Someone should add the equivalent of Ersatz-11's 'DOS' device to SIMH; it's a pseudo-device that can read files on the host filesystem. (Other stuff too, but that's the relevant one here.) A short device driver in the emulated OS, and a program to talk to it, and voila, getting a file into the emulated system is a short one line command, none of this hassle with putting the bits on a virtual tape, etc, etc. I found editing files with 'ed' on my simulated V6 system painful (although i still have the mental microcode to do it), so I did my editing under Windows (Epsilon), and then read the file down to the Unix to compile it. Initially I was doing it by putting the file on a raw virtual pack, and doing something similar to that tape kludge. Then I got smart, and whipped up a driver for the DOS device in Ersatz-11, and a program that used it, to allow me to easily read a file from the Windows filesystem down to the Unix. Going around the compile-debug-edit loop is totally painless now. Noel