I was hoping there might be some sort of preassembled optical sensor array
available with the right spacing for paper tape holes, but maybe that is
hoping for too much. If you build one with discrete sensors, is it easy to
find ones that are narrow enough to stack side to side with the correct
spacing?
>Hi
> Ahh, such concepts as make one come to mind. You could
>scrap a number of mice for the optical sensors ( two for
>each axis, 4 total per mouse ) or you could buy photo
>transistors from Jameco. In a pinch, the clear lensed
>LED's make reasonable detectors.
> Use a little imagination.
>Dwight
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As promised in a previous message, last Friday I went to the office of the
guy with all the VMS manuals. It took me two trips, but when it was over, 11
boxes of varying sizes full of VMS and VAX docs sat in my garage.
Unfortunately, some of the older orange and grey binders were empty, and it
appears that I now only have full docs for VMS from version 6 to 7.2. Also
in there was one manual for MicroVMS 4.something. I didn't get everything,
so I will go back next Tuesday to finish up.
Today the university surplus shop had put out for sale the MicroVAX II
system that I had seen last week. It consists of a BA23 with RX50 and RD5x,
a Fujitsu(?) Eagle hard drive, and a Kennedy 9600 tape unit (looks like a
DEC TS05). Great, right? Well, un^H^Hfortunately, I had a job interview
today, scheduled such that I would be unable to attend the sale. I found a
trustworthy-looking person and bribed them to proxy-purchase the item for me
during the sale. It worked.
So tomorrow morning I will pick up the SA900 disk cabinet for the VAX 6K I
got last week, and now a MicroVAX II system. And there's no school for a
couple of days. Another great week.
The job interview took 3 hours and 20 minutes. I did well.
--
Jeffrey Sharp
On Nov 26, 15:45, John Allain wrote:
> FWIW here's some of the fuse types I've found:
>
> AGC 3AG 3AD GLH MTH MSL, none of which I know
3AG means "Automobile Glass size 3". I suspect those designations have
more to do with heating, rupturing, voltage, overload capacity, and most
especially materials, shape, and dimensions, than with "slow" or "fast".
> for the 1.6A MDL I have
> 2A "plain", 2.5A "plain", MSL 2A, MDL 2A
> as candidates. I guess a slightly higher value is OK when
> replacing a slo with a non slo?
Maybe, but how much is "slightly"? The slow-blow was probably intended to
cope with short-duration inrush current, but reliably blow if the current
was too high for more than perhaps a few seconds. A "fast" fuse will
typically blow at 250% - 350% of the nominal value within 1-2 seconds, but
a "very fast" fuse might blow within 0.2 seconds. I've seen some "very
fast" fuses described as blowing at 1000% current within 0.001 seconds.
That's only 10 times nominal current rating, so it wouldn't allow for much
of an inrush current! As far as I know (and I am not an expert, just
someone who is sad enough to read lots of catalogues), the difference
between slow/medium/fast/very fast is primarily tolerance to short-duration
overloads like that, ie like inrush current.
> Also I imagine all of those letter codes are different blow rates?
Nope, see above.
Fuses aren't expensive. I'd try to find the right one.
--
Pete Peter Turnbull
Network Manager
University of York
>From: "Steven Edwards" <chessnotation(a)mac.com>
>
>Greetings to the list:
>
>It looks like the IMSAI Series Two (the "S2") is nearing its first
>production run. (See http://imsai.net/ and
>http://groups.yahoo.com/group/imsaiusergroup/)
>
>I've ordered one of these as a replacement of sorts for the IMSAI 8080
>I assembled back in 1976 but managed to, uh, "lose" in the early 1980s.
> It's been a long time since I've had a chance to fool around with a
>machine equipped with a real front panel.
>
>I had thought I'd seen about every S-100 machine ever made, but I
>recently came across a net reference to the Ithaca Intersystems DPS-1.
>It looks almost identical to the IMSAI 8080 except that the DPS-1 front
>panel is styled more in the way of Digital's later PDP models. I note
>that the DPS-1 PSU is somewhat different from the IMSAI 8080, but other
>than that. the internals seem to be very similar.
>
>So, are there any other IMSAI 8080 fans on the list?
