Hi all,
I now have just acquired a VT-100 and am in the process of checking it out.
I noticed there is a capacitor that has vaporized, but I cant determine
what value it is.
I have the DEC VT-100 maintenance guide but it is very blurry in the
relevant area.
I cant even read the board designation.
This is the area of the circuit, I can trace the 2 Zener diodes on the -23V
rail, to one end of the cap, the other end seems to go to ground. The
obvious culprit is C6, but that doesn't match the mud map of the board, as
in C1x.
https://imgur.com/a/tm8mn8b
This is the capacitor in question.
It looks like C1x where x is undetermined.
I think it was a ceramic monolithic capacitor, it seems to be different to
any other caps on the board, i.e. slightly larger and a different colour
blue. When I look at this hires photos on Google images, it is the blue
capacitor circled below
Does anyone have a VT-100 and mind checking what the value of this
capacitor is please?
Ideally value and voltage or even just the nomenclature written on it, I
can work out the value and voltage from that.
Many thanks and Cheers, Martin...
Hi Kevin/Stefan/Salik
Thanks for the replies much appreciated.
Looks like there might be a few of these systems around, so will see if I can pick one up.
Willing to pay a reasonable fee for a system of course.
Thanks
Ian
Hi,
during my move, I think I lost my tape drive, which was attached to my
at&t unix pc (68000 based).
Anybody knows of the top of their head, if I could read the tapes on any
other machine? Was it anything "standard", or did they do their own at at&t?
Cheers & thanks!
Hi all,
I've had a paper tape reader for a while but never had a punch to make new
tapes, and the ones i've found are not only very large but also very
expensive. So I'm toying with the idea of making an open-source punch, but
I can't find any detailed diagrams of how the mechanism works.
I'm assuming (without any data to back it up) that there is a cam, an array
of spring-levered pins, and horizontal spacers controlled by solenoids that
bridge the gap between the cam and each punch pin when called for.
Does anyone have insight into how reliable/fast paper tape punches work?
--
Anders Nelson
+1 (517) 775-6129
www.erogear.com
Courtesy of a Raspberry Pi serving as the ND server, I am now able to
load SunOS 3.5 over the network onto my 3/260 and it is now coming up
into the OS. I am now seeing this error:
>sc0 at vme24d16 200000 vec 0x40
>sd0 at sc0 slave 0
>si0: sc_cmd: scsi bus continuously busy
>sc0: resetting scsi bus
>sd1 at sc0 slave 1
>si0: sc_cmd: scsi bus continuously busy
>sc0: resetting scsi bus
The SCSI controller is the "Sun 2" SCSI card. I saw some corrosion-ish
crap on the board and cleaned it off. It is SCSI, so, of course, I
played with termination. No change in behavior.
Is this likely to be a controller board problem or a device problem?
Are these boards picky about SCSI devices?
Any other suggestions?
alan
At 07:18 AM 5/1/2020, Hugh Pyle via cctalk wrote:
>I've cut Mylar tape with a Glowforge laser. It cuts very nicely but the
>alignment is a major hassle, plus you can only cut ~15" of tape which
>doesn't go very far. Not worth the effort. If you were to build a custom
>linear drive it might work. But also very slow.
Hmm. You could have N fixed lasers at the spots of potential holes,
and then a mechanism to move the whole assembly of them in the shape of a
single hole, drawing them all at once.
You could have one laser on that moved precisely along the hole row,
and use the same sort of mechanical motion to draw a hole.
How much laser do you need to cut paper, how much to cut mylar?
Were there any paper tape devices that did not use the sprocket holes
to move the tape?
- John
I have in my shop a small blue old Lear Sieglar terminal. I does power on,
but it gets a screen full of garbage. It is missing numerous keycaps. There
are several cracks in the case around the keyboard. Asking $200; local
pickup only. Pictures on request.
Cindy Croxton
Electronics Plus
1613 Water Street
Kerrville, TX 78028
830-370-3239 cell
sales at elecplus.com
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