Not so much related to classic hardware directly, but instead the
*documentation* for classic hardware *and* software:
OK, let's say I've got a couple thousand sheets of microfiche, 4" x 5".
Each sheet contains ~200 paper pages of text and drawings. I want to digitize
at least part of this, possibly OCR'ing it too.
Each 8.5" x 11" printed page on the microfiche is about 0.15" x 0.2",
so the magnification factor is about 50. That means if I want the equivalent
of a 75 DPI scan of the full-size version, that I need to scan the microfiche
at about 4000 DPI. The el-cheapo (i.e. a couple hundred $) scanners I see
on the shelves here seem to top out at 2400 DPI.
And 4000 DPI is the "minumum acceptable" number in my above calculation. If
I can do 4 times better than that, so much the better. In my experience
most 75 DPI scans of 8.5" x 11" text don't OCR well at all, you need more
resolution.
So what are my choices for higher-resolution scanners? My *other* hobby
happens to be large-format photography, so if the resulting scanner is also
good for 4" x 5" negatives and/or transparencies I won't complain :-).
It looks like there are 35mm film scanners with 2700 or 3000 DPI resolutions
available for a few thousand, but I think I need to do better than that.
Of course, I can go in the darkroom and enlarge the microfilm, but doing
that for each of the thousands of sheets is going to be tedious. Yeah, I
know, it's already a tedious job!
Finally, do *any* scanners have documented interfaces? i.e. say I find myself
a nice SCSI-connected high-speed high-resolution scanner. Am I going to be
reduced to point-and-drool with Windows 98, or can I actually hook the
scanner up to a real computer? We're talking about many tens or hundreds
of gigabytes of data here, so I'm willing to invest some effort to automate
the acquire/compress/archive process.
Tim.
> > > Has anyone ever seen a splicing jig and tape (or any other form of
repair
> > > kit) for the tape cassettes (HP82176??) used in the HP82161 tape
drive.
> > > I'm trying to read some old tapes and the magnetic tape on one of them
> > > has come unstuck from the leader. I think it would be possible to
stick
> > > them together again.
> >
> > How wide is the tape? If it's not too narrow, you could try 1/2" audio
>
> I think I've been lucky for once. I cracked open the cassette and
extracted
> the ends of the tape. I held them against the tape in a random
> compact cassette [1] and they seem to be the same width. Which means I
> can use a cassette tape splicing block and tape. I know I have one of
> those _somewhere_, but even if I can't find it, I don't think they're
> particularly hard to get... I've not tried it yet, but it's
> well worth a try.
I'm a little surprised that some digital casettes were manufactured
using the sonic-welding technique, instead of using screws to hold
together the shell halves. FWIW, they do make digital cassette with
screw assemblies.
And yes, as you've discovered, digital cassette tape is the same width
as audio casette tape. The differences are in the oxide formulation.
Digital casette tape needs little in the way of frequency response,
and the response curve should be as flat as possible, whereas (IIRC)
audio casette tape tends to bump up the low and high ends.
Also, digital tape needs a very low dropout rate, so they end up
with a more uniform oxide coating. And, I've never seen them use
metal or chromium dioxide for digital cassettes. Lastly, the
substrate needs not to stretch, so long tape lengths are out.
regards,
-dq
In a message dated 7/31/00 4:21:30 PM Eastern Daylight Time,
pechter(a)pechter.dyndns.org writes:
> Folks --
>
> This may be off topic -- but I'm looking for a power adapter
> IBM P/N 85G6670 (IBM Field Service FRU 85G6689) for an IBM 755CSD
> laptop.
>
> Does anyone have a source?
dont have one to spare, but a power supply from a 360 and any 750 or 755
series will also work for you.
DB Young ICQ: 29427634
hurry, hurry, step right up! see the computers you used as a kid!
-> www.nothingtodo.org
Does anyone know how to change the SCSI id settings on a HP 9 track
tapedrive model 7980 S? It's current setting is 3 but that is
conflicting with my disk. There is no thumbwheel and there are
no visible jumpers to find.
Thanks,
Ed
--
The Wanderer | Geloof nooit een politicus!
wanderer(a)bos.nl | Europarlementariers: zakken-
http://www.bos.nl/homes/wanderer | vullers en dumpplaats voor
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Gates!
Hello,
I need a cross-reference for a part which Tony has identified
as a thermistor; it carries the printed designation
MCI
307138
and that's it. I found a company called Midwest Components
that makes a line of thermistors they call Thermodisc, but
after contacting them, they indicated that this was not a
part of theirs and might not be a thermistor.
As an alternative...
There is an undamaged one on the main board. If I remove it,
can someone suggest a way to determine its specifications
by use of a test circuit of some kind?
tia,
-doug quebbeman
> I was thinking (I could be wrong) that a scanner could take in the whole
> 4" x 5" microfilm sheet at once, and then I could write some software that
would
> parse the whole-sheet image into frames, do some automatic cleanup on each
> individual frame, and compress. Am I walking down the wrong path?
Yes.
From: Sellam Ismail <foo(a)siconic.com>
Subject: Chieftain or Gimix?
There's two I'd kinda like to buy or swap time on... I have some TSC
software that might work fine on them. Were there derivitave OSes for
either of them?
One Cheiften passed by a long time ago on ebay and advertised a 68000
processor. Cool.
wow
- Mike: dogas(a)leading.net
On Jul 30, 18:37, Tony Duell wrote:
> Has anyone ever seen a splicing jig and tape (or any other form of repair
> kit) for the tape cassettes (HP82176??) used in the HP82161 tape drive.
> I'm trying to read some old tapes and the magnetic tape on one of them
> has come unstuck from the leader. I think it would be possible to stick
> them together again.
How wide is the tape? If it's not too narrow, you could try 1/2" audio
splicing tape (thin self-adhesive mylar tape, usually white or yellow).
The technique is to butt the two ends together, tape over (the non-oxide
side!) with the adhesive tape at right angles to the tape, and trim with a
razor blade or fine scissors. For 1/4" or bigger magnetic tape, I usually
trim the join very slightly narrower than 1/4" to help prevent binding.
I've done this successfully on compact cassette tape (1/8"), microcassette
tape, and 1/2" magtape and VHS video tape -- the latter usually to put the
leader back on if it's snapped.
> No, I wouldn't trust the result for very long, but it might be good
> enough for me to recover the few files on said tape that I didn't manage
> to read before it broke...
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
* Assuming you're scanning old DEC fiche, might there be a way
* to reduce the cost by making the final electronic copies
* available for sale to others? It might also make sense to
* put the collection online and sell subscriptions or one-shot
* looks to view it. Or does Compaq refuse to allow
* redistribution of these old docs?
There certainly isn't any problem with distributing *existing* fiche.
The problem comes with new copies, especially when the copies get
distributed.
What I'd like to do, as a first step, is to take the fiche with all the
pocket service manuals and get those onto CD-R in some form. Then work
out a deal with DEC so I can give away those CD-R's just like I give
away PDP-10 and PDP-11 DECUS freeware CD's. I don't want to make any money off
this, and in fact I think it'd be wrong to make any money off it :-).
Tim.
