IBM 1401


IBM 1401 tribute to Apollo XI

To celebrate the 50th anniversary of the Apollo Moon landing, I make and run a program that prints an ASCII banner in homage to Apollo XI, as well as a reproduction of the first page of the Apollo Guidance Computer landing program P63 source code.

The project consists of a simple program that reads two pages worth of text from punched cards and prints them on the printer. Several wrinkles are added to this:

1- The printer line is 132 character wide but the punch cards are only 80 character wide. So each original ASCII art lines are broken into two consecutive cards, one with the first 80 characters and one with the last 52 characters.

2- To facilitate printing a lot of copies without having to re-read the deck of cards each time, all the data cards are first read into core memory and printed once. The program then halts. Any further press on the START button will start another print, this time reading the data directly from core memory. This limits the printout to only two pages with our (maxed out) 16 kW core memory system!

3- A card containing -EOF- will cause the printer to jump to the next page before continuing printing the content of the next cards

4- A card containing -END- will cause the program to stop reading any further cards and start printing the content it loaded in memory.

Source code:

Object deck:


ASCII data input cards decks:

Executable tape to punch the deck:

(note that this file uses Pierce A encoding to conform with our tape emulator convention)

IDE, Autocoder Compiler and IBM 1401 emulator to compile and run the project on a PC, Mac or Linux computer: