VAXen and minimal memory (was Re: The PDP11/04 has landed..)
Jerome H. Fine
jhfinedp3k at compsys.to
Thu Feb 11 10:56:03 CST 2016
>Jon Elson wrote:
> >On 02/11/2016 08:56 AM, Mark Wickens wrote:
>> It's good to hear that the VAX was a cost-effective solution - there are
>> too many stories about how expensive DEC gear was, but I imagine they
>> primarily came after PCs started dropping in price.
> We paid somewhere between 200 and 250K for our first 11/780. We had
> an RM05 and a TU77, and 256 KB of memory. It was a pretty basic
> system, but ran rings around the campus 360/65 system. We also had a
> pair of 370/145's that were an expensive joke. (The 360/65 ran rings
> around BOTH of them. They ran time sharing on them, limited to 4
> users/machine. We often had 8+ users plus batch jobs running on our
Any idea about the date of when VMS could do that with a VAX?
I don't remember how expensive a Cyber 3300 was back in 1967, but I
worked at Northern Electric in Ottawa at the time.
The standard operating system was being used (I certainly can't remember
the actual name) and there were CDC (washing machine sized) disk drives
with those removable platters.
The IT department produced software which was able to support many users
editing files via CRT terminals. I can't remember the maximum number, but
I would estimate that it was at least a dozen. There were also a number of
commands, one of which allowed a file to be submitted as a batch job. The
batch job queue was able to run ONE job at a time. There might have been
a high priority queue for very short jobs.
Every night, the system backed up all the hard disk files to tape.
At one point, the size of the file directory was increased from about
to about 6000 files. In addition, the search algorithm changed from linear
(start to when the file was found) to a hash value based on the name of the
file - normally the first file access found the file label block number.
The reason for this reply is to document that there were already such
systems available with very innovative software solutions as far back
as the 1970s. About a year later in 1968, a utility opened in Toronto,
MAGCC (Multiple Access General Computer Corporation if I remember
correctly) which supported the identical software using a Cyber 3500.
Thus the software concept had started to spread, They used dial-up
modems, probably around 300 baud. I don't remember dial-up
modems being capable of 9600 baud until a decade later.
I also can't remember what a Cyber 3300 cost back in 1967, but I would
suggest that the cost per user was probably similar to what VMS on a VAX
supported, but MANY years later than 1967 to 1968.
If anyone is really interested. it might be possible to search for the
However, Northern Electric is VERY long gone now!
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