further work on new SCNKEY

c64/,,config_generic.s

@@ -58,7 +58,9 @@
 #define CONFIG_PANIC_SCREEN
 #define CONFIG_DOS_WEDGE
 #define CONFIG_BCD_SAFE_INTERRUPTS
-#define CONFIG_SCNKEY_TWW_CTR // for now has to be enabled
+// #define CONFIG_SCNKEY_TWW_CTR // XXX document this
+#define CONFIG_JOY1_CURSOR // XXX document this
+#define CONFIG_JOY2_CURSOR // XXX document this
 
 
 // Debug options

c64/,,config_mega65.s

@@ -60,7 +60,9 @@
 #define CONFIG_PANIC_SCREEN
 #define CONFIG_DOS_WEDGE
 #define CONFIG_BCD_SAFE_INTERRUPTS
-#define CONFIG_SCNKEY_TWW_CTR // for now has to be enabled
+#define CONFIG_SCNKEY_TWW_CTR // XXX document this
+#define CONFIG_JOY1_CURSOR // XXX document this
+#define CONFIG_JOY2_CURSOR // XXX document this
 
 
 // Debug options

c64/,,config_ultimate64.s

@@ -58,7 +58,9 @@
 #define CONFIG_PANIC_SCREEN
 #define CONFIG_DOS_WEDGE
 #define CONFIG_BCD_SAFE_INTERRUPTS
-#define CONFIG_SCNKEY_TWW_CTR // for now has to be enabled
+// #define CONFIG_SCNKEY_TWW_CTR // XXX document this
+#define CONFIG_JOY1_CURSOR // XXX document this
+#define CONFIG_JOY2_CURSOR // XXX document this
 
 
 // Debug options

c64/kernal/interrupts/udtim.s

@@ -25,18 +25,17 @@ udtim_update_stkey: // entry to be used when interrupts are disabled
 
 	// Another action we have to perform is to copy the last row of keyboard to RAM,
 	// so that various routines can detect the STOP key press
-	// XXX scnkey contains similar sequence - deduplicate this!
-	lda #$FF
-	sta CIA1_DDRA // output
-	lda #$00
-	sta CIA1_DDRB // input
 
 	lda #$7F
 	sta CIA1_PRA  // select the last row (bit to 0)
 
 	lda CIA1_PRB  // read the row
 	sta STKEY
-	rts
+
+	// Finish by disconnecting the keyboard, this will prevent
+	// interference when scanning joystick in port 1
+
+	jmp keyboard_disconnect
 
 udtim_clock_rollover:
 

c64/kernal/keyboard/kb_matrix_lookup.s

@@ -1,21 +1,23 @@
 
 //
-// Work out if normal, shifted, control or Vendor modified keyboard. 
-// Table contains the offsets into keyboard_matrixes that should be used
-// for different values of the bottom 3 bits of key_bucky_state XXX
-// Interaction is simple to work out when playing with a C64:
-// CTRL trumps SHIFT or VENDOR
-// VENDOR + SHIFT = DOES NOTHING
-// All 3 does CONTROL
+// Helper table for determining keyboard matrix decoding table on the C64 keyboard
 //
+// When more than one bucky keey is pressed, decoding keys is asking for trouble,
+// so never allow this.
+//
+
+
+#if !CONFIG_SCNKEY_TWW_CTR 
 
 kb_matrix_lookup:
 
-	.byte (__kb_matrix_normal - kb_matrix)  // Normal
-	.byte (__kb_matrix_shift  - kb_matrix)  // SHIFT
-	.byte (__kb_matrix_ctrl   - kb_matrix)  // CTRL
-	.byte (__kb_matrix_ctrl   - kb_matrix)  // CTRL + SHIFT
-	.byte (__kb_matrix_vendor - kb_matrix)  // VENDOR
-	.byte (__kb_matrix_vendor - kb_matrix)  // VENDOR + SHIFT
-	.byte (__kb_matrix_ctrl   - kb_matrix)  // VENDOR + CTRL
-	.byte (__kb_matrix_ctrl   - kb_matrix)  // VENDOR + CTRL + SHIFT
+	.byte (__kb_matrix_normal - kb_matrix)  // %000 Normal
+	.byte (__kb_matrix_shift  - kb_matrix)  // %001 SHIFT
+	.byte (__kb_matrix_vendor - kb_matrix)  // %010 VENDOR	
+	.byte $FF                               // %011 SHIFT+VENDOR
+	.byte (__kb_matrix_ctrl   - kb_matrix)  // %100 CTRL
+	.byte $FF                               // %101 SHIFT+CTRL
+	.byte $FF                               // %110 VENDOR+CTRL
+	.byte $FF                               // %111 SHIFT+VENDOR+CTRL
+
+#endif

