Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Robert Jarratt
The M24 I got the other day has the bus converter, whereas the other M24
that I already had does not. I bought a bus converter for the "old" one, but
then realised I didn't have any mounting bushes or spacers in order to
install it. I thought of removing some of the bushes from the new one to
share with the old one, it wouldn't be as good but at least I would be able
to install the converter.

 

It looks like I might need some kind of special tool to remove the bushes
from the new machine. Is there a way to do this with ordinary tools? Does
anyone know if the mounting bushes are any kind of standard part that could
still be bought somewhere?

 

Thanks

 

Rob



RE: PDP-8 panels

2016-03-25 Thread William Maddox
I received one of the new panels from Rob, and it is nearly indistinguishable 
from the original.  It captures the matte finish of the original exactly.  
Fantastic!

>_PDP-8 New Products under consideration _
>
>1. Front panels for any of the other PDP-8 models, Including the 
>Straight 8 but excluding PDP-8A.

I'd like to cast a vote for the PDP8/I.   I have a machine with a completely 
trashed panel, where the clear-coat has become crinkly, cracked, and dark.

I suspect there may be a market for these panels for simulator-backed front 
panel reproductions.   Oscar Vermuelen's excellent PiDP-8 uses a reduced-size 
PDP8/I panel, but a full-sized replica would be even nicer.  The PDP8/I has the 
most beautiful and complete panel of any of the 8s, perhaps of any minicomputer.

--Bill





Re: PDP-8 panels

2016-03-25 Thread Rod Smallwood

Hi Bill
   Thank you for the kind words.
What you have is Version 3. Version 1 shipped in limited quantities.
Version 2 never shipped because Chessie (My silk screen expert) and
I did not like what happend when we put matt black on the front.

I had to sit down and think about that one.
I have a real 8/m panel (Loaned by a kind list member)
Being as old as it was it was scratched in a few places.
I noticed that although it was not matt black on the front there was a 
coating of some sort.

So we ordered some translucent ink. The result was awful.
It was good for covering the lamp holes on the back though.

Then something in my somewhat senior brain
(I started with papertape and punched cards)
Reminded me that you can get perspex with surface finishes.
So I get on the phone to my  panel supplier and she sends me down some 
samples.


One looks good so off down to the silk screen shop.
We put the normal semi gloss on the back and stuck it in the drier.
Then mins later Chessie fishes it out of the drier and says something 
very unladylike,

Followed by It looks matt on the front. It really does!!

After that it was back to the normal six step screen - dry - screen process.
Why did the translucent ink not work? They don't make the right one anymore
because as we found out you can get etched silk finish perspex!!!

I always confuse 8/i and 8/L. Which one did you want?
I know Oscar and I'm sure he said he had no problem
with me doing full size panels as he only did the cut down version.

I'm now going to build for stock (8/e, 8/f and 8/m)
We have custom packaging so we can ship pre-packed same day.

Regards

Rod (Panelman) Smallwood


with me making full size panels

On 25/03/2016 08:28, William Maddox wrote:

I received one of the new panels from Rob, and it is nearly indistinguishable 
from the original.  It captures the matte finish of the original exactly.  
Fantastic!


_PDP-8 New Products under consideration _

1. Front panels for any of the other PDP-8 models, Including the
Straight 8 but excluding PDP-8A.

I'd like to cast a vote for the PDP8/I.   I have a machine with a completely 
trashed panel, where the clear-coat has become crinkly, cracked, and dark.

I suspect there may be a market for these panels for simulator-backed front 
panel reproductions.   Oscar Vermuelen's excellent PiDP-8 uses a reduced-size 
PDP8/I panel, but a full-sized replica would be even nicer.  The PDP8/I has the 
most beautiful and complete panel of any of the 8s, perhaps of any minicomputer.

