More comments to top-level README.md

2016-03-20 22:17:04 +10:00
parent 91e2f4dd1a
commit 4a7752d637
1 changed files with 3 additions and 2 deletions
@@ -31,13 +31,14 @@ You will need [simh](http://simh.trailing-edge.com/) 4.0 to run pdp7-unix.  You

 `make pdp7`

-to run pdp-unix from the pdp7-unix source tree
+On 64-bit systems, you may need to set the C compiler's optimisation
+level to -O1. To run pdp-unix from the pdp7-unix source tree, do:

 `make run`

 Press `ctl-e` to break out the simulator into simh

-A typical pdp7-unix on simh looks like:
+A typical pdp7-unix session on simh looks like:

 <pre>
 pdp7 unixv0.simh