On 10/21/05, charlesmorris at direcway.com <charlesmorris at direcway.com> wrote: In the case of the gear from the 1970s, OS/8 was rather expected. You _can_ do all sorts of stuff with paper tape (using a modern machine to emulate it), but for machine with block-addressable storage (DECtape, floppy, hard disk), OS/8 was by far and away the most popular. You may or may not have an RL boot PROM in your KM8AA, but if you don't, you can always key in the RL bootstrap by hand. Generally speaking, yes. The changes to the instruction set are minor and meant to be additive, but a really clever 8/i programmer can trip you up. There's a reason FOCAL does some probes to determine CPU type. Dunno about TSS/8 on an RL (probably no driver for anything newer than an RF08), but certainly OS/8. One caveat - there is a different driver for the RL01 and for the RL02. I myself have never used an RL02 on an 8/a. An expensive configuration for a DECmate I was an RL02, so I'm sure OS/78 supports it, but you might have to cherry-pick your OS/8 version to go with a larger disk. -ethan