ISO: Corvus Concept parts

[Josh Dersch via cctalk]

I picked up a Corvus Concept CPU unit about a decade ago now, and I've 
yet to track down any other parts for it. Looking for keyboards, 
monitors, drives, peripherals software -- anything. If anyone's got any 
parts, please drop me a line.  Always wanted to see one run...


Thanks,

Josh

Re: RL01/RL02 emulator needed -- (was Many thanks to Glen's Vintage Computer Info)

[Paul Anderson via cctalk]

Hi Alan,

I just found an Emulex book that shows the SC02, SC04, and  SC12 as
supporting DEC RL drives. They show a model "L" for the RL drives. I'm
guessing different ROMS.

I'm sure DILOG and others companies made them, but I haven't found my DILOG
book yet.

I know people who have used them, but I cannot vouch for them.

Paul

On Wed, Apr 4, 2018 at 11:25 AM, Alan Frisbie via cctalk <
cctalk@classiccmp.org> wrote:

> "pe...@rittwage.com"  wrote:
>
> > You don't want to try to repair the controller? There are some custom
> > IC's on there (it appears) but is largely off-the-shelf TTL... I'm
> > sure someone on the list has a lot of experience with these and could
> > repair it or help.
>
> Indeed, I DO want to repair it, but that is a project for another day.
> Right now I need to solve the need for an RL02 emulator, which will let
> me quickly solve the current problem.
>
> Again, does anyone have any experience (good or bad) with any of the
> RL02 emulators our there?
>
> Thanks,
> Alan Frisbie
>

Re: Apple B CRT monitor popping and clicking

[Fred Cisin via cctalk]

They are colour. In this context, B means "blue and white", as in the
G3 tower (and monitor) colour scheme. Pinstripy if I recall correctly.



On Wed, 4 Apr 2018, Jules Richardson via cctalk wrote:
I never thought I'd see B in the context of displays mean anything other 
than black & white, but of course in a discussion about Apple hardware, 
anything is possible :-)


It is sometimes surprising where terminology becomes ambiguous.

At the college, with a few dozen 5150s, we used CGA cards with cheap B 
composite monitors, including some that were marketed for CCTV.  THAT 
permitted us to afford substantially more machines than either IBM CGA 
color monitors OR IBM "monochrome" card and monitor.  That was before the 
aftermarket reached full saturation.


But, when shopping for cheap composite monitors, when you asked about B 
monitors, you would often get told that they had none.  because what they 
had were green or amber phosphor.
If you asked for monochrome, then they started in with monitors compatible 
with the IBM MDP/MDA or Hercules cards.
What is the minimum phrase that will unambiguously (or minimum ambiguity) 
specify B (of any color of phosphor) with composite input?


YES, the IBM monochrome monitor, or later after-market with Hercules 
compatible cards, IS a much better image.  But, for running a text editor 
and a compiler, the choice was between 15 computers with CGA color, 20 
with IBM monochrome, or 30 with CGA and cheap composite monitor. Our 
priority was to try to have almost enough machines for the number of 
students.  And contrary to demands from SOME instructors, you do NOT need 
color to learn to use WordPervert, Lotus, or programming tools.  Later, 
when we were finally using generic 386SX machines, we had an instructor 
who was teaching a course on Unix, who insisted that all the machines had 
to have VGA.  Again - enough minimal machines for everybody, or half 
enough machines with fancy preferred hardware?



--
Grumpy Ol' Fred ci...@xenosoft.com

Re: Apple B CRT monitor popping and clicking

[Jules Richardson via cctalk]

On 04/03/2018 08:08 PM, Toby Thain via cctalk wrote:

They are colour. In this context, B means "blue and white", as in the
G3 tower (and monitor) colour scheme. Pinstripy if I recall correctly.


I never thought I'd see B in the context of displays mean anything other 
than black & white, but of course in a discussion about Apple hardware, 
anything is possible :-)

DEC DEREP repeater PSU

[Adrian Graham via cctalk]

Hi folks,

Has anyone ever replaced the PSU in a DEREP with a more modern equivalent? The 
PSU is an ASTEC but as usual doesn’t have any markings for ratings or pinouts. 
I found the tech ref online but for PSU problems it just says ‘replace’ as I’d 
expect. Test LEDs on the unit itself (and the fuses) show +5 and +12 at 2A.

