From e1e9a6ed272f72cc1201d7ae62d59fdfbef233c6 Mon Sep 17 00:00:00 2001 From: Jeff Parsons Date: Thu, 20 Oct 2016 22:57:22 -0700 Subject: [PATCH] Minor Debugger improvements, notes, etc, while debugging the PDP-11 BASIC --- apps/pdp11/tapes/basic/README.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/apps/pdp11/tapes/basic/README.md b/apps/pdp11/tapes/basic/README.md index fb2d877e2..07c5237ba 100644 --- a/apps/pdp11/tapes/basic/README.md +++ b/apps/pdp11/tapes/basic/README.md @@ -23,9 +23,9 @@ Third-party resources include: Debugging Notes --------------- -One of the first things I noticed when debugging PDP-11 BASIC was its reliance on TRAP instructions. -For example, `TRAP 000` used to output the character in R2 to the terminal. Let's take a closer look at how its -TRAP handler works. +One of the first things I noticed when debugging PDP-11 BASIC was its heavy reliance on TRAP instructions. +For example, `TRAP 000` is used to output the character in R2 to the terminal. Let's take a closer look at how +its TRAP handler works. First, if you check the table of PDP-11 trap vectors, you'll see that the vector for TRAP instructions is 000034. So let's dump the contents of the two-word vector at 000034: