7 Jul
2006
7 Jul
'06
8:14 p.m.
Subject: Re: Intertec Super Brain question
From: Fred Cisin <cisin at xenosoft.com>
Date: Fri, 07 Jul 2006 19:14:51 -0700 (PDT)
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
On Fri, 7 Jul 2006, Chuck Guzis wrote:
1791 (they use inverted data and everything If memory serves).
Same as the 1793 only the data bus is inverted. They use the
inversion to make their files less readable. They were,
till everyone figured it out.
I've got a load of Super Brain CP/M diskettes
and find that for whatever
reason, the DAM (data address marks) seem to vary wildly on a disk-to-disk
sample.
What did the SB use for a diskette controller and why the varying DAM's
(sometimes it's just a single sector or group of sectors on a track)?
I've been told (but can't personally verify), that it's 179x They sure screwed up that format, didn't they?
The data is inverted relative to the address marks,
the index address mark is often too early for an NEC
(I often have to disable the index pulse to read them),
the head numbers on the second side are often wrong,
and I have no idea why the data address marks are flaky.
And they called DSDD 48tpi "quad" density, which meant
that when they came out with DSDD 96tpi, they called
that "Super Density", and abbreviated it "SD"!
(what is the next larger size of olives?)
Classic case of the 179x could so they did. Didn't make it a good
idea or even comforms to any standard.
The good news is that it usually doesn't object to a properly
formatted diskette, so it's often possible to format a stack
of diskettes; use the SB to copy the files to them, and then
bring those diskettes back to read.
I tried to talk to Intertec about their formats.
At NCC '83, some of their suits told me that they could
not imagine ANY possible reason to convert data between
disk formats, other than to steal their "proprietary"
software (CP/M?), and that they would file a lawsuit if
I included any SB formats in XenoCopy!
That night was the first time that I ever added formats
to XenoCopy in a hotel room.
They never kept that promise.
Yes there was the liklyhood that it meant more useful software
would be available for the 'brain. Likely took them longer than
a slow 8008 for that being a good thing to occur.
They used to have a sizable hobbyist following!
Never seen that many though they were nice to use.
Allison
--
Grumpy Ol' Fred cisin at xenosoft.com
9 Jul
9 Jul
4:09 a.m.
Allison wrote:
Seems that here in the UK they were the machine of choice for British Gas to
use back in the 80s - at least that's where all of ours seem to have come
from. We've even got some British Gas training course notes on both using and
servicing the machines [1], along with lists of common faults and what spares
their central workshop used to carry!
[1] The service training course notes mention the Northstar Horizon as a
useful piece of test equipment :-)
We've got something like 12 machines - three of each (Superbrain, Superbrain
II, Superbrain QD, and Computstar), then four hard disk units, plus a few of
what I gather are network boards for the Compustar systems.
Ultimately we'll keep a couple of systems I expect and re-house the rest, once
I know what's fixable and what isn't. I've got three machines plus a hard disk
unit in the car to restore over the next few days...
cheers
Jules
They used to
have a sizable hobbyist following!
Never seen that many though they were nice to use.
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