On 2020-03-07, Martin Gregorie  wrote:

> On Sat, 07 Mar 2020 10:31:41 +0000, The Natural Philosopher wrote:
>
>> On 07/03/2020 10:00, Martin Gregorie wrote:
>>
>>> On Sat, 07 Mar 2020 08:39:47 +0000, Jan Panteltje wrote:
>>>
>>>> In the eighties you had IBM drives of maybe it was 10GB? tha thad a
>>>> mechanical lever likething on the side, it ws connected to teh head
>>>> movement,
>>>> If the head positioning got stuck or something you could move that
>>>> lever and the thing would work again....
>>>> So, anyways, sorry about that.
>>>
>>> Wash your mouth out! Back in the '70s IBM was the Great Satan, with
>>> predatory salesmen and SEs, all in the dark suit, white shirt and blue
>>> tie company uniform and many brainwashed to the point of disbelieving
>>> that anybody other than IBM even made computers. Yes, I did meet, and
>>> worked with, a guy who had bought (gasp!) 3rd party disk drives and
>>> consequently had a posse of IBMers show up and harangue his management
>>> to try and get him fired.

I remember hearing those horror stories.  I worked with Univac gear -
that company was less organized but friendlier.

>>> Anyway - when I started work with ICL in the late 60s, our biggest
>>> disks were 8 MB. The drives were desk height, about 50cm X 80cm on top.
>>> They used removable cartridges with a stack of 10 recording surfaces,
>>> all 14" diameter. Spun at 2800 rpm and had an average access time of
>>> around 135 mS.

Sounds like an equivalent of the IBM 2311.

>>> By 1973 they'd grown to 60MB capacity and 20 recording surfaces, still
>>> using 14" platters, spun a bit faster (3600 rpm IIRC) and access time
>>> was down a little to under 100 mS. George 3 used a clever head movement
>>> scheduler that tripled the effective access rate.

Hmmm... double-density 2314?

>>> Biggest drive I ever saw back in the day was 400MB, still using 14"
>>> removable cartridges, but the number of recording surfaces had more
>>> than doubled.
>>>
>>> FWIW, I first saw a microcomputer in 1976/77 at The Computer Store in
>>> NYC at 5th and 35th, which sold SWTPC and Imsai systems, No disks of
>>> any sort - they weren't around much before the early late 70s when
>>> Shugart 5.25" floppies started to appear and then in the early 80s 5"
>>> hard drives with (gasp!) 5MB or even 10MB capacity started to appear.
>>
>> 8" floppies predated the 5 1/4" for some CP/M style machines
>
> Sure - seen 'em but never used them. IIRC an IBM invention - about the
> only time I can remember seeing them being used was watching an IBM
> engineer using one to load microcode into an S/38 during the run-up to
> the LSE Big Bang in the late 1980s.
>
>> My first computer had twin 5.25 but IIRC others used 8"
>
> Same here - my microcomputer experience started with writing assembler on
> a NorthStar box with a 6800 MPU. About the same time I briefly used BASIC
> on an Apple II at the BBC, where I was mainly writing COBOL on ICL 2900
> mainframes, to simulate how a contacts database for the Radio News people
> might work.
>
> My first computer was a 6809 box with 5.25" floppies, a whole 48KB of RAM
> and running the FLEX09 OS.

My first home computer was an 8080 CP/M box with 8-inch floppies.  I
refused to go to 5 1/4-inch floppies because they had no standard format,
making it a pain in the ass to change data with other users.  (This was
before the IBM Personal Computer imposed its own standard.)  Our club had
a Disk Maker, a floppy controller for the S-100 bus; it could handle over
400 different 5 1/4-inch disk formats.

> Mind you, the Beeb's pair of 2966 mainframes (respectively production and
> standby/development) only had 16MB of RAM each, but 'prod' supported
> around 400 users accessing 11 quite large interactive systems, written in
> death-defying COBOL with IDMSX databases.

16MB?  Luxury!  That was the theoretical maximum for the IBM 360.
I say theoretical because nobody could afford that much in real life.
Slightly later, into the 370 era, I recall reading in a trade rag
about how IBM rocked the industry by slashing the price of a megabyte
of memory from $75,000 to a mere $15,000.  Compare that to your
$1/gigabyte thumb drives...

> Tell that to the young people today and they'll never believe you ...

My first programming job, in 1970, was on a Univac 9300 - their answer
to the IBM 360/20.  It had 16K of memory.  Not gigabytes, or megabytes,
but kilobytes.  No disks, no tape - just cards.  You really learned how
to squeeze program code.  When we added disks (a pair of IBM 2311 clones),
we expanded the memory to a whopping 32K.  We wondered what we were
going to do with all that space.

Some of you folks might enjoy wandering over to alt.folklore.computers;
we talk about this stuff all the time there.

--
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