This one suffered a bad heat-based death at some point after the fan seized…

Cheers,

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs 

w: www.binarydinosaurs.co.uk 

Re: RL01/RL02 emulator needed -- (was Many thanks to Glen's Vintage Computer Info)

[Alan Frisbie via cctalk]

"pe...@rittwage.com"  wrote:

> You don't want to try to repair the controller? There are some custom
> IC's on there (it appears) but is largely off-the-shelf TTL... I'm
> sure someone on the list has a lot of experience with these and could
> repair it or help.

Indeed, I DO want to repair it, but that is a project for another day.
Right now I need to solve the need for an RL02 emulator, which will let
me quickly solve the current problem.

Again, does anyone have any experience (good or bad) with any of the
RL02 emulators our there?

Thanks,
Alan Frisbie

Re: DEC 3000 (alpha) faultfinding

[Peter Coghlan via cctalk]

>
> > I ran the various tests provided by the different jumper settings on my 
> > second
> > 3000 600 and I found that the memTest (no-cache) LongWord Memory Test 
> > (position
> > 5, J3) failed as well as the tests involving the cache.  In an attempt to 
> > find
> > which memory was failing, I swapped around the memory risers.  Bizarrely, 
> > the
> > (no-cache) failures went away completely when I swapped around the front two
> > risers.  The failures returned when I swapped them back.  This is very odd 
> > as
> > the two risers appear to be identical and seem to be populated with 
> > identical
> > SIMMs.
>
>  Have you tried cleaning the pins?
>
>  The riser connectors are the same style DECstation 5000/200 MS02 memory 
> modules use and I had cases of ECC errors appearing with those which went 
> away once thorougly cleaned with IPA.  Lone reseating didn't help.
>

I did some more experimentation and I found that the failures consistently
occurred when a particular riser was installed in one of the rear facing
riser slots and consistently did not arise when that riser was installed in
one of the front facing slots.  I also noticed that the mini console
consistently reported:

memSize 00c0.00c0

when the the failures occurred and consistently reported:

memSize 00a0.00a0

when they did not occur.  The failures could not be provoked when I swapped
the suspect riser with one from the other machine.  Further swapping of
individual simms on the suspect riser narrowed down the cause of the problem
to one particular simm on that riser.  Unfortunately, after eliminating the
faulty simm, the cache faults and occasional machine checks were still present.

Going back to the other 3000 600 that does not experience machine checks and
putting back it's full set of good memory risers, I am left with just the
cache issues to deal with.  Unlike the Alphaserver 1000A, there does not
appear to be any obvious way of disabling the cache.  It appears it could be
done if I could write to the ABOX_CTL and BIU_CTL registers.  Unfortunately,
while this could probably be done with the "dc" mini console command on some
other processor models, this command does not seem to be implemented on the
3000.

Regards,
Peter Coghlan

>   Maciej
>

Re: DEC 3000 (alpha) faultfinding

[Maciej W. Rozycki via cctalk]

On Sat, 31 Mar 2018, Peter Coghlan via cctalk wrote:

> I ran the various tests provided by the different jumper settings on my second
> 3000 600 and I found that the memTest (no-cache) LongWord Memory Test 
> (position
> 5, J3) failed as well as the tests involving the cache.  In an attempt to find
> which memory was failing, I swapped around the memory risers.  Bizarrely, the
> (no-cache) failures went away completely when I swapped around the front two
> risers.  The failures returned when I swapped them back.  This is very odd as
> the two risers appear to be identical and seem to be populated with identical
> SIMMs.

 Have you tried cleaning the pins?

 The riser connectors are the same style DECstation 5000/200 MS02 memory 
modules use and I had cases of ECC errors appearing with those which went 
away once thorougly cleaned with IPA.  Lone reseating didn't help.

  Maciej