initial work towards burst IEC protocol support

c64/kernal/iec/iec_cmd_open.s

@@ -17,13 +17,19 @@ iec_cmd_open: // similar to TKSA, but without turnaround
 !:
 	ora #$F0
 
-#if CONFIG_IEC_DOLPHINDOS
+#if CONFIG_IEC_DOLPHINDOS || CONFIG_IEC_BURST_CIA1 || CONFIG_IEC_BURST_CIA2 || CONFIG_IEC_BURST_SOFT
 
 	sta TBTCNT
 	jsr iec_tx_command
 	bcs !+ // branch if error
 
+#if CONFIG_IEC_DOLPHINDOS
 	jsr dolphindos_detect
+#endif
+#if CONFIG_IEC_BURST_CIA1 || CONFIG_IEC_BURST_CIA2 || CONFIG_IEC_BURST_SOFT
+	jsr burst_detect
+#endif
+
 	jmp iec_tx_command_finalize
 
 #else

c64/kernal/iec/iec_update_eal_by_y.s

@@ -0,0 +1,21 @@
+
+//
+// Common EAL update routine
+//
+
+
+#if (CONFIG_IEC_JIFFYDOS || CONFIG_IEC_DOLPHINDOS) && !CONFIG_MEMORY_MODEL_60K
+
+
+iec_update_EAL_by_Y: // note: Carry has to be set by caller!
+
+	tya
+	adc EAL+0
+	sta EAL+0
+	bcc !+
+	inc EAL+1
+!:
+	rts
+
+
+#endif

c64/kernal/iec/load_iec.s

@@ -63,9 +63,10 @@ load_iec:
 	bcs load_iec_error
 
 #if CONFIG_IEC_DOLPHINDOS
-
 	jsr dolphindos_detect
-
+#endif
+#if CONFIG_IEC_BURST_CIA1 || CONFIG_IEC_BURST_CIA2 || CONFIG_IEC_BURST_SOFT
+	jsr burst_detect
 #endif
 
 	// We are currently talker, so do the IEC turn around so that we

c64/kernal/iec/save_iec.s

@@ -45,9 +45,10 @@ save_iec:
 	bcs save_iec_dev_not_found
 
 #if CONFIG_IEC_DOLPHINDOS
-
 	jsr dolphindos_detect
-
+#endif
+#if CONFIG_IEC_BURST_CIA1 || CONFIG_IEC_BURST_CIA2 || CONFIG_IEC_BURST_SOFT
+	jsr burst_detect
 #endif
 
 	// Save start address