Somewhere I still have source for a PDP-11 bootloader I wrote back in the very early '80s. Managed to boot 2 or 3 different types of floppy and a HDD in a 256-w

Somewhere I still have source for a PDP-11 bootloader I wrote back in the very early '80s. Managed to boot 2 or 3 different types of floppy and a HDD in a 256-word ROM, complete with command line interface. I vague recall a trick where I happened to have 102 in a register (from loading the bus event interrupt vector) and a free shift gave me 204 which was a sector read command for the FDC - that got me a crucial extra word saving I needed, to shrink it from 257 words to 256.