--Bill







Re: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Dave Wade
Could they be 3d printed? Pictures might help...
On 25 Mar 2016 09:20, "Robert Jarratt"  wrote:

> The M24 I got the other day has the bus converter, whereas the other M24
> that I already had does not. I bought a bus converter for the "old" one,
> but
> then realised I didn't have any mounting bushes or spacers in order to
> install it. I thought of removing some of the bushes from the new one to
> share with the old one, it wouldn't be as good but at least I would be able
> to install the converter.
>
>
>
> It looks like I might need some kind of special tool to remove the bushes
> from the new machine. Is there a way to do this with ordinary tools? Does
> anyone know if the mounting bushes are any kind of standard part that could
> still be bought somewhere?
>
>
>
> Thanks
>
>
>
> Rob
>
>


RE: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Robert Jarratt


> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Dave
> Wade
> Sent: 25 March 2016 12:16
> To: General Discussion: On-Topic and Off-Topic Posts
> 
> Subject: Re: Olivetti M24 Mounting Bushes for Bus Converter
> 
> Could they be 3d printed? Pictures might help...


There are actually two varieties. The plastic ones probably could, but actually 
I was talking about the steel ones which probably can't. I have put it all away 
again for now so I can't get any pictures right now. I'll get it out again 
later, if I can, and post some pics.

Regards

Rob


> On 25 Mar 2016 09:20, "Robert Jarratt"  wrote:
> 
> > The M24 I got the other day has the bus converter, whereas the other
> > M24 that I already had does not. I bought a bus converter for the
> > "old" one, but then realised I didn't have any mounting bushes or
> > spacers in order to install it. I thought of removing some of the
> > bushes from the new one to share with the old one, it wouldn't be as
> > good but at least I would be able to install the converter.
> >
> >
> >
> > It looks like I might need some kind of special tool to remove the
> > bushes from the new machine. Is there a way to do this with ordinary
> > tools? Does anyone know if the mounting bushes are any kind of
> > standard part that could still be bought somewhere?
> >
> >
> >
> > Thanks
> >
> >
> >
> > Rob
> >
> >



RE: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread tony duell

> > Could they be 3d printed? Pictures might help...
> 
> There are actually two varieties. The plastic ones probably could, but 
> actually I was
>  talking about the steel ones which probably can't. I have put it all away 
> again for 
> now so I can't get any pictures right now. I'll get it out again later, if I 
> can, and post 
> some pics.

Could you turn them on a lathe. I assume they're quite small.

-tony


RE: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Robert Jarratt

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of tony
duell
> Sent: 25 March 2016 12:59
> To: General Discussion: On-Topic and Off-Topic Posts
> 
> Subject: RE: Olivetti M24 Mounting Bushes for Bus Converter
> 
> 
> > > Could they be 3d printed? Pictures might help...
> >
> > There are actually two varieties. The plastic ones probably could, but
> > actually I was  talking about the steel ones which probably can't. I
> > have put it all away again for now so I can't get any pictures right
> > now. I'll get it out again later, if I can, and post some pics.
> 
> Could you turn them on a lathe. I assume they're quite small.
> 
> -tony
> =

Perhaps, if I had a lathe. I do have a locksmith friend who could possibly
make them, but it is the way they go into the base that is problematic. I
will have to post some pictures.

Regards

Rob



Re: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Todd Goodman
* Robert Jarratt  [160325 08:29]:
> 
> 
> > -Original Message-
> > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Dave
> > Wade
> > Sent: 25 March 2016 12:16
> > To: General Discussion: On-Topic and Off-Topic Posts
> > 
> > Subject: Re: Olivetti M24 Mounting Bushes for Bus Converter
> > 
> > Could they be 3d printed? Pictures might help...
> 
> 
> There are actually two varieties. The plastic ones probably could, but 
> actually I was talking about the steel ones which probably can't. I have put 
> it all away again for now so I can't get any pictures right now. I'll get it 
> out again later, if I can, and post some pics.
> 
> Regards
> 
> Rob

Do you mean stand-offs?

Like:

http://www.digikey.com/product-detail/en/keystone-electronics/1813/36-1813-ND/303673

?


Re: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Chuck Guzis
I'll have to open up my 6300 to see what they are, but my initial 
impression is that rivnuts might be just the ticket.  I'll check later, 
however.


--Chuck



Free XT Machine

2016-03-25 Thread John Ball
I'm up in Kamloops but even at the cost of gas (about $120 tghere and back)
I'm tempted to go down and pick it up if it has not already happened.
Failing that, There's a fantastic place at 304 Victoria drive that will
accept the machine if you can't find a home for it. I can vet for them as
their specialty is older machines.

-John B.


>IBM 5160 system
>IBM 5151 monitor
>IBM clicky keyboard.
>
>Dual floppy with hard drive, but the hard drive is erratic, perhaps a
stiction issue.
>Also some extra floppy drives and untested hard drives.
>
>Mentioned this last year, it's still available, but may soon end up in
scrap if it's not taken.



RE: Free XT Machine

2016-03-25 Thread John Ball
>I'm up in Kamloops but even at the cost of gas (about $120 tghere and back)
I'm tempted to go down and pick >it up if it has not already happened.
Failing that, There's a fantastic place at 304 Victoria drive that
>will accept the machine if you can't find a home for it. I can vet for them
as their specialty is older
>machines.

Oh butts, that was to be emailed to him directly. Sorry guys. >_>'



RE: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Robert Jarratt
> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Chuck
> Guzis
> Sent: 25 March 2016 15:31
> To: General Discussion: On-Topic and Off-Topic Posts
> 
> Subject: Re: Olivetti M24 Mounting Bushes for Bus Converter
> 
> I'll have to open up my 6300 to see what they are, but my initial impression 
> is
> that rivnuts might be just the ticket.  I'll check later, however.
> 
> --Chuck

I looked up rivnuts and they certainly look similar. They are definitely not 
standoffs though. I shall look closer at rivnuts.

Thanks

Rob



RE: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Fred Cisin
I looked up rivnuts and they certainly look similar. They are definitely 
not standoffs though. I shall look closer at rivnuts.


also look at nutserts.

Riv-nuts are pop-rivets with a threaded center.  Usable through sheet 
metal, and into blind holes (very carefully)

Nutserts call for drilling and threading a hole and screwing them in.

I'm assuming that you are talking about threaded inserts in a plastic 
piece?






RE: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Robert Jarratt


> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Fred
Cisin
> Sent: 25 March 2016 19:10
> To: General Discussion: On-Topic and Off-Topic Posts
> 
> Subject: RE: Olivetti M24 Mounting Bushes for Bus Converter
> 
> > I looked up rivnuts and they certainly look similar. They are
> > definitely not standoffs though. I shall look closer at rivnuts.
> 
> also look at nutserts.
> 
> Riv-nuts are pop-rivets with a threaded center.  Usable through sheet
metal,
> and into blind holes (very carefully) Nutserts call for drilling and
threading a
> hole and screwing them in.
> 
> I'm assuming that you are talking about threaded inserts in a plastic
piece?
> 

I have posted the pictures here:
https://onedrive.live.com/redir?resid=FC758A5A91B91301!5776&authkey=!AOs6cfg
8p_qyB5Q&ithint=folder%2cjpg

The pictures show three things:

1. The square holes that the mountings go into.
2. The top and bottom side of the steel mountings.
3. The top and bottom sides of the nylon (?) mountings.

I find myself to really need the steel mountings to be able to mount the bus
converter, I am hopeful that I can move a couple of existing nylon ones.

Regards

Rob



Re: Free XT Machine

2016-03-25 Thread Ian S. King
I'm waiting to hear back, but I think Brent and I have an agreement on
this.  :-)

On Fri, Mar 25, 2016 at 10:34 AM, John Ball  wrote:

> >I'm up in Kamloops but even at the cost of gas (about $120 tghere and
> back)
> I'm tempted to go down and pick >it up if it has not already happened.
> Failing that, There's a fantastic place at 304 Victoria drive that
> >will accept the machine if you can't find a home for it. I can vet for
> them
> as their specialty is older
> >machines.
>
> Oh butts, that was to be emailed to him directly. Sorry guys. >_>'
>
>


-- 
Ian S. King, MSIS, MSCS, Ph.D. Candidate
The Information School 
Dissertation: "Why the Conversation Mattered: Constructing a Sociotechnical
Narrative Through a Design Lens

Archivist, Voices From the Rwanda Tribunal 
Value Sensitive Design Research Lab 

University of Washington

There is an old Vulcan saying: "Only Nixon could go to China."


Re: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Chuck Guzis

On 03/25/2016 02:25 PM, Robert Jarratt wrote:


I have posted the pictures here:
https://onedrive.live.com/redir?resid=FC758A5A91B91301!5776&authkey=!AOs6cfg



8p_qyB5Q&ithint=folder%2cjpg


The pictures show three things:

1. The square holes that the mountings go into. 2. The top and bottom
side of the steel mountings. 3. The top and bottom sides of the nylon
(?) mountings.

I find myself to really need the steel mountings to be able to mount
the bus converter, I am hopeful that I can move a couple of existing
nylon ones.


Ah, thanks for saving me the trouble of digging out my own 6300.

The exact nylon standoffs might be a bit difficult, but the metal parts 
could easily be replaced with plain old threaded hex standoffs.  The 
original metal standoffs are press-fitted into place and my guess that 
they'll be difficult to find, even if you do own an appropriate press


The great thing is that the holes for both types are recessed on the 
bottom, so that getting a good mounting using a washer-head machine 
screw should be no problem. I've got bags of aluminum hex standoffs of 
various sizes and find them to be invaluable.  Jameco also offers a 
somewhat more limited selection.


Here's Mouser's 578 pages of standoff choices:

http://www.mouser.com/Electromechanical/Hardware/Standoffs-Spacers/_/N-aictf

So maybe not original, but close enough functionally.

--Chuck




Re: Free XT Machine

2016-03-25 Thread Brent Hilpert
Sorry to leave anybody anticipating, busy packing house to deadline.
Yes, Ian was first in with local transfer so it's his at this point.

On 2016-Mar-25, at 2:54 PM, Ian S. King wrote:

> I'm waiting to hear back, but I think Brent and I have an agreement on
> this.  :-)
> 
> On Fri, Mar 25, 2016 at 10:34 AM, John Ball  wrote:
> 
>>> I'm up in Kamloops but even at the cost of gas (about $120 tghere and
>> back)
>> I'm tempted to go down and pick >it up if it has not already happened.
>> Failing that, There's a fantastic place at 304 Victoria drive that
>>> will accept the machine if you can't find a home for it. I can vet for
>> them
>> as their specialty is older
>>> machines.
>> 
>> Oh butts, that was to be emailed to him directly. Sorry guys. >_>'
>> 
>> 
> 
> 
> -- 
> Ian S. King, MSIS, MSCS, Ph.D. Candidate
> The Information School 
> Dissertation: "Why the Conversation Mattered: Constructing a Sociotechnical
> Narrative Through a Design Lens
> 
> Archivist, Voices From the Rwanda Tribunal 
> Value Sensitive Design Research Lab 
> 
> University of Washington
> 
> There is an old Vulcan saying: "Only Nixon could go to China."



Re: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread dwight
Rob, many of your messages are blank.
Dwight


From: cctalk  on behalf of Robert Jarratt 

Sent: Friday, March 25, 2016 2:25 PM
To: 'General Discussion: On-Topic and Off-Topic Posts'
Subject: RE: Olivetti M24 Mounting Bushes for Bus Converter

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Fred
Cisin
> Sent: 25 March 2016 19:10
> To: General Discussion: On-Topic and Off-Topic Posts
> 
> Subject: RE: Olivetti M24 Mounting Bushes for Bus Converter
>
> > I looked up rivnuts and they certainly look similar. They are
> > definitely not standoffs though. I shall look closer at rivnuts.
>
> also look at nutserts.
>
> Riv-nuts are pop-rivets with a threaded center.  Usable through sheet
metal,
> and into blind holes (very carefully) Nutserts call for drilling and
threading a
> hole and screwing them in.
>
> I'm assuming that you are talking about threaded inserts in a plastic
piece?
>

I have posted the pictures here:
https://onedrive.live.com/redir?resid=FC758A5A91B91301!5776&authkey=!AOs6cfg
8p_qyB5Q&ithint=folder%2cjpg

The pictures show three things:

1. The square holes that the mountings go into.
2. The top and bottom side of the steel mountings.
3. The top and bottom sides of the nylon (?) mountings.

