One of my first summer intern jobs was recreating the boot deck for a PDP 8. The first card in the deck had become damaged and there was no backup. We had an old assembler listing of the boot program but no assembler. I did not know PDP assembly but knew 6502, Z80 and 370. I had done all my Z80 writing machine code directly as I had no assembler there either. So I read the PDP docs and hand assembled the first card. It was a relief when I found that the first instruction on the second card lined up as did the next several and the last instruction on the second card. We were pretty sure we had the right deck. I powered on the PDP, keyed the boot sequence, hit run and the deck loaded. The ready light came on and I loaded the next deck, the copy deck program. It loaded successfully as well and I reloaded the boot deck in to the card reader. Pressing the start button was a moment of suspense but when the card punch started clacking out a duplicate deck I was able to breathe a sigh of relief.

We had talked at lunch that day about making a special boot deck whose sole purpose would be to punch a replacement standard boot deck, but it seemed too ambitious for something rarely needed.

Asking a few years later, the boot deck had lasted until the machine had been retired. The backup deck had never been used