use of extended RAM (for RAMDISK, print spooler, etc.)
"HIMEM":
People noticed that with 21 bits of physical addressing
capability, "REAL MODE" Segment:Offset could overflow to access
almost 64K of additional(extended) memory. Then MICROS~1
"invented" it, and declared that to be THE ANSWER (tm?)
to all "RAM-CRAM" problems, and started PUSHING HIMEM.SYS.
EVERYTHING from MICROS~1 would install it. If you got a
MICROS~1 T shirt, it would try to install it.
Windoze 3.0 was the last version that could run or be installed
without the presence of Extended memory, and therefore was the
last version to be runnable on PC or XT.
1:49 p.m.
New subject: What is bigger than a "super Jumbo Colossal" olive?
Fred Cisin wrote:
"EMS"/"Expanded" memory
is simply bank switching.
...
So, he developed a laser printer interface (JLASER for
Canon CX)
that did all of the rasterizing, etc. in the host computer,
and THAT took some RAM!
I used a JLASER card for my first explorations of PostScript, way
back in 1987. I worked for a small software house called London
Software Studio, and we wrote presentation graphics software. One
of our plans was to add a postscript hard-copy option, so that
users could make high-quality printouts and OHP transparencies.
I still have the PostScript code that I wrote on that thing, using
a Victor 286 machine as the host.
--
John Honniball
coredump(a)gifford.co.uk
2:05 p.m.
New subject: What is bigger than a "super Jumbo Colossal" olive? (was: 8"
PS: To this day I can't remember which is which,
EXTENDED or EXPANDED
memory, thankfully there's no need to any more.
Oh that one's easy... exPanded memory is the Paged one.
And classic computer people surely do have to remember this (heck, I have
expanded memory on my HP150...)
-tony
7 Jun
7 Jun
12:54 p.m.
New subject: What is bigger than a "super Jumbo Colossal" olive? (was: 8"
On Fri, 2004-06-04 at 16:05, Tony Duell wrote:
... and you're the only one to address the original point, the
obfuscatory marketese that blurred two distinctly different memory
features into one meaningless blob of verbiage.
PS: To this
day I can't remember which is which, EXTENDED or EXPANDED
memory, thankfully there's no need to any more.
Oh that one's easy... exPanded memory is the Paged one. And classic computer people surely do have to remember
this (heck, I have
expanded memory on my HP150...)
Not me! I've no interest in the Beige Era!
7422
days inactive
7426
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12 comments
8 participants
participants (8)
-
ard＠p850ug1.demon.co.uk -
cisin＠xenosoft.com -
coredump＠gifford.co.uk -
geoffreythomas＠onetel.net.uk -
melamy＠earthlink.net -
nico＠farumdata.dk -
pat＠computer-refuge.org -
tomj＠wps.com