Loading software onto a real PDP11

On Thu, May 19, 2011 at 8:44 PM, Doug Jackson <doug at doughq.com> wrote: Nice. Good. As mentioned previously, there's vtserver (ftp://minnie.tuhs.org/pub/PDP-11/Vtserver/) - you would just need to hook your console line to a PC host and fire away, *but*, here's an important detail mentioned in the README file: "More specifically, I've used the Ersatz-11 2.0 demo simulator with various CPU models, and RL02 and RK05 disk images, to test copy. Here are the results: copy can read and write disk images for /24, /34A, /40, /44, /45, /70 and /94 systems when they have 256Kbytes of memory. It doesn't work for the 11/35 as it doesn't have the MUL instruction, which the 2.11BSD C compiler generates." The 11/04 maxes out at 56Kbytes (64K minus the I/O page). AFAIK, nobody has written a light-weight vtserver client, but I've thought about it more than once - it would be targeted to only have one client device driver at a time (unless there's room for RX and RL simultaneously), and wouldn't require 18-bit addressing, and if possible, would check for EIS and not use MUL if it wasn't available. Warren Toomey wrote the payload in C as the simplest course, and because his target environment was UNIX, his platform's resources far outstripped vtserver's needs. OTOH, there are plenty of completely useful PDP-11 configurations for DEC operating systems that do _not_ provide enough resources for vtserver as it stands today. One particular use I'd thought of for myself is to cobble up a lightweight client that could run on a PDT-11/150 to use it as an RX01 reader/writer for archiving boxes of floppies. Yes, there are other ways to read and write RX01s, but the next step up would be a smallish 11/03 or 11/04 and an RX02, and (because of the mixed density oddness) *those* have been more problematic to read and write. RXV11s are easier to find (IMO) than RXV21s, so a low-end RL01/RL02 archiver would also be of some use. -ethan