ABC, Atanasoff Berry Computer, Looks Very Unusual
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Volunteer Information Exchange Sharing what we know with those we know Volume 4 Number 11 October 22, 2014 Contribute To The VIE What is an article about the Macon, that fantastic airship Lisa Exhibit Changed that once filled Hangar One at Moffet Field, doing in a newsletter about computer history? Well, it is not about DAG SPICER the Macon itself but about a model built by an IBM and Silicon Valley pioneer. Jack Clemmens made a career in storage starting with the original RAMAC. But when he retired, Jack started building his model with an eye toward flying it in Hangar One. The tie to computer history is loose but the story is fun. The ABC, Atanasoff Berry Computer, looks very unusual. It has few, if any, recognizable components. What is the input? Where is the output? What did it do? We've got many of the answers. Many Thanks to Alex Lux for keeping us in the loop on new acquisitions. (I love the Seymour Cray yearbook picture.) Several personnel changes are noted. We welcome Maya Makkar, new to the Education and Community Programs areas. Revolution keeps getting better. Dag tells us that a new, Herb Kanner reminded me to let you know that we older Lisa updates that display. have new artifact in place in Revolution. On October 12, CBS Sunday Morning did a feature on It is an original Apple Lisa I, and replaces the Lisa Walter Issacson's new book. The Innovators and the with 3.5” floppies that was there before. (The CHM was featured prominently. original Lisa used 5.25” “Twiggy” drives, as shown in Please remember, we are looking for your stories - the new object). especially that “first computer” or early computer experience. Jim Strickland [email protected] Contents Contribute to the VIE 1 1890 Venture Capitalist 1890 Venture Capitalist 1 Back in the day, IBM would commission films for its Lisa Exhibit Changed 1 100% Club and SE (Systems Engineer) Symposium events. They were played before “coffee breaks.” One The ABC – What's it all About? 2 of those was done by Bob Newhart and it's on New Assignment for William Harnack 3 YouTube. Links That You Might Enjoy 3 In the film, Bob receives a call from a Herman Hollerith, who tries to get support for his new invention to record A New Member Joins the Education Team 4 the 1890 U.S. census figures on punched cards. Macon Model Memorial to Jack Clemmens 4 The movie was found in 2003 on a 16 mm reel in the Recent Acquisitions 5 IBM Sweden library archives in Stockholm and showed at their 75th year anniversary the same year. Thus the Interesting Quotes 6 Swedish subtitles. CHN New Blog Entry 6 https://www.youtube.com/watch?v=pfskp4R53Q0 Coming Events 6 1 The ABC – What's It All About? To learn more about linear programming here are a few JIM STRICKLAND sites: We know that the ABC (Atanasoff Berry Computer) was General explanation: the "prior art" that invalidated the ENIAC/Univac patent. http://www.purplemath.com/modules/linprog.htm Also, Atanasoff's and Berry's stories are both worth Greater detail and a more formal explanation: telling. http://en.wikipedia.org/wiki/Linear_algebra But what did the ABC itself do? And how did it do what it Some examples: did? Looking at the artifact itself gives few clues. We can http://www.math.ncsu.edu/ma114/PDF/2.2.pdf see drums for memory and tubes for computation but Now, on to how the ABC worked. that really tells us little to answer those questions. This picture of our ABC reconstruction shows most of the What did the ABC do? important functional units of the machine. The team that did the reconstruction that resulted in our model felt that the ABC could really be called a general ABC Functions purpose computer. That may be a stretch but whether it 1. IBM Card Reader: reads standard punched cards. It could or not, it was definitely built to solve a particular set reads serially; the card does not move; the reading of problems, those of linear programming. brushes move one column at a time. Its output is to What is Linear Programming? the conversion drum. My personal experience with linear programming is very, 2. Decimal to Binary conversion drum: contains a “table” very limited. As an IBM Systems Engineer, I had a meat of conversions. That is, for each decimal number, its packing account which ran IBM supplied linear binary equivalent can be found. Its output is Drum 1, programming software on their 1401 to do sausage the keyboard drum. blending! 