started work on optimized LOAD loop for DolphinDOS

c64/kernal/iec/iec_rx_byte.s

@@ -30,30 +30,8 @@ iec_rx_byte:
 	// Wait till data line is released (someone else might be holding it)
 	jsr iec_wait_for_data_release
 
-	// Wait for talker to pull CLK.
+	// Check if EOI
-	// If over 200 usec (205 cycles on NTSC machine) , then it is EOI.
+	jsr iec_rx_check_eoi
-	// Loop iteraction takes 13 cycles, 17 full iterations are enough
-
-	ldx #$11                // 2 cycles
-iec_rx_clk_wait1:
-	lda CIA2_PRA            // 4 cycles
-	rol                     // 2 cycles, to put CLK in as the last bit
-	bpl iec_rx_not_eoi      // 2 cycles if not jumped
-	dex                     // 2 cycles
-    bne iec_rx_clk_wait1    // 3 cycles if jumped
-    
-	// Timeout - either this is the last byte of stream, or the stream is empty at all.
-	// Mark end of stream in IOSTATUS
-	jsr kernalstatus_EOI
-
-iec_rx_not_empty:
-
-	// Pull data for 60 usec to confirm it
-	jsr iec_release_clk_pull_data
-	jsr iec_wait60us
-	jsr iec_release_clk_data
-
-iec_rx_not_eoi:
 
 #if CONFIG_IEC_DOLPHINDOS
 

c64/kernal/iec/iec_rx_check_eoi.s

@@ -0,0 +1,32 @@
+
+//
+// Helper routine to check for EOI while receiving byte from IEC
+//
+
+iec_rx_check_eoi:
+
+	// Wait for talker to pull CLK.
+	// If over 200 usec (205 cycles on NTSC machine) , then it is EOI.
+	// Loop iteraction takes 13 cycles, 17 full iterations are enough
+
+	ldx #$11                           // 2 cycles
+
+!:
+	lda CIA2_PRA                       // 4 cycles
+	rol                                // 2 cycles, to put CLK in as the last bit
+	bpl iec_rx_check_eoi_done          // 2 cycles if not jumped
+	dex                                // 2 cycles
+    bne !-                             // 3 cycles if jumped
+    
+	// Timeout - either this is the last byte of stream, or the stream is empty at all.
+	// Mark end of stream in IOSTATUS
+	jsr kernalstatus_EOI
+
+	// Pull data for 60 usec to confirm it
+	jsr iec_release_clk_pull_data
+	jsr iec_wait60us
+	jsr iec_release_clk_data
+
+iec_rx_check_eoi_done:
+
+	rts

c64/kernal/iec/load_iec.s

@@ -99,12 +99,18 @@ load_iec:
 
 	lda VERCKK
 	bne load_iec_loop                  // branch if VERIFY
-
 	lda IECPROTO
-	cmp #$01
-	bne load_iec_loop                  // branch if not JiffyDOS
 
-	jmp load_jiffydos
+#if CONFIG_IEC_JIFFYDOS
+	cmp #$01
+	beq_far load_jiffydos              // branch if JiffyDOS
+#endif
+
+#if CONFIG_IEC_DOLPHINDOS
+	// XXX enable when finished
+	// cmp #$02
+	// beq_far load_dolphindos            // branch if JiffyDOS
+#endif
 
 #endif
 

c64/kernal/iec_fast/dolphindos_detect.s

@@ -54,6 +54,8 @@ dolphindos_detect_loop:
 
 dolphindos_detect_fail:
 
+	panic #$00
+
 	rts
 
 dolphindos_detect_success:

c64/kernal/iec_fast/load_dolphindos.s

@@ -0,0 +1,27 @@
+
+//
+// DolphinDOS protocol support for IEC - optimized load loop
+//
+
+
+#if CONFIG_IEC_DOLPHINDOS && !CONFIG_MEMORY_MODEL_60K
+
+
+load_dolphindos:
+
+	// Timing is critical for some parts, do not allow interrupts
+	sei
+
+	// A trick to shorten EAL update time
+	ldy #$FF
+
+	// FALLTROUGH
+
+load_dolphindos_loop:
+
+
+
+	panic #$00 // XXX this routine is not finished yet
+
+
+#endif // CONFIG_IEC_DOLPHINDOS and not CONFIG_MEMORY_MODEL_60K