instrument to debug loading.

c64/kernal/iec_rx_byte.s

@@ -5,13 +5,19 @@
 
 iec_rx_byte:
 
+	inc $062f
+	
 	;; First, we wait for the talker to release the CLK line.
 	jsr iec_wait_for_clock_release
 
+	inc $0630
+	
 	;; We then release the data line
 	;; (We can use this routine, since we weren't holding CLK, anyway)
 	jsr iec_release_clk_and_data
 
+	inc $0631
+	
 	;; Wait for talker to assert CLK.
 	;; If >200usec, then it is EOI and we have to assert the
 	;; DATA line for 60 usec to tell the TALKER that we have
@@ -24,6 +30,8 @@ iec_rx_clk_wait:
 	dex
 	bpl iec_rx_clk_wait
 
+	inc $0632
+	
 	;; EOI timeout: So pulse DATA line for 60 usec
 	jsr iec_assert_data
 	jsr iec_wait60us
@@ -38,6 +46,9 @@ iec_rx_clk_wait:
 	jmp iec_rx_clk_wait
 
 *
+	inc $0633
+
+	
 	;; CLK is now low.  Latch input bits in on rising edge
 	;; of CLK, eight times for eight bits.
 	ldx #7
@@ -46,8 +57,14 @@ iec_rx_clk_wait:
 	php
 	
 iec_rx_bit_loop:
+
+	inc $0634
+	
 	;; Wait for CLK to release
 	jsr iec_wait_for_clock_release
+
+	inc $0635
+	
 	;; DATA now has the next bit, but inverted.
 	;; DATA is in bit6, which is a bit annoying.
 	;; But we can clock it out with two ROL instructions
@@ -66,10 +83,14 @@ iec_rx_bit_loop:
 	;; Wait for CLK to re-assert
 	jsr iec_wait_for_clock_assert
 
+	inc $0636
+	
 	;; More bits?
 	dex
 	bpl iec_rx_bit_loop
 
+	inc $0637
+	
 	;; Then we must within 1000usec acknowledge the frame by
 	;; asserting DATA. At this point, CLK is asserted by the
 	;; talker and DATA by us, i.e., we are ready to receive