I spent an half an hour today operating beyond my level of competence,
but I seemed to get away with it.
I took apart an old VT320 terminal because I wanted to measure the
display refresh rate. From disassembling the ROM I know that a frame
interrupt is passed to the microcontroller, so I thought I'd open the
case, prise apart the tube and the main PCB, connect an oscilloscope
probe to the appropriate pin on the microcontroller, power up the
terminal and get my timings.
I was reassembling the terminal when an odd rattling and whistling sound
made me dive for cover. This noise went on for about 15 seconds and then
all went quiet. I very nervously approached the terminal and finished
snapping the case together. I've not attempted to power it up since.
I had noticed that the tube bore a label claiming that it had an
implosion protection system, so several questions occur to me.
1. Is it possible that I've somehow blown the tube by shorting one of
its connections soon after disconnecting the power? I noticed that there
are a number of large capacitors on the circuit board, but I don't know
how long they take to discharge.
2. There are two sets of wires going to the CRT. One set of five (six?)
goes to a cap on the end of the tube, and another wire (HT?) goes to the
side of the tube. I took the cap off the back of the tube, but didn't
touch the wire at the side. Can that be safely disconnected?
3. Why would a mere software engineer be doing something this foolhardy?
Don't even attempt to answer that.
"Zane H. Healy" <healyzh(a)aracnet.com> wrote:
> While more or less off-topic I figure I'm not the only one that finds this
> to be of interest. Or am I the only one around here that actually is using
> all those DECserver's we've all got laying around? Also considering how
> easy it is to pickup a DECserver 200MC this might be of interest to people
> that don't even have any terminal servers at this time.
First, thanks Zane for sharing that, definitely of interest.
Yep, I'm one of those not using any of them I have laying around. In fact was
about to tear down some 200/MC's to recycle the aluminum cases and circuit
boards. If anybody here wants one, then let me know. I also have the
hardware manuals for them.
Mike
Nope, it's a 15" Torx-15 screwdriver that's an absolute must for getting the
little blighters apart. There's a couple of other Mac Opening tools too,
some of which Tony Duell uses.....can't remember the names.....
> -----Original Message-----
> From: Joe [mailto:rigdonj@intellistar.net]
> Sent: 18 September 2000 15:59
> To: classiccmp(a)classiccmp.org
> Subject: Re: RS-422 gender benders
>
>
> At 07:04 AM 9/18/00 -0700, Cameron wrote:
> >
> >By the way, Fry's sells Mac Crackers.
>
> What's that? a big hammmer? :-)
>
> Joe
>
Frank,
I keep getting this message when I try to send you a message. This has
been going on for a couple of weeks. Some messages are getting through but
others aren't.
Joe
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>Date: Mon, 18 Sep 2000 09:34:56 -0400
>
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>Date: Mon, 18 Sep 2000 09:27:20 -0500
>To: Frank McConnell <fmc(a)reanimators.org>
>From: Joe <rigdonj(a)intellistar.net>
>Subject: Re: Nice Haul!
>In-Reply-To: <200009180330.UAA24591(a)daemonweed.reanimators.org>
>References: <Joe's message of "Sun, 17 Sep 2000 20:25:06 -0500">
> <Joe's message of "Sun, 17 Sep 2000 18:49:04 -0500">
> <3.0.1.16.20000917184904.3dff6210(a)mailhost.intellistar.net>
> <3.0.1.16.20000917202506.3bef2e9c(a)mailhost.intellistar.net>
>Mime-Version: 1.0
>Content-Type: text/plain; charset="us-ascii"
>
<snip>
Well, not only was the screen dead but the analogue board too. The part #s
for the screens in the Plus, SE and Classic were the same, except the
classic was a slightly different sub-variant (E instead of D). I installed
the Classic CRT and got nothing, nix, nada, so I figured if the Classic was
mostly dead it was OK to assume the screen was too. I only thought about the
analogue board when I'd installed the Plus screen, so I swapped that too and
hey presto - working SE. I then put the Classic screen in the Plus and that
works too, so there's now a completely dead Classic available (well, the
mobo might be OK) as well as the bones of an SE! There's no point in keeping
the bust CRTs since they're beyond repair.
