Running a special program on our vintage IBM 1401 mainframe for the Apollo XI landing anniversary

I have written a special program on the IBM 1401 mainframe to celebrate the Apollo 11 landing 50th anniversary. Now we just need to punch the card deck and run it on our old behemoth of a mainframe. Which as you will see is more difficult than it sounds. Come and see it demoed at the Computer History Museum on Saturday, 20th, 2019!
Files of the ASCII art and the 1401 program are available at:

[rafflesmaos]

When in doubt... power cycle. Clearly a time honored tradition :D

[anotherriddle]

I am so happy your channel turned up in the recommended list a couple of months ago. One of the very best channels on this platform. I enjoy every second :)

[Joemama]

you know it's bad when the old guard pulls out their pocket knife.!

[paradiselost]

I remember that many kids my age in the 1960's Silicon Valley area had unlimited access to punchcards to play with or draw on.

[TheSonicfrog]

On reason those IBM punch cards often misfed was that they were manufactured to exacting specifications and had to be kept in temperature/humidity controlled environments to maintain those specs. Special rotary presses were designed by IBM to process specially prepared card stock, all of which was quite expensive, and for a time sales of punch cards accounted for 25% of IBM profits!

[RWBHere]

The first mainframe computer I had access to was an IBM 1401; a very expensive machine, with heavy monthly service costs. Those card punch/readers could be a nightmare, and didn't always read even very simple programs accurately, and that didn't give people a good introduction to computing (it killed my interest in programming). When they worked, we thought that they were marvellous. How times have changed! You're very fortunate to have access to two '1401's that still work well, but to have hands-on experience with an AGC is a very rare privilege indeed. Thanks for the awesome video series Marc. It has been a pleasure, and very educational, to follow along with the project. A big 'Well done! Thank-you!' to all of the team.

[CursedLcie]

Excited for the video of you guys playing moon lander at MIT! I hope Margaret Hamilton and Don Eyles are there. I'm dying to know what all the programmers and engineers think of your work! I think you've all outdone yourselves. Great job!

[jfwfreo]

Its always good to see old hardware being used for what it was designed for.

[mitfreundlichengrussen]

so f...in awesome! I really enjoy watching the essence of computing and data handling. Rubber bands to secure your program/data stack of hundreds of punched cards, marking the stacks with lines, crosses and hints, manually feeding the bits to the machine, calling in a helping hand from a friend for a reset and boiling several Kw/h to print a line containing DIONYSIAN FLAG WAVING - BURNBABY!

[twinkytwinklier]

I like the fact that we programmers never change. We still write the best names and comments.

[davidbuckingham]

Well, that brings back some memories! In the days when computer engineers spent most of our time with Allen keys and feeler gauges in our pockets!

[jlwilliams]

Wow, watching you draw diagonal lines across your deck with a felt pen brings back lots of memories of doing the same thing during my first year of college! Not necessarily GOOD memories... lost my first and best college girlfriend because I was spending so much time in the computer lab trying to get my freshman COBOL project to run correctly )-;

[dr.strangelove]

Stay tuned for the next episode???
Marc ever since I saw your SC/MP computer and 1401 video, my interest in assembly language and electronics has amplified!! I am ALWAYS tuned for the next episode!!

[EdCali]

I owe my 40 year software engineering career to the IBM 1401. My high school had the foresight to utilize it for a computer class, including FORTRAN, since it was otherwise only operated on Fridays for district payroll runs. The advantage that jumpstart gave me in college was enormous and I soon became the "computer guy" to my fellow electrical engineers.

[Culturedropout]

"Looks like I picked a bad day to stop using hardware emulation..."

[cpt_nordbart]

I learned a new word today
"Cantankerous"

[_Hertz]

Seeing you play with the 1401 Mainframe reminds me of when I learned COBOL on an IBM System 32 (It was a desk-sized computer) with dual 8-inch floppy drives and ran on core-memory. We had IBM 26 card punchers and IBM 3741 floppy stations to enter the code. I really enjoyed the class and even got to play the sysop as I turned in my projects usually on the first day (we had a whole week to complete them).


Our instructor was a retired IBM tech who could fix the computer when it broke and even added a few upgrades.


Unfortunately, by the time I entered my first real job (Air Force), the IBM equipment was being replaced by newer, faster units, (usually mini-computers) and my hopes of getting into mainframe programming went the way of the Dodo bird.

[Shipwright]

I remember hearing from some of the older guys how they hated entering in programs on punch cards as the machines tended to be right curses to work with more often than not, I can see now they weren't exaggerating! Still, I think these old machines are amazing, thanks for sharing!

[wtmayhew]

The 1402 read/punch was a mechanical marvel. Back in 1976 my friends and I inherited 1402 from a bank that sent their 1401, 1403 and 72(?)K word core memory expander elsewhere. That seemed odd because the system power supplies are in the 1402. The 1402 weighs 1, 268 pounds! The rest of the system pretty much needs the 1402. Anyway, my recollection is the card weight makes a big difference. If I recollect right, you want to use the flat metal weight on the read side and the weight with the blue plastic handle on the punch side. Also the cards should be in good condition; too humid and the cards will jam. What is cool is the 1402 reads and punches cards broadside doing all 80 columns one row at a time. With the solar CB option, the 1402 could read 800 cards per minute and punch about 250 cards per minute. All I have left of the old 1402 is the unjamming crank handle which I saw being put to use in the video. Thanks for the memories!

[raqbit]

Yesterday I was happily able to obtain a print at the museum. Knew you made videos about the 1401, didn't watch this video before receiving the print. Thanks, it's a great souvenir :)