This receipt is the result of the lower bit being stuck on the printer. Every character has an 8-bit binary code representing the letter. The lowest bit is stuck to 1, therefore it shifts any letter that doesn’t end in a 1 to the next character.
For example, EGG MCMUFFIN becomes EGG!MCMUGGIO because the exclamation point is one bit more than a space, the G is one bit higher than the F, and the O is one bit higher than the N. The ASCII binary representing the characters E, G, M, C, U, and I all end in 1, so they’re unaffected by the lower bit being stuck.
I made this fiddle to demonstrate the effect. Put any text you want into the input field and click BIT STUCK, it will generate the same effect as the receipt.
