Creating a Christmas card on a vintage IBM 1401 mainframe
Deja vu! I spent years fixing mainframes at IBM and the 1403 lived on for years after the 1401, attached to more modern systems like System&#x2F;360.<p>It was quite a beast to maintain. The main part is a &quot;train&quot; of metal slugs with the letters, digits and a few symbols that hurtle around on a steel oiled track.<p>To print a letter H, the machine fires an electromagnet that drives a hammer onto the next H as it flies past.<p>One of the maintenance activities was adjusting the hammer strike, which you did by printing a page full of H&#x27;s, and moving the strike forwards and backwards so that the left and right uprights of the &quot;H&quot; were both printed clearly.<p>The worst scenario with this machine was a &quot;train crash&quot;, when one of the slugs dug into the train and all of the flying metal slugs smashed into each other in a giant screaming hail of destruction.<p>Other activities:
- topping up the hydraulic fluid
- replacing dead hammer drivers