a
> -----Original Message-----
> From: ard(a)p850ug1.demon.co.uk [mailto:ard@p850ug1.demon.co.uk]
> Sent: 14 September 2000 18:56
> To: classiccmp(a)classiccmp.org
> Subject: Re: Mac SE screen
>
>
> >
> > > I know that the CRT in a Mac+ is a pretty standard 9" mono
> > > CRT, and that there's nothing odd about the pin
> configuration or operating
> >
> > > voltages. I suspect the SE's CRT is similar, but I've
> never had the
> > > chance to pull one of those machines to bits.
> >
> > I'll do it then, and compare the numbers and boards etc, and check
> > apple-history to make sure the resolutions were the same,
> which I think they
> > were.
>
> The resolution shouldn't matter for a monochrome CRT (there are no
> phosphor dots/stripes on such a screen). The resolution is really
> determined by the driver electronics, although the yoke is
> likely to be
> different as well (different scan rates -> different yoke
> inducatance, etc)
>
> >
> > > Incidentally, if you had 2 dead SEs and broke one of the
> CRTs, what
> > > happened to the other CRT? It's not common for them to fail
>
> [...]
>
> > The good old british postal service 'happened' to the other
> CRT. They
>
> Ah... That explains it :-(
>
> -tony
>
Yesterday Bob R. and I went out to visit an old CPM'er that I'd heard
about. He was glad to see us and GAVE us all of his old CPM stuff. Two
beautiful MicroMint SB180 systems (one with hard drive :-), a Televideo 970
terminal, a Steve Ciarcia Serial EPROMer, a case with an external 8" floppy
drive and a CompatiCard to operate it with, a Copy II PC card, a huge pile
of CPM software and a fair sized stack of manuals.
Does anyone have the setup instructions for a CompatiCard I? I'm also
looking for instructions for the Serial EPROMer. I think it may have been
published in the Feb. 1985 issue of Byte magazine.
Joe
Ta for that, but I've already got a v.clean classic and the SE will buff up
quite nicely when I get the time!
a
> -----Original Message-----
> From: Joe [mailto:rigdonj@intellistar.net]
> Sent: 18 September 2000 15:04
> To: classiccmp(a)classiccmp.org
> Subject: RE: Mac SE screen
>
>
> Adrian,
>
> Too bad you're in the UK. I have a nice Classic and a nice
> SE that are
> looking for homes.
>
> Joe
>
> At 11:53 AM 9/18/00 +0100, you wrote:
> >Well, not only was the screen dead but the analogue board
> too. The part #s
> >for the screens in the Plus, SE and Classic were the same, except the
> >classic was a slightly different sub-variant (E instead of
> D). I installed
> >the Classic CRT and got nothing, nix, nada, so I figured if
> the Classic was
> >mostly dead it was OK to assume the screen was too. I only
> thought about the
> >analogue board when I'd installed the Plus screen, so I
> swapped that too and
> >hey presto - working SE. I then put the Classic screen in
> the Plus and that
> >works too, so there's now a completely dead Classic
> available (well, the
> >mobo might be OK) as well as the bones of an SE! There's no
> point in keeping
> >the bust CRTs since they're beyond repair.
> >
> >a
> >
> >> -----Original Message-----
> >> From: ard(a)p850ug1.demon.co.uk [mailto:ard@p850ug1.demon.co.uk]
> >> Sent: 14 September 2000 18:56
> >> To: classiccmp(a)classiccmp.org
> >> Subject: Re: Mac SE screen
> >>
> >>
> >> >
> >> > > I know that the CRT in a Mac+ is a pretty standard 9" mono
> >> > > CRT, and that there's nothing odd about the pin
> >> configuration or operating
> >> >
> >> > > voltages. I suspect the SE's CRT is similar, but I've
> >> never had the
> >> > > chance to pull one of those machines to bits.
> >> >
> >> > I'll do it then, and compare the numbers and boards etc,
> and check
> >> > apple-history to make sure the resolutions were the same,
> >> which I think they
> >> > were.
> >>
> >> The resolution shouldn't matter for a monochrome CRT (there are no
> >> phosphor dots/stripes on such a screen). The resolution is really
> >> determined by the driver electronics, although the yoke is
> >> likely to be
> >> different as well (different scan rates -> different yoke
> >> inducatance, etc)
> >>
> >> >
> >> > > Incidentally, if you had 2 dead SEs and broke one of the
> >> CRTs, what
> >> > > happened to the other CRT? It's not common for them to fail
> >>
> >> [...]
> >>
> >> > The good old british postal service 'happened' to the other
> >> CRT. They
> >>
> >> Ah... That explains it :-(
> >>
> >> -tony
> >>
> >
>
It was a separate box mounted vertically in its own table. It should be
obvious whether it's still there or not.
> -----Original Message-----
> From: Nick Oliviero [mailto:oliv555@arrl.net]
> Sent: 16 September 2000 00:15
> To: classiccmp(a)classiccmp.org
> Subject: Re: VAX 8900 booter
>
>
> Thanks. I don't have one of those, I'll check into whether its
> still in the cabinet.
>
> Nick
>
> ajp166 wrote:
>
> > I believe it used a pro350 or 380 with a special interface board set
> > as a system console. Pros are PDP-11 FYI.
> >
> > Allison
> >
> > -----Original Message-----
> > From: Nick Oliviero <oliv555(a)arrl.net>
> > To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org>
> > Date: Thursday, September 14, 2000 8:18 PM
> > Subject: VAX 8900 booter
> >
> > >Anyone know what boot device was installed in this ?
> > >I know that earlier Vaxen used PDP11s. A quick search
> > >of the net yielded little information about this model.
> > >
> > >I've got a line on one about to be dismantled and want
> > >to find out if theres anything in it worth salvaging. Don't
> > >have access to it, its 1000 miles away. But I have a friend
> > >there willing to scout it for me. Thanks.
> > >
> > > Nick
> > >
>
Dammit - I haven't got the space!
> -----Original Message-----
> From: Bill Bradford [mailto:mrbill@mrbill.net]
> Sent: 15 September 2000 12:36
> To: classiccmp(a)classiccmp.org
> Subject: PDP-11 *free* in the UK
>
>
> An email I received @ pdp11.org:
> - - - -
> From engdesk(a)intelfaxdev.co.uk Fri Sep 15 06:16:09 2000
>
> From: "Andrew Bailey" <engdesk(a)intelfaxdev.co.uk>
>
> To: <mrbill(a)pdp11.org>
>
> Subject: We have a PDP11 that needs a good home
>
> Date: Fri, 15 Sep 2000 12:08:38 +0100
>
>
>
> We have three large, heavy pieces of computer equipment
> marked PDP11/44, TS05
> +and RL02. If there is anybody in the UK who wants them,
> please drop us a line.
> +We will even give you a hand getting them into the van.
>
> - - - -
>
> If anyone's interested in that area, please get in touch with
> Mr. Bailey.
>
> --
> Bill Bradford
> mrbill(a)mrbill.net
> Austin, TX
>
--- "Richard A. Cini, Jr." <rcini(a)optonline.net> wrote:
> Hello, all:
>
> Some months back, I had a deal on several AIM65 systems. Well, my contact
> sent me a message indicating that he had one more available. It's in a
> custom-molded case with power supply. The price is $100 + S/H from New
> Jersey.
I got one of these... really nice. I'm very happy with it.
(just an un-paid testimonial... ;-)
-ethan
=====
Even though my old e-mail address is no longer going to
vanish, please note my new public address: erd(a)iname.com
The original webpage address is still going away. The
permanent home is: http://penguincentral.com/
See http://ohio.voyager.net/ for details.
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