12 May
2016
12 May
'16
7:58 p.m.
I just got the new boards:
https://www.flickr.com/photos/22368471 at N04/albums/72157668325096875
Differences of new version:
* bezel is black with white legends
* legend font is a bit larger and heavier
* legends are above switches
* switch PCB wiring errors fixed
* right angle header
* plastic caps installed on all toggles
I assembled the new one with C&K switches that are more readily
available (e.g., from Digi-Key and Mouser), but I don't like them as
much. Originally I used switches with a V-bracket which makes
alignment and assembly easier, and they have a uniform threaded
bushing height. The more common toggle switches have a longer threaded
bushing. This can be seen by comparing the edge-on views; for the more
common switches without the V-bracket, the red switch body is seen.
I'm soliciting input as to whether the switch legends should be
changed from the vector font to a "real" font, and if so, what font
and size is desired.
12 May
12 May
8:38 p.m.
On 5/12/2016 9:58 PM, Eric Smith wrote:
I just got the new boards:
https://www.flickr.com/photos/22368471 at N04/albums/72157668325096875
Differences of new version:
* bezel is black with white legends
* legend font is a bit larger and heavier
* legends are above switches
* switch PCB wiring errors fixed
* right angle header
* plastic caps installed on all toggles
I assembled the new one with C&K switches that are more readily
available (e.g., from Digi-Key and Mouser), but I don't like them as
much. Originally I used switches with a V-bracket which makes
alignment and assembly easier, and they have a uniform threaded
bushing height. The more common toggle switches have a longer threaded
bushing. This can be seen by comparing the edge-on views; for the more
common switches without the V-bracket, the red switch body is seen.
I'm soliciting input as to whether the switch legends should be
changed from the vector font to a "real" font, and if so, what font
and size is desired.
Not sure if I am completely understanding the concerns with
the
switches, but:
* I would install the switches and run the top nut out to the very
end, then back the inside nut up to it on the other side of the bazel
* Once all switches are installed, then insert the board and solder.
Of course, this fails if the bezel has to be only a certain height above
the PCB, but perhaps that is not critical and thus my idea has a chance
of working.
I'm not your market segment, but I think a better font would be
welcome. I looked online for a bit, but saw no specific font that would
have historical value, except Popular Electronics' font on the cover
that month:
http://www.sunrise-ev.com/photos/PopularElectronicsAug76.jpg
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com
11:13 p.m.
On Thu, May 12, 2016 at 9:38 PM, Jim Brain <brain at jbrain.com> wrote:
Not sure if I am completely understanding the concerns
with the switches,
but:
* I would install the switches and run the top nut out to the very
end, then back the inside nut up to it on the other side of the bazel
* Once all switches are installed, then insert the board and solder.
Part of the problem is that with the commonly-available switches, the
push-button has a significantly shorter bushing than the toggles.
The switches I chose for the first version had the same length
bushings, and had the V-bracket that makes it easier to assemble, but
they are much harder to source. In general, there is little selection
available when you want switches with both PCB-mount termination and a
threaded bushing, as apparently that's not a common requirement.
I'm not your market segment, but I think a better
font would be welcome. I
looked online for a bit, but saw no specific font that would have historical
value, except Popular Electronics' font on the cover that month:
http://www.sunrise-ev.com/photos/PopularElectronicsAug76.jpg
I wish I could find a high-res scan of that cover. Now that I think
about it, my friend John probably has a physical issue I could borrow
and scan.
11:30 p.m.
On 5/13/2016 1:13 AM, Eric Smith wrote:
Jim
On Thu, May 12, 2016 at 9:38 PM, Jim Brain <brain
at jbrain.com> wrote:
But, is it so
short that it would not touch the PCB when soldered? If
not, I think you're OK.
Not sure if I am completely understanding the
concerns with the switches,
but:
* I would install the switches and run the top nut out to the very
end, then back the inside nut up to it on the other side of the bazel
* Once all switches are installed, then insert the board and solder.
Part of the
problem is that with the commonly-available switches, the
push-button has a significantly shorter bushing than the toggles. 
13 May
13 May
1:18 a.m.
On Thu, May 12, 2016 at 11:38 PM, Jim Brain <brain at jbrain.com> wrote:
On 5/12/2016 9:58 PM, Eric Smith wrote:
> I just got the new boards:
>
> https://www.flickr.com/photos/22368471 at N04/albums/72157668325096875
Nice!
I'm not your market segment, but I think a better
font would be welcome.