3. Computing circuits: 30 seven-tube add-subtract In moving to System /360 they had questions abut the 1401 compatibility feature which I was able to handle without ever learning anything about what that program really did, though I know that somehow it minimized cost based on what “hog parts” were being sold at what prices. In general, linear programming optimizes some output based on multiple constraints. Linear programming involves solving multiple linear equations, including inequalities, which contain multiple unknowns. The ABC does that by taking two linear equations at a time with up to 29 variables and a constant. Then it subtracts one equation from the other to eliminate one variable. Repeating this process, the machine eliminates one variable each iteration until the entire system of equations is solved. 2 circuits give it the capability of solving a linear • load a single sheet of paper to capture intermediate programming problem of 29 equations and 29 results and press a switch to cause it to be burned. unknowns. It handles two equations at a time, • load that intermediate output sheet of paper back in “subtracting” to eliminate one unknown (using a when required and press another switch. method called “ standard Gaussian elimination • read the final output from the "odometer" and note algorithm”). Each term can have up to 15 decimal whether the red light indicated a negative number. places. So, there is little of the sequential execution of an 4. Drums: 1,600 capacitors each. Each drum holds 30 algorithm that we associate with stored program numbers of 50 bits each. (Two of the columns are computers. It seems to me it is a stretch to say that the spares). The capacitors are recharged on each ABC has a program. revolution of the drums. To see the ABC do its thing, visit this “YouTube” of the 1) Input, intermediate results and output are stored on reconstruction team demonstrating it. the keyboard drum. https://www.youtube.com/watch?v=YyxGIbtMS9E 2) The counter drum is used during computation. The ABC is certainly not like anything that came before 3) Between the two larger drums is a smaller, timing or after after. But it: drum. • used electronics for calculation 5. Intermediate storage is required to solve problems • did calculation in binary with more than two equations, that is most of the • had memory problems that ABC is intended to solve. That intermediate storage is stiff sheets of heavy bond • was not analog paper. The paper sheets would be about 12 cm by 18 • did parallel processing cm (approximately 4.7” x 7”) and are not as thick as It was special. IBM cards. They are loaded individually. As they eject from the mechanism, they are apparently caught by New Assignment for William Harnack hand; there is no record of any kind of tray. JIM SOMERS 1) Binary Output Burner: burns (yes, burns!) tiny Over the next couple of weeks, you are likely to see holes in the sheets in binary. The sheet is moved William Harnack in locations you would not expect to see past pointed electrodes which burn holes through him. As of Monday, October 13th, William will be making the paper. the move from Collections to Front of House. After nine 2) Binary Input Reader: reads those sheets with holes years assisting with the maintenance and growth of the in binary that were previously output from the ABC. collection, William will, as a new Guest Services The card is moved past flat electrodes which read Coordinator, shift to a customer-focused role within Front the holes. of House. 6. “Odometer”: a set of engraved metal counters, the In this new role, William will be replacing Caroline Evans only decimal output. It must be reset and read and Poppy Haralson at the front desk on Mondays and manually. Tuesdays. He will be helping with phones, reception, 7. The operator panel: has a number of switches, a set shipping and receiving and all other front desk functions. of jumpers, a meter and lights. In addition to Mondays and Tuesdays, William will also 1) One switch turns on the drums. be serving as a ”floater,” providing desk coverage during 2) Two switches clear the two drums. evening rental events, assisting with lectures 3) Jumpers are manually adjusted to operate on each (registration, Q&A, book signings) and other Museum term of the equations. Events (NextGen, Community Days). 4) A particular red light indicates that the number on With his depth of knowledge of the collection and years the odometer is negative. of experience at the Museum, we are thrilled to have William join the FOH team. Please join me in welcoming The ABC is very, very operator oriented. Little happens William in his new role. without an operator causing it. For example, the operator Also, the FOH team (voices united in strains of “She’s a must: Jolly Good Fellow”) extends their thanks to Caroline and • toggle two switches to erase the two drums, clearing Poppy for their assistance at the front desk over the last memory.