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Punching Object Decks
from ROPE output to "our" IBM 026

The goal of this page is to give instructions to take:
    - an "object" file from the ROPE simulater (
    - automatically convert the characters from ASCII to BCD hole punches
    - and punch the holes into cards in "our" specially wired IBM 026
so you may take this real "object deck" to run on "our" IBM 1401 machines.

Table of Contents:

Punching object decks from ROPE to a keypunch - by Stan Paddock (Jan 17, 2008)

  • The Computer History Museum has one of the only operational IBM 1401 computers left in the world.

  • While the 1401 has the maximum 16,000 BCD characters of memory, we don't have any native program development software. The most popular tool was called Autocoder.

  • Between Ronald Mak and Van Snyder, a version of Autocoder and a 1401 simulator was written for the IBM PC. This system will generate card images on the IBM PC disk drive. Until now, these cards would have to be printed out and punched by hand on an IBM keypunch.

How It's Done

  • In order to control an IBM keypunch, there are 14 lines that need to be activated to cause the keypunch to punch data; 12 row punches, a space and a release. These wires were added to the wiring of an IBM 026 and wired to a bank or relays controlled by the IBM PC. Software written for the IBM PC will open a card image file and command the IBM 026 keypunch top punch the cards.

  • The interface to the keypunch is by relay contact only to protect both the keypunch and the PC. The wires are added in additional to the normal wires in the keypunch and in no way impact the normal functionality of the keypunch.
    [The interface unit, USB-SSR24 was built in Hungary, the vender is:
    Measurement Computing Corp.
    10 Commerce Way, Suite 1009
    Norton, MA USA 02766 " ]

How To Use The System

  • The IBM PC is located in the foyer leading to the main IBM 1401 restoration room. It is a normal PC running Windows XP.

  • There is a power master switch just under the monitor. Turn this on and press power on the front of the IBM PC.

  • Log on as a normal user (Ed's picture).
    - Hmmm, that is the nicest thing Stan has ever said about me -
    - I suppose I should try to say something nice about him -
    - Do little white lies count?
    -- Just kidding, of course, I think ...

  • The machine has two disk drives. If you don't already have a folder on the D: drive, use the windows explorer, and go to the D: drive and create a folder with your name. You may then create any sub-folders that you want.

  • There is an IBMROPE ICON on the screen that, when double-clicked, will bring up ROPE. You can develop, assemble and test your code from here.

  • There is an RmtPunch ICON on the screen that, when double-clicked, will bring up RmtPunch. This is the program that will send your data to the keypunch. The program will open with a screen asking you to select the file you want to punch. If the data is verified, you will be asked if you want to Punch or Exit.

  • If you are going to punch, put as many cards as required in the keypunch and feed/release at least 10 to insure the keypunch is warmed up. The "Auto Feed" switch must be on and it is suggested that the print switch be off. Before you enter Punch, empty the output stacker so the blank cards do not get confused with the punched cards. After you enter the "P", the keypunch will start.

  • If you need to stop the punching, press any key and the punching will pause at the end of the current card. This gives you an opportunity to add more cards to the input hopper.

  • If you have had a problem while punching, notice the count on the IBM PC monitor. You can re-start the program and skip the number of cards that punched correctly.

Troubles along the way from Stan Paddock, Feb 4, 2015,
Name changed to protect the innocent ;-))
XX used the 029 Keypunch in the Libert Room to punch the Christmas banner deck.
There were a few glitches punching the deck.
XX did not pull out the partial and blank cards from the punched deck.
The 1401 does not like trying to execute blanks cards.

The punch card equipment is pausing during punching with a communication error.
This can happen in the middle of a card.
If you clear the card punch, you can have that partial and a blank card fowling.
XX did not think about that.
The 1401 did tell me about it.
Note: Although there is no validity check punched into the card,
the last four columns (77, 78, 79, 80) are the sequence number, which is helpful.
If column 80 is blank, there was a problem punching this card, toss it.