hook up unsupported error properly, add some comments

src/anti-m.a

@@ -92,8 +92,14 @@ Boot
          stx   $16FD                 ; hi byte of callback
          jmp   $1600
 @unknowncontroller
-         jmp   REBOOT
+         jmp   RebootImmediately
 
+Tracer
+         jsr   IDBroderbund
+         bcc   BeginTheBoot
+         jsr   IDSpiraDisc
+         bcc   BeginTheBoot
+; [execution falls through here]
 Unsupported
          lda   $C082
          jsr   TEXT
@@ -107,14 +113,7 @@ Unsupported
 RebootImmediately
          jmp   REBOOT
 
-Tracer
-         jsr   IDBroderbund
-         bcc   @jmpboot
-         jsr   IDSpiraDisc
-         bcc   @jmpboot
-         ;... others ...
-
-@jmpboot
+BeginTheBoot
          sec ;match boot-time flags and registers
          lda   #1
          ldy   #0

src/idbroderbund.a

@@ -1,3 +1,27 @@
+; Broderbund & Gebelli tracers
+; written by 4am
+;
+; tested on
+; - Choplifter (Broderbund)
+; - David's Midnight Magic (Broderbund)
+; - Dueling Digits (Broderbund)
+; - Genetic Drift (Broderbund)
+; - Labyrinth (Broderbund)
+; - Red Alert (Broderbund)
+; - Seafox (Broderbund)
+; - Serpentine (Broderbund)
+; - Sky Blazer (Broderbund)
+; - Space Quarks (Broderbund)
+; - Star Blazer (Broderbund)
+; - Eggs-It (Gebelli)
+; - High Orbit (Gebelli)
+; - Horizon V (Gebelli)
+; - Lazer Silk (Gebelli)
+; - Neptune (Gebelli)
+; - Phaser Fire (Gebelli)
+; - Russki Duck (Gebelli)
+; - Zenith (Gebelli)
+;
 IDBroderbund
 ; first stage is just a standard hybrid DOS 3.2/3.3 bootloader
          lda   #8

src/idspiradisc.a

@@ -1,13 +1,12 @@
-;-------------------------------
-; SpiraDisc support
+; SpiraDisc tracer
 ; written by qkumba
-; supports:
 ;
-; Frogger
-; Jawbreaker ][
-; Lunar Leepers
-; Pest Patrol
-
+; tested on
+; - Frogger
+; - Jawbreaker ][
+; - Lunar Leepers
+; - Pest Patrol
+;
 IDSpiraDisc
          lda   #8
          ldx   #1