I find myself to really need the steel mountings to be able to mount the bus
converter, I am hopeful that I can move a couple of existing nylon ones.

Regards

Rob



also free for pickup: macClassic

2016-03-25 Thread Brent Hilpert
I believe it has the nothing-but-horizontal-bars-in-display problem.
Picked it up in anticipation of working on it someday but I have too much to do.
With keyboard.
I think the system disks and manuals are also around.

Sorry, but I just can't get into packing&shipping stuff this size.



couple of Coco machines also free for pickup

2016-03-25 Thread Brent Hilpert
Vancouver, B.C. region, as with the other stuff.



Re: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Fred Cisin

Sorry for top posting, . . .

Does what you just forwarded look blank to you?

Search it for:
"I have posted the pictures here:"
ending with
"Regards
Rob"



On Fri, 25 Mar 2016, dwight wrote:


Rob, many of your messages are blank.
Dwight


From: cctalk  on behalf of Robert Jarratt 

Sent: Friday, March 25, 2016 2:25 PM
To: 'General Discussion: On-Topic and Off-Topic Posts'
Subject: RE: Olivetti M24 Mounting Bushes for Bus Converter


-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Fred

Cisin

Sent: 25 March 2016 19:10
To: General Discussion: On-Topic and Off-Topic Posts

Subject: RE: Olivetti M24 Mounting Bushes for Bus Converter


I looked up rivnuts and they certainly look similar. They are
definitely not standoffs though. I shall look closer at rivnuts.


also look at nutserts.

Riv-nuts are pop-rivets with a threaded center.  Usable through sheet

metal,

and into blind holes (very carefully) Nutserts call for drilling and

threading a

hole and screwing them in.

I'm assuming that you are talking about threaded inserts in a plastic

piece?




I have posted the pictures here:
https://onedrive.live.com/redir?resid=FC758A5A91B91301!5776&authkey=!AOs6cfg
8p_qyB5Q&ithint=folder%2cjpg

The pictures show three things:

1. The square holes that the mountings go into.
2. The top and bottom side of the steel mountings.
3. The top and bottom sides of the nylon (?) mountings.

I find myself to really need the steel mountings to be able to mount the bus
converter, I am hopeful that I can move a couple of existing nylon ones.

Regards

Rob


RE: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Robert Jarratt
> 
> Ah, thanks for saving me the trouble of digging out my own 6300.
> 
> The exact nylon standoffs might be a bit difficult, but the metal parts
could
> easily be replaced with plain old threaded hex standoffs.  The original
metal
> standoffs are press-fitted into place and my guess that they'll be
difficult to
> find, even if you do own an appropriate press


I was wondering if these are pressed in, or if the serrated edge around the
bottom of the mounting indicated some kind of two-part component with a
special tool to screw the two halves together. Sounds like it is a single
part :-(

> 
> The great thing is that the holes for both types are recessed on the
bottom,
> so that getting a good mounting using a washer-head machine screw should
> be no problem. I've got bags of aluminum hex standoffs of various sizes
and
> find them to be invaluable.  Jameco also offers a somewhat more limited
> selection.
> 
> Here's Mouser's 578 pages of standoff choices:
> 
> http://www.mouser.com/Electromechanical/Hardware/Standoffs-
> Spacers/_/N-aictf
> 
> So maybe not original, but close enough functionally.
> 
> --Chuck

I hadn't considered doing something like this. In the end I am most
interested in functionality as long as I don't have to permanently alter
anything.

Thanks for the suggestion.

Rob



Re: couple of Coco machines also free for pickup

2016-03-25 Thread dwight

I'm thinking that maybe someone should sit outside
your place with a pickup truck and camper shell.
Dwight

From: cctalk  on behalf of Brent Hilpert 

Sent: Friday, March 25, 2016 3:26 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: couple of Coco machines also free for pickup

Vancouver, B.C. region, as with the other stuff.



