initial work towards burst IEC protocol support

c64/kernal/iec_fast/burst_cia1_detect.s

@@ -0,0 +1,31 @@
+
+//
+// Helper routine for burst IEC protocol support
+//
+
+//
+// Based on idea by Pasi 'Albert' Ojala
+//
+
+
+#if CONFIG_IEC_BURST_CIA1
+
+
+burst_detect:
+
+#if CONFIG_IEC_JIFFYDOS || CONFIG_IEC_DOLPHINDOS
+
+	lda IECPROTO
+	bmi !+
+	bne burst_detect_fail              // skip if other protocol already detected
+!:
+#endif
+
+	panic #$FF // XXX implement this
+
+burst_detect_fail:
+
+	rts
+
+
+#endif

c64/kernal/iec_fast/burst_cia2_detect.s

@@ -0,0 +1,66 @@
+
+//
+// Helper routine for burst IEC protocol support
+//
+
+//
+// Based on idea by Pasi 'Albert' Ojala
+//
+
+
+#if CONFIG_IEC_BURST_CIA2
+
+
+burst_detect:
+
+#if CONFIG_IEC_JIFFYDOS || CONFIG_IEC_DOLPHINDOS
+
+	lda IECPROTO
+	bmi !+
+	bne burst_detect_fail              // skip if other protocol already detected
+!:
+#endif
+
+	// For extra safety, do it on disabled interupts
+	php
+	sei
+
+	// Set the clock rate to the fastest possible
+	ldy #$01
+	sty CIA2_TIMALO
+	dey
+	sty CIA2_TIMAHI
+
+	// Prepare registers for transfer
+	lda #$C1
+	sta CIA2_CRA                       // start timer A, serial out, TOD 50Hz
+	bit CIA2_ICR                       // clear interrupt register
+
+	// Send test byte
+	lda #$FF                           // $FF keeps DATA released, see https://www.c64-wiki.com/wiki/Fast_serial_bus_protocol
+	sta CIA2_SDR
+
+	// Wait until byte sent
+	lda #$08		                   // interrupt mask
+!:
+	bit CIA2_ICR                       
+	beq !-
+
+	// Now see if we get any byte back
+
+	lda CIA2_SDR    // XXX we do not need a value, we need to know if it was received
+
+
+	panic #$00      // XXX finish this routine
+	
+
+	plp
+
+	// FALLTROUGH
+
+burst_detect_fail:
+
+	rts
+
+
+#endif

c64/kernal/iec_fast/burst_soft_detect.s

@@ -0,0 +1,27 @@
+
+//
+// Helper routine for burst IEC protocol support
+//
+
+
+#if CONFIG_IEC_BURST_SOFT
+
+
+burst_detect:
+
+#if CONFIG_IEC_JIFFYDOS || CONFIG_IEC_DOLPHINDOS
+
+	lda IECPROTO
+	bmi !+
+	bne burst_detect_fail              // skip if other protocol already detected
+!:
+#endif
+
+	panic #$FF // XXX implement this
+
+burst_detect_fail:
+
+	rts
+
+
+#endif

c64/kernal/iec_fast/iec_fast_common.s

@@ -1,21 +0,0 @@
-
-//
-// Common routines for multiple IEC fact protocols
-//
-
-
-#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_fast/jiffydos_load.s

@@ -20,7 +20,7 @@ jiffydos_load:
 	// Timing is critical, do not allow interrupts
 	sei
 
-#if CONFIG_IEC_BLANK_SCREEN
+#if CONFIG_IEC_JIFFYDOS_BLANK
 
 	// Preserve register with screen status (blank/visibe)
 	lda VIC_SCROLY
@@ -57,7 +57,7 @@ jiffydos_load_loop:
 	lda CIA2_PRA
 	and #$FF - BIT_CIA2_PRA_DAT_OUT    // release
 
-#if CONFIG_IEC_BLANK_SCREEN
+#if CONFIG_IEC_JIFFYDOS_BLANK
 
 	// It seems JiffyDOS needs some time here; waste few cycles
 	nop
@@ -143,7 +143,7 @@ jiffydos_load_end:
 	lda #$01
 	sta IECPROTO
 
-#if CONFIG_IEC_BLANK_SCREEN
+#if CONFIG_IEC_JIFFYDOS_BLANK
 
 	// Restore screen state
 	lda TBTCNT