>
Hi
I have one that I fixed the front panel, a number of bad RAMs,
and added an extra RAM card to bring it to 64K. I then read the
ROM's in the disK controller ( state machine, not uP ) and
figured out how to format, read and write disk. I then wrote
my own BIOS and combined it with the CP/M I got from the net.
Ya, there are a few IMSAI fans here. I'll have to admit, I'm
not overly excited about the IMSAI series two but I do wish
them the best of luck.
Dwight
Hi
One thing to reflect on. In my hand, right now, is
a small board with three major parts and a total of
six IC's. I have at home, an IMSAI with 64K of RAM.
This board has 128K RAM, 128K FLASH and a processor
that runs at a clock speed that is 20 times as fast.
The board was made in '96.
In retrospect, I don't think software has made even
one tenth that improvement ( most is not as useful ).
Just more thoughts
Dwight
Can anyone provide me information on this board,
Approximately 4in X 3 1/4 in, plugs into a adapter that replaces the
processor, marked "Surprise" 1986 Maynard Electronics, INC. Arrived in an
aged IBM PC. It has a NEC V20 chip.
Also, anybody interested in,
Quadram Quadboard, complete but rather battered.
Memory Module, 16 meg IBM part # 11S9111010784AF05P8A 02K2288 DIMM
16M
Free for personal use, not for resale
Rich Stephenson
loedman1(a)juno.com
Greetings to the list:
It looks like the IMSAI Series Two (the "S2") is nearing its first
production run. (See http://imsai.net/ and
http://groups.yahoo.com/group/imsaiusergroup/)
I've ordered one of these as a replacement of sorts for the IMSAI 8080
I assembled back in 1976 but managed to, uh, "lose" in the early 1980s.
It's been a long time since I've had a chance to fool around with a
machine equipped with a real front panel.
I had thought I'd seen about every S-100 machine ever made, but I
recently came across a net reference to the Ithaca Intersystems DPS-1.
It looks almost identical to the IMSAI 8080 except that the DPS-1 front
panel is styled more in the way of Digital's later PDP models. I note
that the DPS-1 PSU is somewhat different from the IMSAI 8080, but other
than that. the internals seem to be very similar.
So, are there any other IMSAI 8080 fans on the list?
I've picked up some miscellaneous Qbus modules which seem to be related
to data acquisition. They're made by Data Translation: DT2768, DT2769,
and DT5712. From what I can find online, the DT2769 appears to be a
realtime clock interface compatible with DEC's KWV11-C; I assume this is
fairly useless without the RTC. I can't find anything on the DT2768,
and the DT5712 is an AD/DA converter of some sort.
Does anyone have details or manuals on these boards? For a long time
now I've wanted to use an AD/DA Qbus module as a primitive sort of
soundcard in one my Qbus VAXen. I'm not sure if the DT5712 would be
suitable for the task; hopefully it is. This would also give me a
/great/ excuse for learning how to write device drivers under NetBSD/vax.
Thanks for any info or tips.
-brian.
Hi Glen
There isn't much application for things with this spacing.
Remember, you will most likely be connecting this to a
uP. You really don't need to space then in a straight
line. You can stager them and reassemble the entire
byte width afterwards.
Another though would be to use one of the linear arrays,
used in scanners. Most of these are about as wide as
a paper tape. You could use a collimated source and
drag the tape directly over the array. You'd need
to do a little image processing but it shouldn't be too
difficult.
There are some mechanical options that might work as well.
Like I said, use some imagination.
Dwight
>From: "Glen Slick" <glenslick(a)hotmail.com>
>
>I was hoping there might be some sort of preassembled optical sensor array
>available with the right spacing for paper tape holes, but maybe that is
>hoping for too much. If you build one with discrete sensors, is it easy to
>find ones that are narrow enough to stack side to side with the correct
>spacing?
>
>
>>Hi
>> Ahh, such concepts as make one come to mind. You could
>>scrap a number of mice for the optical sensors ( two for
>>each axis, 4 total per mouse ) or you could buy photo
>>transistors from Jameco. In a pinch, the clear lensed
>>LED's make reasonable detectors.
>> Use a little imagination.
>>Dwight
>
>
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