I'd love to write a program to "OCR" punched card images. Now, if
I only had some spare time. :-)
Scanners are cheap and ubiquitous. You could lay several cards on the
scanner at once, perhaps placing a specially-colored paper on the
normally white reflective lid, and presto - like chroma-key on video,
you can easily "see" the borders, index notch and holes. I wonder if
any of today's "paper port" auto-feeding cheapo scanners would handle
a punched card - I don't see why not.
It could save the card data in Jone's proposed file format. One advantage
of this system would be that it could handle aged cards that some physical
imperfection (like dents from rubber bands, folds, worn edges, etc.) that
might jam a card reader.
- John
Jefferson Computer Museum <http://www.threedee.com/jcm>
Don't write to me on this, write the the fellow below if this interests
anyone.
--------------------------------------------------------------------------
Cliff Boyer <homeline(a)ezl.com>
Alton, IL USA - Tuesday, April 21, 1998 at 00:11:30
I for got something a minute ago.
I found in a 2nd hand store a book that may be of some intrest.
It is titled "The IBM 5100 PORTABLE COMPUTER, A Comprehensive
Guide For Users and Programmers". Hard Bound, Published 1977.
Deals with BASIC & APL languages' and basic overview of computer.
Excellent condition.
I don't need it, so it's first come first served!
$5 would cover book & shipping!
--------------------------------------------------------------------
Russ Blakeman
RB Custom Services / Rt. 1 Box 62E / Harned, KY USA 40144
Phone: (502) 756-1749 Data/Fax:(502) 756-6991
Email: rhblake(a)bbtel.com or rhblake(a)bigfoot.com
Website: http://members.tripod.com/~RHBLAKE/
ICQ UIN #1714857
AOL Instant Messenger "RHBLAKEMAN"
* Parts/Service/Upgrades and more for MOST Computers*
--------------------------------------------------------------------
Wasn't there someone on here a while ago looking for 1702's? Whoever that
was, you might want to try Jameco(http://www.jameco.com), the catalog I
have shows them at $1.95 each, but I don't know how many they have left, if
any...
--------------------------------------------------------------
| http://members.tripod.com/~jrollins/index.html - Computers |
| http://www.geocities.com/Area51/Lair/1681/ - Star Trek |
| Orham(a)qth.net list admin KD7BCY
|
--------------------------------------------------------------
I have just got a Sun 2 clone workststion (Sun boards in an unbranded box)
and it won't boot.
If any one can decode the 'heartbeat' LEDs here is the code.
Looking down at the edge of the CPU board:
=============[Empty connector]=========[oxxx ooox]====================
where x is LED off and o is LED on.
I would like to mend this myself if possible. If it is going to require
component level diagnosis and repair then please bear in mind that I
haven't used a soldering iron or meter in anger since I was mending
televisions at school - when they all had 405 lines on the screen and
valves.
Regards
Pete
Tony Duell wrote:
> Punched cards have one major design bug IMHO that's not shared by paper
> tape. There's no 'column reference' on a card. On a tape, you can strobe
> off the sprocket track, but alas on a card a totally unpunched column is
> valid (=a space character).
>
> My Documation M200 uses the leading edge of the card as a reference. It
> then counts pulses from a toothed wheel/pickup head on the card roller
> shaft to deteremine where the columns should be.
>
> It's therefore almost impossible to make a hand-pulled card reader.
I rather liked Allison's long array of photodetectors (of whatever
flavour) to tell you where the leading edge is.
But why not have the same wheel to determine the position, but the card
turns the wheel rather than vice versa? You lose the non-contact
element of hand pulling, but you don't get motors chewing delicate
cards.
Philip.
-----Original Message-----
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Tuesday, 21 April 1998 12:27
Subject: Re: 5150
.
.
>It can be a little depressing to read a manual for a machine that you
>know you'll never own or even see (like the PDP6 schematics that I
>downloaded a couple of years ago). But I still think it's better than
>knowing nothing about the machine/
Thats why I keep my NeXT book!
On Apr 20, 14:06, Max Eskin wrote:
> Could someone tell me what the configuration of individual gates
> is (one of them, at least) for binary addition (or provide an EASY
> TO FIND reference)?
This sounds like a homework question... Well, I suppose all classic computers
have adders in them. You want to look up "half-adder" and "full-adder". A
half-adder adds two binary digits, to produce a sum output and a carry output.
A full adder is, not surprisingly, two half adders, wired so that it also has
a carry-in. You can make a half-adder from an XOR gate and an AND gate, though
that's not exactly how they're usually implemented. How to make a multi-bit
adder with look-ahead carry is left as an exercise for the reader :-)
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
<Boy I'd pay $100 for a working PDP11/23 with RL02's (at least one workin
<and bootable).
<
<Bill
get out a scrounge around. 11/23s are common as house flies. you should
be able to find one for free that is usable. The common problem is you
can find just the cpu box (cpu, ram, IO, maybe disk controller) but no
drives.
The thing is with RX02s for $100 is possible, with RL02s no way. RL02
drives used go for more than that alone. I'm looking for a RL02 drive
myself as I only have one, they are scarce and expensive.
SCSI boards and eithernet cards same thing, expensive. CPU boards, maybe
$20-40.
The problem is most cards compatable with an 11/23 are also compatable
with most of the qbus VAX systems other than memory(usable but far too
slow and limiting in other ways.).
Allison
