added comments

sources/exceptions.S

@@ -264,6 +264,8 @@ init_vec_loop:
   		move.l	a1,0xd8(a0)
  		lea		flpoow(pc),a1
   		move.l	a1,0xdc(a0)
+
+
 no_protect_vectors:
 		
 		// trap #0 (without any parameters for now) is used to provide BaS' XHDI
@@ -271,7 +273,7 @@ no_protect_vectors:
 		lea		_xhdi_sd_install,a1
 		move.l	a1,0x80(a0)				// trap #0 exception vector
 
-// int 1-7
+// ACP interrupts 1-7 (user-defined, generated by FPGA)
 		lea		irq1(pc),a1
 		move.l	a1,0x104(a0)
 		lea		irq2(pc),a1
@@ -286,12 +288,14 @@ no_protect_vectors:
 		move.l	a1,0x118(a0)
 		lea		irq7(pc),a1
 		move.l	a1,0x11c(a0)
-//psc_vectors
+// PSC vectors
 		lea		psc3(pc),a1
-		move.l	a1,0x180(a0)
-//timer 1 vectors
+		// PSC3 interrupt source = 32
+		move.l	a1,(32 + 64) * 4(a0)
+// timer vectors
 		lea		timer0(pc),a1
-		move.l	a1,0x1f8(a0)
+		// GPT0 interrupt source = 62
+		move.l	a1,(62 + 64) * 4(a0)
 
 		move.l	(sp)+,a2			// Restore registers
 		rts