Re: Olivetti M24 Mounting Bushes for Bus Converter

2016-03-25 Thread Mike Stein
- Original Message - 
From: "Robert Jarratt" 
Sent: Friday, March 25, 2016 7:10 PM


...
>> Here's Mouser's 578 pages of standoff choices:
>> 
>> http://www.mouser.com/Electromechanical/Hardware/Standoffs-
>> Spacers/_/N-aictf
>> 
>> So maybe not original, but close enough functionally.
>> 
>> --Chuck
> 
> I hadn't considered doing something like this. In the end I am most
> interested in functionality as long as I don't have to permanently alter
> anything.

I just cut what I need from the barrel of an old dried-out ball point pen, with 
self-tapping screws, long all-the-way-through screws, or expanding plastic 
standoffs glued in the end(s), depending on the situation...

m


Re: DEC H7104-D debugging...

2016-03-25 Thread Josh Dersch

On 3/24/16 3:25 AM, Mattis Lind wrote:

So I had a few minutes tonight to investigate a few things:

- The startup PSU is running, and the relay in the 5V supply is firing and
stays energized until the supply is powered off.
- The +5V, and +/-12V bias voltages are being properly generated. This
makes sense, since the 2.5V supply is working fine.  From my understanding
of the supply, this means the 300VDC is also present (also validated by the
relay firing.)
- The 20Khz clock generated on the bias board is present (measured from
pin 8 of J1 on on the bias board), at the proper rate and duty cycle.
- 5V AC and DC LO signals (measured at J1) are .3 and .9V, respectively.


Then a lot things seems to be working.
It does seem that way.  Thanks for the suggestions, I have a few (likely 
head-scratchingly obvious) questions below.  This is not my area of 
expertise by a long shot so some of these things are less than obvious 
to me.  Thanks for being patient :).



Is the main chopper transistor driven?
How do I identify which transistor is the main chopper?  I've looked 
through the schematic and the tech reference and I've come up empty.





First check that you have a signal on the primary side of the pulse
transformer  T2 on the mother board? Driven through B22 / B24 from the
control board. Q6 collector.
These are the pins on J4 (on the motherboard) labeled "-TRIGGER" and 
"+TRIGGER" ?  Is this safe to probe with a standard 10x oscilloscope 
probe (assuming I bring some leads out to where it's safe...)?




If not then check backwards towards the NE556, Q6 and Q15. E9 pin 9 and pin
5. E8 pin 3. These outputs are OR:ed together via diodes and drive Q15 base.


Makes sense.



If yes then you need to investigate the secondary side of the pulse
transformer T2 on the mother board. (Now it is getting dangerous if you are
not careful). Is there base drive on the power transistors?

What precautions do you recommend taking here?

Thanks again.  I may have some time this weekend to play with this, but 
I have family coming to visit, so probably not :).  I'll let you know 
how I get on if I do, though...


- Josh






So far, so good.  I also measured the 5V Overcurrent and 5V Crowbar on J1
(pins 2 and 19) and they're at 12V and 8V respectively.  I'm not sure I
understand what this indicates; the Overcurrent lamp is not illuminated on
the power controller, for example, and per the tech manual (section 4.4.2)
if an overvoltage occurs and the crowbar kicks in, the supply should shut
down for ~1 second, which I'm not seeing any indications of (I'm not seeing
the voltage reach anything over .2V with a small load attached).  The
overcurrent protection appears to work similarly.  I don't see an
indication of what the levels for the signals on J1 are supposed to be,
however.


The NE555 will trigger on a low going TRIG signal, so if either the CROWBAR
SENSE (which is generated by a SCR that sinks this singal to ground when
fired) OR the +5V OVERCURRENT goes low it will trigger. These signals are
active low. I.e you don't have a over current or over voltage condition.


I'll hopefully have more time to debug later this week, thought I'd report
my findings and see if anyone has any bright ideas.


Good luck!

/Mattis




Thanks as always,
- Josh