I would agree (and I've built more than one 1802 board)
I
looked online for a bit, but saw no specific font that would have historical
value, except Popular Electronics' font on the cover that month:
http://www.sunrise-ev.com/photos/PopularElectronicsAug76.jpg
I made one of those once, about 12 years ago. I used Letraset dry
transfer letters, which is what I remember the original Elf project
had used. Someone on the list sent me a few used sheets and I used a
few more numbers.
-ethan
2:54 p.m.
On Fri, May 13, 2016 at 2:18 AM, Ethan Dicks <ethan.dicks at gmail.com> wrote:
I made one of those once, about 12 years ago. I used
Letraset dry
transfer letters, which is what I remember the original Elf project
had used. Someone on the list sent me a few used sheets and I used a
few more numbers.
I imagine almost everyone used Letraset. That doesn't help me much
because Letraset made a zillion different fonts.
In the absence of any details, I'll use some variant of Hevetica.
9:26 p.m.
On Fri, May 13, 2016 at 5:54 PM, Eric Smith <spacewar at gmail.com> wrote:
I imagine almost everyone used Letraset.
They did.
That doesn't help me much
because Letraset made a zillion different fonts.
They did.
In the absence of any details, I'll use some
variant of Hevetica.
That is probably a great start. The art from the Popular Science
article should be a good guide.
Here's a decent photo of a repro...
http://www.cosmacelf.com/_Media/elf3_big_med_hr.jpeg
Mine is missing some letters owing to how I got mine. I should figure
out what I need and re-do my front panel.
-ethan
14 May
14 May
12:02 a.m.
I wrote:
In the absence of any details, I'll use some
variant of Hevetica.
On Fri, May 13, 2016 at 10:26 PM, Ethan Dicks <ethan.dicks at gmail.com> wrote:
That is probably a great start. The art from the
Popular Science
article should be a good guide.
I can't find a decent scan of the cover of that issue.
Here's a decent photo of a repro...
http://www.cosmacelf.com/_Media/elf3_big_med_hr.jpeg
That's Bill Buzbee's ELF. He did a nice job.
I've studied it a bit more. The "R" in Helvetica isn't a good match,
and I don't like it. Adelle Sans Bold and District Std. Demi look
like better matches, but I don't want to spend that much money. I
think I'll go with Liberation Sans Bold and/or Liberation Sans Narrow
Bold. They look close enough, other than having a horizontal base bar
for the "1", and I think I can live with that.
1 a.m.
I wrote:
I think I'll go with Liberation Sans Bold and/or
Liberation Sans Narrow
Bold. They look close enough, other than having a horizontal base bar
for the "1", and I think I can live with that.
Here's a PDF showing an ELF switch panel with Liberation Sans Bold:
http://www.brouhaha.com/~eric/retrocomputing/elf/panel.pdf
The inner circles for the switches are the 250 mil diameter hole, and
the outer circle show the size of a typical internal lock washer that
would be used.
11:23 a.m.
New subject: PDP-11/34a hung bus problem.
Hi.
After being sitting dormant for 5 years in pieces, it was time
to reassemble my 11/34, but hit a problem (hung bus).
What has been done so far :
- removed all the cards from the backplane.
- vacuum the backplane.
- power up the BA11 and check the voltages.
-> LTC is ok.
-> ACLO & DCLO were 0V, replaced board in switch unit,
ACLO & DCLO now ok.
- measure voltage at back-plane with no cards, voltage reads 5.35 Volt,
trimmed them down to 5.15 Volt (no load).
- insert both CPU cards, KY11-LB card & bootstrap card, 5 full grant
cards, DL11-W and bus terminator card.
- power up the machine, voltages are 5.10 Volt, measured at the backplane.
- run light is off
- cntrl + boot shows register dump at printer.
- sending a character to the console via 777566 does print it.
All looks ok.
- power down machine, add memory (M7981, 128KW) in slot 4, replacing a
full grant card.
- power up machine -> run light is on, does not get cleared by
cntrl + halt.
- power down & replace memory with grand card -> run light is off.
- moving the memory card to slot 5 , 6, or 7 and fill the other slots
with full grant cards, -> run light does stay on.
- tried the same without the bus end termination card (as is suggested
in the processor manual), no effect :(
- tried a 2nd memory card (M8722, 128KW) in slot 4, 5, 6 or 7, no change.
- visual checking the backplane wiring did not reveal any oddity.
So what could be the problem here? The bus works without the memory,
but with it, it gets a hung bus, arghhh...
Any suggestion is welcome!
Ed
--
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9 comments
4 participants
participants (4)
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brain＠jbrain.com -
ed＠groenenberg.net -
ethan.dicks＠gmail.com -
spacewar＠gmail.com