SJ is the single-job monitor. One job is all you have, period. FB is the foreground-background monitor. You have two jobs. The foreground job is the higher-priority job. When it blocks, the background job gets a chance to run (actually, completion routines for the jobs are slightly higher than the jobs themselves). So, you can run a data collection program in the foreground, and the data reduction or storage program in the background. If you need to direct terminal input to the foreground, you type <Control-F> first, then type... To then have terminal input go to the background job, type <Control-B>. Later versions of RT-11 had foreground/background and up to 6 system jobs (with priorities in between background the foreground). Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+