fixed byte sending (TX) via DolphinDOS

c64/kernal/iec/iec_cmd_open.s

@@ -18,14 +18,14 @@ 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

c64/kernal/iec/iec_rx_byte.s

@@ -129,7 +129,7 @@ iec_rx_clk_wait2:
 
 iec_rx_acknowledge:
 
-	// Then we must within 1000 usec acknowledge the frame by
+	// Then we must within 1000 usec acknowledge the byte by
 	// pulling DATA. At this point, CLK is pulled by the
 	// talker and DATA by us, i.e., we are ready to receive
 	// the next byte. (p11).

c64/kernal/iec/iec_tx_byte.s

@@ -64,12 +64,6 @@ iec_tx_common:
 	jsr iec_wait_for_data_pull
 	jsr iec_wait_for_data_release
 !:
-	// Pull CLK back to indicate that DATA is not valid, keep it for 60us
-	// We can use this routine as we don't hold DATA anyway (and its state doesn't even matter)
-
-	jsr iec_pull_clk_release_data_oneshot
-	jsr iec_wait60us
-
 #if CONFIG_IEC_DOLPHINDOS
 
 	// Check if DolphinDOS was detected
@@ -83,8 +77,8 @@ iec_tx_common:
 	lda TBTCNT
 	sta CIA2_PRB
 
-	// Release CLK to indicate data is now valid (we should not hold DATA nevertheless)
-	jsr iec_release_clk_data
+	// Pull CLK to indicate data is now valid (we should not hold DATA nevertheless)
+	jsr iec_pull_clk_release_data_oneshot
 
 	// Finish the flow
 	jmp iec_tx_common_finalize
@@ -93,6 +87,12 @@ iec_tx_no_dolphindos:
 
 #endif // CONFIG_IEC_DOLPHINDOS
 
+	// Pull CLK back to indicate that DATA is not valid, keep it for 60us
+	// We can use this routine as we don't hold DATA anyway (and its state doesn't even matter)
+
+	jsr iec_pull_clk_release_data_oneshot
+	jsr iec_wait60us
+
 	// Now, we can start transmission of 8 bits of data
 	ldx #7
 

c64/kernal/iec/save_iec.s

@@ -44,6 +44,12 @@ save_iec:
 	jsr iec_tx_command
 	bcs save_iec_dev_not_found
 
+#if CONFIG_IEC_DOLPHINDOS
+
+	jsr dolphindos_detect
+
+#endif
+
 	// Save start address
 	lda STAL+0
 	sta TBTCNT

c64/kernal/iec_fast/dolphindos_detect.s

@@ -43,8 +43,8 @@ dolphindos_detect:
 dolphindos_detect_loop:
 
 	lda CIA2_ICR
-	and #$10
-	bne dolphindos_detect_success
+	cmp #$10
+	beq dolphindos_detect_success
 	lda CIA2_PRB                       // XXX do we need this read?
 
 	dex