Hi
As much as I would like to see something along these lines.
It would be best to sort out the funding first.
Perhaps a small group of interested parties could meet to see if such an
event is feasible in the UK.
Rod Smallwood
-----Original Message-----
From: cctech-bounces at classiccmp.org
[mailto:cctech-bounces at classiccmp.org] On Behalf Of Andrew Burton
Sent: 02 August 2007 23:16
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: UK VCF?
Roger Holmes <roger.holmes at microspot.co.uk> wrote:> First a simple
question, how many readers of > this list are in the UK?
I am one of (hopefully) many :)
> If Bletchley Park might be able to do a VCF in > two or three years
> time, maybe we could do something much simpler in the mean time,
> without using the VCF name. Just a get together of anyone in the UK
> with an interest in old computers and hopefully > a few who would want
> to exhibit theirs. Who would be interested and > about how much space,
> if any would they want?
Not much. Just enough to have a table for my laptop & opened up Amiga. I
could bring a few issues of 80 Microcomputing aswell, which would be the
ones I have duplicates of. The duplicates aren't in particularly good
condition so it doesn't matter too much if they were to get accidentally
damaged :) All the other issues of 80 Microcomputing I have are pretty
much in mint condition and I wouldn't risk bringing to the event (is
that bad? Would anyone else feel the same way?).
> I guess we would need to double that up to allow for aisles etc. Then
> we'll know the size of venues to look for. By the way, I was really
> thrown by the mention of the planet Venus, it took me a while to work
> out it was a typo for venues :-)
>
> Then there's the question of vehicle parking.
> How many and are we
> talking only cars and small vans or big vans and articulated lorries?
I'd just bring my car.
> Roger,
> who is planning a 1300 sq ft extension to his computer room, and who
> lives on a farm in Kent. Probably too small and > not central enough,
> but who knows.
Regards,
Andrew B
aliensrcooluk at yahoo.co.uk
Hi,
> What is wrong with C?! :(
Don't get me started.... ;-)
> Yes it is not assembly, but it is also much closer to the
>hardware then most of the other structured programming languages
>out there!
I've always regarded "C" as more of a "high level macro assembler", I
personally don't regard it as a high level language as such - sort of a
halfway house.
Now, if you understand how C "works" (read K&R a few times as a start) and
the intimate details of your target hardware then you can do a passable job.
The problem is, most programmers nowadays simply don't have that level of
knowledge, which inevitably leads to large, slow, buggy firmware which is
nigh on impossible to fully debug.
And then there's the issue of readibility. I don't care what anyone says, I
find assembly language listings VASTLY easier to understand than someone
elses' "C" code no matter how well commented/documented (even when I've
never encountered that particular processor before).
I'll give you a personal example. I was once tasked with converting a real
time OS from Z8 assembly language (yes, Z8) to V50 (x86) assembly language;
we're talking a lot of code here, the assembled code filled almost an entire
32K EPROM.
Took me about three and a half weeks, at the end of which I had a well
structured, fully documented and FULLY DEBUGGED (I took a LOT of pride in
never releasing code which was less than 100%) product which was cleared for
production.
Unknown to me at the time, initially at least, my boss also tasked our "C"
programmer to do the same job. He did the conversion in about two
weeks....and then spent the next TWO MONTHS trying (and failing) to track
down the bugs in his code, about a third of which were caused by compiler
bugs rather than something he'd done wrong.
I was eventually brought in to help him, at which point I learnt rather a
lot about how bloated and inefficient the output from "C" compilers can be.
Needless to say, it was impossible for us to fully debug his code (or fit it
into a 32K EPROM for that matter) and so it was dropped in favour of mine.
"C" certainly has it's uses (I'm sure), but in my opinion, embedded
systems/device drivers isn't one of them....
TTFN - Pete.
> I recall a conversation with a fellow at Xerox R&D on Coyote Hill
> Road (not PARC) around 1983 or so. He remarked that much of the
> Xerox document management code was in 'B' and not C.
Unlikely. 'B' was a BCPL derivative which predated 'C' at Bell Labs.
BCPL was used at PARC as the basic high level language for the Alto.
