Dave Ahl was a big hit at VCF East 3.0 (2006), so we're bringing him
back this year. He will lecture on the second day (Sunday, Sept. 13) at
1 p.m. on the subject of "Blunders in Personal Computing."
http://www.vintage.org/2009/east/
OK, this is really geeky, but a DecWriter appears for
a few seconds in a short film by Neil Blomkamp, who
wrote and directed "District 9."
At www.spyfilms.com, click on Directors, Short Films,
Neil Blomkamp, and click on Tempbot. At about 1 minute,
15 seconds, Tempbot walks through a room with a DecWriter
in it. Where the heck did that come from!?
The other short on that page is "Alive in Joburg," the
short that District 9 was based on, worth watching
to see the germ of the idea.
Brian
Tony Duell wrote:
>>> What I would do next is grab a logic probe and the Unibus pinout (for the
>>> terminator slot) and see which grant(s) is being asserted at the
>>> terminator, if any. IIRC, the grants are active _high_, unlike most
>>> Unibus signals. Check the NPG, BG4, BG5, BG6 and BG7 signals at the M9302
>>> terminator
>>>
>>> -tony
>>>
>>>
>>>
>> Finally got a chance to do this; I hooked my logic analyzer to all the
>> grant signals on the last unibus slot and BG6 is held high constantly,
>>
>
> Rememebr a floating signal will appear as high. Also, if there's a device
> that uses BG6 and the BG6 is open between the CPU and that devices,
> thenBG6 In on said device will appear high, so the device logic wil
> faithfully pass on the grant and set BG6 Out high.
>
>
>> the others seem to be OK. I've confirmed that these are supposed to be
>> active high. Now to figure out what's raising the signal...
>>
>
> First check it's not stuck high at the processor end (this could be a
> fault with the rbitration logic or similar).
>
> Then I guess you do a half-split. Check it at a slot midway along the
> backplane, and move in the apropriate direction until you find what's
> causing it.
>
I disconnected 4-slot the UNIBUS backplane and just stuck the terminator
in A/B of slot 9 of the CPU backplane, and removed the SLU from the SPC
slot. I got the same readings there. I was fairly sure that it's not
the processor -- I make this supposition (and please don't get mad,
Tony :)) because I have a spare 11/40 set and they both exhibit the
exact same behavior when swapped around .
Then I double-checked the wiring for BG6 and the four wires are not
continuous, if I'm reading the wirelist correctly there's supposed to be
a connection from D07F2->F03R2->F03V2->D09M2. The connection between
F03R2 and F03V2 is nonexistent (no evidence of a wire at all). I built
a crude jumper (I need to get a wirewrap tool) and powered it up... and
it works! My God it works! Ha ha ah ahhah a hahahhaa!
Thanks for all the help, Tony (and everyone else too!)
Now to see if I can get the RL02 to boot something. :)
- Josh
> -tony
>
>
>
Hey all --
I'm one step closer to bringing my 11/40 back to life -- the front panel
is now responding and I can examine and deposit memory.
But the machine is only responsive without the Unibus terminator (an
M9302) installed. If it's installed, the front panel is basically hung
-- toggling "Start" causes a brief flurry of activity, but that's the
only thing that causes any response.
Without the terminator installed, the front panel more or less works, I
can examine and deposit memory, load the address register, etc... but I
can't get any toggled in code to run, obviously -- it traps to the bus
error vector at 00004.
(There's also an odd issue, which I doubt is related, but
Examining/Depositing does not correctly increment the address --
starting from 0, it's "0, 2, 6, 12, 16, 22, 26..." and if I start at 1
it's "1, 3, 7, 13, 17, 23, 27...")
I currently have the CPU boards + MMU option installed in the correct
order with a SLU card in the SPC slot, and an M981 connecting to a
4-slot Unibus backplane with a single 64K MOS memory card (M7891) in
slot 2 -- all other slots have grant continuity cards installed. The
Unibus terminator is installed in the last slot.
Any ideas?
Thanks as always,
Josh
Has anyone here done much programming of Motorola 68764s? I'm using
my usually reliable EZEP programmer, but the EPROMs don't show a good
erase (after an hour in the eraser, I can still see bytes with F7/F3
values). And trying to program 00 fails on the first byte after 25
pulses, showing 07 instead of 00.
I'm using Vcc of +6 and Vpp of +25. These EPROMs are supposedly NOS
and have date codes of 1982.
Any suggestions?
Thanks,
Chuck
Hi all --
Is there a good site/documentation covering the ins and outs of
Transputer hardware? (Or can anyone here help?) I'm interested in
building a small Transputer setup to play around with but I can't find a
good guide covering what's necessary and what hardware works with what, etc.
Of course, finding the hardware is probably going to be the major issue
here :). There are some TRAMs on ebay right now (item 220464801141) but
I need more hardware to actually interface it with a PC, etc... are
there any good sources for this hardware other than waiting for
something to show up on eBay?
Thanks as always,
Josh
Is there any serious interest here for DEC VT420s? I have a large pile
of them now, and am wondering if they are worth refurbing, or if I
should just scrap them out.
Also, I have access to a large number of 80 meg disk packs for the CDC
SMD drives. I do not really need them (I am more a 300 meg guy), but
is there interest in these?
--
Will
many types of course. Generally speaking do the materials used in pc's from
the 80s fall into a single category? Everything is injected into a mold for
sure, from largish cases to tiny keytops. Would all this qualify as
polystyrene? Whatever the case, what's a good solvent (not necessarily glue)
that's useful for repairing big cracks or splits, to tiny hairline cracks. I
say solvent, and some glues can fall into this category, because it makes
more sense to reinforce the materials from behind to effect a strong bond,
and for cosmetic sake meld the item from the front, to obscure the defect
itself.
Many surfaces are anything but smooth. Has anyone tried, given they were
successful in melding the surface, in reproducing the look of the surface
surrounding it? Smooth surfaces can be melded then touched up lightly
w/ultra fine emery cloth and some sort of lubricant I would guess. But the
rough textures are a different story.
I have no connection or knowledge of this site; I saw it posted as a
tweet from Ed_Dale from the Thirty Day Challenge (free IM course) since
apparently this is a site built using the 30DC lessons.
http://www.saldanah.com/applesale/
e.stiebler wrote:
>
> Hi all,
> so, after all this cleaning of contacts on old computers, is there
> anything really good to put on the contact surface to protect it ?
> Grease/Lubricants/etc. ?
>
> Thanks
>
The model railway people use ordinary light oil, extremely sparingly applied
(e.g. 1 drop for several metres of rail). Apparently the oil forms a very
thin film which protects against oxidation, and the wheels penetrate the
film, making contact despite the oil being an insulator. Obviously the
rails/contacts need to be cleaned first. Also the film is so thin that it
does not attract gunk.
