start of JiffyDOS LOAD protocol support

bin/README.md

@@ -16,7 +16,7 @@ Follow these rules, or bad things will happen!
 
 <br />
 
-For Ultimate 64 the following settinghs are recommended:
+For Ultimate 64 motherboard the following settings are recommended:
 
 * U64 Specific Settings -> Turbo Control -> U64 Turbo Registers
 

src/,,config_custom.s

@@ -39,12 +39,14 @@
 
 ;; #CONFIG# IEC                        YES
 ;; #CONFIG# IEC_DOLPHINDOS             YES
-;; #CONFIG# IEC_DOLPHINDOS_FAST        YES
+;; #CONFIG# IEC_DOLPHINDOS_FAST        NO
 ;; #CONFIG# IEC_JIFFYDOS               YES
 ;; #CONFIG# IEC_JIFFYDOS_BLANK         NO
 ;; #CONFIG# IEC_BURST_CIA1             NO        ; please keep disabled for now
 ;; #CONFIG# IEC_BURST_CIA2             NO        ; please keep disabled for now
  
+;; #CONFIG# IEC_JD_TEST                NO        ; temporary setting, for JiffyDOS development
+
 
 ; --- Tape deck configuration
 

src/kernal/iec_fast/jiffydos_load.s

@@ -19,6 +19,30 @@
 
 jiffydos_load:
 
+
+!ifdef CONFIG_IEC_JD_TEST {
+
+	; XXX test implementation, not ready yet
+
+	; Switch to optimized LOAD protocol
+	jsr UNTLK
+	lda FA
+	jsr TALK
+	bcs jiffydos_load_error
+	lda #$61
+	jsr TKSA
+
+	; XXX finish the implementation
+
+	rts
+
+jiffydos_load_error:
+	
+	; XXX finish the implementation
+
+
+} else {
+
 	; XXX implement JiffyDOS optimized LOAD protocol, this one is ineffective
 
 
@@ -53,7 +77,7 @@ jiffydos_load:
 	; Blank screen to make sure no sprite/badline will interrupt
 	jsr screen_off
 @2:
-	; Preserve 3 lowest bits of CIA2_PRA  XXX deduplicate this
+	; Preserve 3 lowest bits of CIA2_PRA
 	jsr jiffydos_preserve_bits
 
 } else {
@@ -207,3 +231,5 @@ jiffydos_load_end:
 
 
 } } ; CONFIG_IEC_JIFFYDOS and not CONFIG_MEMORY_MODEL_60K
+
+}