initial DophinDOS byte TX, does not work yet

c64/kernal/iec/iec_cmd_open.s

@@ -17,8 +17,21 @@ iec_cmd_open: // similar to TKSA, but without turnaround
 !:
 	ora #$F0
 
+#if CONFIG_IEC_DOLPHINDOS
+/* XXX does not work yet
+	sta TBTCNT
+	jsr iec_tx_command
+	bcs !+ // branch if error
+
+	jsr dolphindos_detect
+	jmp iec_tx_command_finalize
+*/
+#else
+
 	// FALLTROUGH
 
+#endif
+
 common_open_close_unlsn_second: // common part of several commands
 
 	sta TBTCNT

c64/kernal/iec/iec_tx_byte.s

@@ -70,6 +70,29 @@ iec_tx_common:
 	jsr iec_pull_clk_release_data_oneshot
 	jsr iec_wait60us
 
+#if CONFIG_IEC_DOLPHINDOS
+
+	// Check if DolphinDOS was detected
+	lda IECPROTO
+	cmp #$02
+	bne iec_tx_no_dolphindos
+
+	// For DolphinDOS just push the byte to parallel port (set it to output first)
+	lda #$FF
+	sta CIA2_DDRB
+	lda TBTCNT
+	sta CIA2_PRB
+
+	// Release CLK to indicate data is now valid (we should not hold DATA nevertheless)
+	jsr iec_release_clk_data
+
+	// Finish the flow
+	jmp iec_tx_common_finalize
+
+iec_tx_no_dolphindos:
+
+#endif // CONFIG_IEC_DOLPHINDOS
+
 	// Now, we can start transmission of 8 bits of data
 	ldx #7
 
@@ -115,6 +138,10 @@ iec_tx_common_bit_is_sent:
 	dex
 	bpl iec_tx_common_sendbit
 
+	// FALLTROUGH
+
+iec_tx_common_finalize:
+
 	cli
 
 	// Give devices time to tell if they are busy by pulling DATA

c64/kernal/iec/save_iec.s

@@ -48,18 +48,18 @@ save_iec:
 	lda STAL+0
 	sta TBTCNT
 	clc
-#if CONFIG_IEC_JIFFYDOS || CONFIG_IEC_DOLPHINDOS
+#if CONFIG_IEC_JIFFYDOS
 	jsr iec_tx_dispatch
-#else // no turbo supported
+#else
 	jsr iec_tx_byte
 #endif
 
 	lda STAL+1
 	sta TBTCNT
 	clc
-#if CONFIG_IEC_JIFFYDOS || CONFIG_IEC_DOLPHINDOS
+#if CONFIG_IEC_JIFFYDOS
 	jsr iec_tx_dispatch
-#else // no turbo supported
+#else
 	jsr iec_tx_byte
 #endif
 
@@ -78,9 +78,9 @@ iec_save_loop:
 	// Send the byte
 	sta TBTCNT
 	clc
-#if CONFIG_IEC_JIFFYDOS || CONFIG_IEC_DOLPHINDOS
+#if CONFIG_IEC_JIFFYDOS
 	jsr iec_tx_dispatch
-#else // no turbo supported
+#else
 	jsr iec_tx_byte
 #endif