commit 2632146

Add an example about UUID-based extension selection.

 1@@ -317,6 +317,15 @@ extension; this may be read-only, write-only, or some combination. If the
 2 extension is not implemented, then the emulator MUST ignore it and MUST NOT
 3 attempt to write anything here, and MUST NOT override any devices.
 4 
 5+An example of how to use this:
 6+
 7+  @load-ext1 ( -- success ) ;ext1 #02 DEO2 ;ext1/v LDA JMP2r
 8+  @ext1 03 d0 <uuid> &v 00
 9+
10+This example does not use any extra data, and selects an extension for
11+device #d0. The <uuid> must be replaced by the appropriate sixteen-byte
12+UUID for the extension being selected.
13+
14 
15 === Implemented extensions ===
16