Work in progress, just beginning, as of April 8, 2010
Table of Contents
Overview of the ABC
- Overview of the ABC
- Proposed Computing Group and skills
- Operator's Panel
- KeyPunch
- (decimal) KeyPunch Data Format
- Possible Binary Data Format
- Possible Pivot Comparator, non-existent
- Gaussian Elimination Algorithm, Recipe, Sequence, ...
- Improved Gaussian Elimination Need ability to compare coefficients
Much helpful info available on the Iowa State ABC website http://www.scl.ameslab.gov/ABC/ABC.html
Much of the following is a selection from that web site.
Overview drawing
from http://www.scl.ameslab.gov/Projects/ABC/Progress.html
Front view -
from http://www.scl.ameslab.gov/Projects/ABC/Progress.htmlProposed Computing Group
The following major tasks could be performed by one or more people, depending ...
- ABC Customer Interface / Mathematician
- - advise customers of capabilities of machine and suitable problems
- - select an initial scaling factor
- - prepare customer equations for keypunching
- - - possibly suggest equation sequencing for increased accuracy ...
- - schedule work on machine
- - attempt to verify machine results, possible machine or operator error
- - return results to customer, and consult
- ABC Machine Operator
- - perform regular test program to help assure ABC functioning correctly
- - accept input equations from Customer Interface
- - keypunch input equations
- - ? pre convert decimal card(s) data to a single binary "card" ? for each equation
- - - this step reduces operating complexity and confusion
- - perform the machine operations using Gaussian Elimination phases
- - - needs to determine the relative absolute values of pivot points
- - - possible aid of "binary column comparator", to be specified
- - - - (which binary card of pair to load onto the KA drum)
- - - if machine overflow, rescale the two inputs and try again.
- - convert the obtained single unknown equations to decimal,
- - - and record values onto output work sheets
- - using a desk calculator, and the single unknown equation on the work sheets
- - - determine the decimal value of each unknown
- - give results, and comments, to Customer Interface
- ABC Machine Technician
- - perform regular test program to help assure ABC functioning correctly
- - using technical expertise, repair any faults.
Operator's Panel
Operator's Panel, The annotation overflows onto a second image
Image from Charles Shorb
Top Rows
Bottom RowsKeyPunch
The way, (or the only "reasonable" way?) to get starting data into the ABC is via punched "IBM Cards"
Here is an inexpensive Key Punch of the era. (maybe an IBM Type 011 Electric Key punch?) Photo source unknown -
Overview
Keyboard DetailKey Punch Data Format (decimal values, to be converted to binary)
The data format for decimal input to the ABC is a repeating pattern of 5 data fields - one column indication sign of the following numeric value, 0 is negative, blank is positive - 15 columns of decimal numbers
the above format repeated 5 times,5 fields of 16 columns each = 80 columns available in the card. Possible Binary Data Format
Possible Pivot Comparator, non-existent
To aid production speed and accuracy, I think we need an unmentioned operator aid. To aid the operator with the challenge of trying to compare the absolute magnitudes of the pivot coefficients described above, an unmentioned mechanical aid would seem useful.
The operator would place the two Binary Data Cards for the next machine processing into two optical reader holders, and set the Comparator to focus on the line number (pivot coefficient) of the next ABC machine processing.
These two lines of bit positions, some intact paper, some perforated by an arc, can be made visible to the operator adjacent to each other for easier viewing - using what ever smoke, mirrors and magnifications are necessary to cause this effect.
Since the bit positions are likely to be 1/8 inches apart, vertically and horizontally, some back lighting and magnification is likely to be useful.
If you have comments or suggestions, Send e-mail to Ed Thelen