Just when I thought eBay couldn't get much stupider...
I went out to see if I could find a current going price for
PDP-11 Pedestal Boxes as I have a couple I would like to
cull from my collection. I came upon this:
DEC PDP 11/23 - BC needs Power Supply Repair, NO cards, Vintage DEC History
$900.00
If it has no cards, what makes it a PDP-11/23 other than the paint
on the front cover? Dead PSU? Looks like a $900 backplane to me.
And that is making the assumption that the backplane is actually
usable. :-)
bill
The table request form for VCF Midwest 20 will open at 19:00 CDT next
Friday, June 27th. Read the mailing list announcement here:
https://list.vcfmw.org/w/TagW1e4K9x4Rl8wpSnorrA
(and join the mailing list, too, if you haven't!)
-jt
Bill Atkinson, a true early microcomputer pioneer, ca. 1984+, brought
drawing on a computer screen and linking to external files a reality. He
will be missed.
Murray--
I've been digging through a few shelves of backplanes looking for a
specific one for a listmember. Along with the DD11-CK and DKs, I found a
RK611 and RH11. I probably have the boards for both. Any interest?
Also found a few DDV11-D which I think is a 6x9 hex qbus backplane, but
it's been a while.
If you need any backplanes (11/84, 11/44) or options (DR11-B, etc) now is
the time! Also a lot of core memory and backplanes.
Please contact me off list.
Thanks, Paul
Hi all,
by surprise I got a Tadpole Sparcbook 2 some time ago.
Sadly there seems to be almost no documentation available in the net for
a Sparcbook 2, neither a technical/service nor a user manual, only for
Sparcbook 1 and later models.
I do have the following issues:
- the battery pack is missing.
I found two ressources, e.g. the CHM - but none does have any infos
about the battery pack
- The external power connector requieres 18V - no problem
- After connecting the fitting power the Sparcbook does power up, the
display is lit and the unit is trying to boot from the internat SCSI
disc. Nevertheless the boot process is failing this is a good sign.
- after trying to reboot the unit will be almost dead. While pressing
the power on button the LEDs on the left upper side of the display will
be lit shortly, but nothing else will happen.
- trying to reboot an power on the same as above will happen
If I'll keep the unit several weeks/months unpowered the unit will power
up again - but of course will be stuck again while trying to boot from
disk and the same semidead issues as noted above.
I'm suspecting the TOD chip/battery is deads or are there any other
sugegstions?
Up to today I didn't have a look inside of the unit ...
Does any have the manuals hidden in theirs shelves?
Best
Andreas
In addition to everything already cited, he developed what is still my
favorite dithering algorithm. Atkinson dither was probably optimized
more for speed than anything, but I've always loved the look of it, and
have even implemented it myself for that reason. R.I.P., sir.
Tadpole were in Cambridge, weren't they ?
https://www.computinghistory.org.uk/ have collected a fair bit of
Cambridge history. I haven't found them very willing to search their
archives but there may be individuals who have more time available, or
they may have a resource problem in putting information online.
On Fri, Jun 6, 2025 at 8:28 AM erik--- via cctalk <cctalk(a)classiccmp.org> wrote:
>
>
>
> Hi Andreas,
>
> great that there are still some people looking into the
> old SPARCbooks from Tadpole. I have got a 3GX up and running.
>
> > Sadly there seems to be almost no documentation available
> > in the net for a Sparcbook 2
>
> Yeah, that is really sad. Also do not have got any information!
> Just to report from my work on the 3 series ones (which are
> probably not to different from the earlier ones):
>
> Mine works without battery pack, so there is some intelligence
> in the battery pack (for power management), but using a power
> supply it is working even without that pack!
>
> > - after trying to reboot the unit will be almost dead.
> > While pressing the power on button the LEDs on the left
> > upper side of the display will
> > be lit shortly, but nothing else will happen.
>
> Hmm, that sounds strange and I never observed this due to
> lost NVram values. But what I observed is the yellow/orange
> Tantalum caps going bad in the small power supply piggy back
> PCB inside the unit. A short prevents the notebook from
> working (and sometimes even some inductors release smoke and
> completely destroyong the PCB depending on which cap went
> short).
> After a longer time powered off, the faulty cap can recover
> explaining your observation. Fortunately I had some spare
> PCBs and replaced all caps in my live one which works nicely
> now...
>
> Good luck,
>
> Erik.
>