During this same time period, a strongly typed language called Mesa
was developed, which was used on the Alto, and later on the machines
which evolved into the Xerox Star. Variations of Mesa were the primary
Xerox development languages up through Globalview, which caused Xerox
huge problems with hiring programmers, since no one outside of this
world had any experience with the language. They eventually developed
a Mesa to C translator called Memosa.
>
>Subject: Re: PERQ T2
> From: ard at p850ug1.demon.co.uk (Tony Duell)
> Date: Thu, 02 Aug 2007 19:54:44 +0100 (BST)
> To: cctalk at classiccmp.org
>
>>
>> Hi Tony,
>>
>> Thanks for the reply.
>>
>> The drive is a Micropolis 1303, and I think it has
>> failed. The
>> drive does spin down after a minute or so.
>
>You know, it's really hard debuggin a machine when you're not told all
>the symptoms :-)
>
>More seriously, this does sound like the standard Micropolis 1300-series
>problem, when that rubber bumper goes sticky and prevents head movelemt.
>The bad news is that all Micropolis 1300s (and their ESDI equivalent?)
>suffer from it, or at least if they don't they will soon.
>
>Finding a replacement 1300-seires is probably not the wisest thing to do,
>therefore.
>
>I've never tried it, but I have heard that people have had some success
>in openign up the HDA *yes, outside a clean room), removing the bumper,
>shutting the whole thing up and using the drive as normal. How long it'll
>keep working is anohter matter.
I've done it three times and two are still running over 8 years
and many thousands of hours later.
I'ts been done by others.
Allison
>>
>> I noticed the PERQ manuals do state that the hard disk
>> must
>> be able to perform a "locate disk heads" operation,
>> even
>> for a floppy boot - which I assume means find track 0.
>
>I beleive the hard disk must og 'Ready' Quite what that means I will have
>to check -- the boot ROMs check for a particular state in one bit of a
>particluar port. I candig out the EIO and DIB schematics to find out just
>waht that means if you like.
>
>> Hence
>> I'm unable to boot from floppy.
>>
>> I will check the signal levels just to be sure.
>>
>> Wondering where to go from here. I'm guessing I could
>> buy a
>> replacement 1303 drive - but they are not cheap (hence
>> my
>> other posting) just to try and see.
>
>Any reason not tu use some other ST412-interfaced drive? The PERQ _can_
>use it.
>
>-tony
I might be interested in these if you still have them
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Hi Tony,
I did try some other drives, namely some MFM drives
I had to hand from a PDP 11. These were ST-412
drives.
I simply connected the existing PERQ controller to the
new drive, hoping the hard disk would show ready, but
no joy.
The drive didnt even show a flicker on the LED.
The drives were all known working, and boot fine on a
11/23. I didnt change any jumpers as the drives were
the only drive in the PDP 11's.
Could this mean a fault EIO card?
I've examined the board carefully under a maginfier
for
track breaks, dry joints, and damage. The edge
connectors
were cleaned and all IC's have been carefully
re-seated.
Ian.
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Hi Tony,
Thanks for the reply.
The drive is a Micropolis 1303, and I think it has
failed. The
drive does spin down after a minute or so.
I noticed the PERQ manuals do state that the hard disk
must
be able to perform a "locate disk heads" operation,
even
for a floppy boot - which I assume means find track 0.
Hence
I'm unable to boot from floppy.
I will check the signal levels just to be sure.
Wondering where to go from here. I'm guessing I could
buy a
replacement 1303 drive - but they are not cheap (hence
my
other posting) just to try and see.
Ian.
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Brent Hilpert wrote:
> Around 1980 I was programming in Z (dev'd at U of Waterloo IIRC, Thoth/Verex
> OS), another descendant of B/BCPL and so a sibling of C
Are there still copies of Z or the operating systems around that you know of?
I asked Dave Cheriton about this a few years ago, and he didn't have a copy.
On the chance that someone might know someone from HP Colorado Springs..
Is there any documenation around on the operating systems or internal
workings of the 16500A or B logic analyzers? The 500B is a pretty sophisticated
device, but of course there is no useful docs in the service manual on how
the hardware or software actually works.
