On 6/26/07, Dave McGuire <mcguire at neurotica.com> wrote: I was just reading some old list threads about PDP-8s and TU58s and emulators - transfer speed aside, the real problem was that most pre-OMNIBUS PDP-8s didn't have a spare serial port (just the console TTY), and that the serial hardware needs to be able to send a Break to the TU-58 to properly initialize and reset the controller in the TU-58, and unmodified PDP-8 hardware can't do that. I did run across a bunch of old 12-bit SIG newsletters from when the TU-58 was new, and all the gyrations folks went through to be able to use them, since at the time, they were about the cheapest mass storage you could get from DEC. One entire aspect of the project was how to mod M706/M707 or KL8E serial interfaces to generate a break. Another aspect was trying to wedge a driver into a couple of pages of code. If all PDP-8s had a spare serial port, it might make sense to have a serially-attached modern mass storage peripheral. Since that's nowhere near universal, it frequently comes down to deciding on which models to support. One of the few disadvantages of the PDP-8 spanning 1965 to 1994 (PDP-8 to DECmate III) is that there's a huge variety of hardware that all runs the same instruction set (give or take a couple instructions), but with an equally huge variety of default peripherals and expansion options. An RX01/RX02-attached device, at least, will work with OMNIBUS machines as well as the VT78 and DECmate I - overall not a bad range to cover. -ethan