c64/kernal/keyboard/kb_matrix_lookup_tww_ctr.s

@@ -0,0 +1,28 @@
+
+//
+// Work out if normal, shifted, control or Vendor modified keyboard. 
+// Table contains the offsets into keyboard_matrixes that should be used
+// for different values of the bottom 3 bits of key_bucky_state XXX
+// Interaction is simple to work out when playing with a C64:
+// CTRL trumps SHIFT or VENDOR
+// VENDOR + SHIFT = DOES NOTHING
+// All 3 does CONTROL
+//
+
+// This lookup table is used by TWW/CTR keyboard routine only!
+
+
+#if CONFIG_SCNKEY_TWW_CTR
+
+kb_matrix_lookup_tww_ctr:
+
+	.byte $00 		// Normal
+	.byte $40		// Shifted
+	.byte $80		// Control
+	.byte $80		// Control + SHIFT
+	.byte $C0		// Vendor
+	.byte $C0 		// Vendor + SHIFT
+	.byte $80		// Vendor + CTRL
+	.byte $80		// Vendor + CTRL + SHIFT
+
+#endif // CONFIG_SCNKEY_TWW_CTR

c64/kernal/keyboard/keyboard_disconnect.s

@@ -0,0 +1,12 @@
+
+//
+// Helper routine - disconnects the keyboard from CIA1_PRB,
+// leaves $FF in .X (behavior needed in some places)
+
+
+keyboard_disconnect:
+
+	ldx #$FF
+	stx CIA1_PRA  // disconnect all the rows
+
+	rts

c64/kernal/keyboard/scnkey.s

@@ -23,8 +23,9 @@
 
 // XXX add Commodore 128 keyboard support
 // XXX add Commodore 65 keybopard support
-// XXX add support for using joystick to move sursor keys
-// XXX explicitly prevent joystick port 1 interference
+// XXX add support for using joysticks to move cursor keys
+// XXX add support for keys which are repeated always
+
 
 #if !CONFIG_SCNKEY_TWW_CTR
 
@@ -46,7 +47,7 @@ SCNKEY:
 	// Check for any activity
 
 	lda #$00
-	sta CIA1_PRA  // connect all the rows
+	sta CIA1_PRA                   // connect all the rows
 	ldx #$FF
 	cpx CIA1_PRB
 	beq scnkey_no_keys
@@ -71,18 +72,44 @@ scnkey_bucky_loop:
 
 	jsr via_keylog // XXX for some CPUs we have indirect jsr
 
-	// Check if we have free space in the keyboard buffer
+	// Check if KEYTAB is not 0 (happens if more than one bucky key is pressed)
+	// High byte equal to 0 = table considered invalid
+	lda KEYTAB+1
+	beq scnkey_no_keys
 
-	lda NDX
-	cmp XMAX
-	bcs scnkey_no_keys             // no space in keyboard buffer - do not waste time
+#if CONFIG_JOY2_CURSOR
 
-	// XXX check for joystick activity
+	// XXX why this does not work???
+
+	// Check for control port 2 activity
+
+	// ldx #$00
+	// stx CIA1_DDRA                  // set port to input to read joystick
+
+	// lda CIA1_PRA                   // read the joystick 2 status
+
+	// dex
+	// stx CIA1_DDRA                  // set port back to output
+
+	// and #%00001111                 // filter out anything but joystick movement
+	// bne scnkey_joystick_a_filtered
+
+#endif
+
+	// Check for control port 1 activity (can interfere with keyboard)
+
+	jsr keyboard_disconnect        // disconnect all the rows, .X will be $FF
+	cpx CIA1_PRB                   // only control port activity will be reported
+#if CONFIG_JOY1_CURSOR
+	bne scnkey_joystick_x          // use joystick for cursor keys
+#else
+	bne scnkey_no_keys             // if activity detected do not scan the keyboard
+#endif
 
 	// Scan the keyboard matrix
 
+	ldy #$FF                       // offset in key matrix table, $FF for not found yet 
 	ldx #$07 // XXX adapt for C128 and C65 keyboards
-	ldy #$FF                       // offset in key matrix table, $FF for not found yet
 scnkey_matrix_loop:
 	lda kb_matrix_row_keys, x
 	sta CIA1_PRA
@@ -110,9 +137,16 @@ scnkey_matrix_loop_next:
 	dex
 	bpl scnkey_matrix_loop
 
-	// Scanning complete
+	// Scanning complete - check if we got a key
+
 	cpy #$FF
-	bne scnkey_got_key
+	beq scnkey_no_keys
+
+	// To be extra sure, check for possible control port 1 interference once again
+
+	jsr keyboard_disconnect        // disconnect all the rows, .X will be $FF
+	cpx CIA1_PRB                   // only control port activity will be reported
+	beq scnkey_got_key             // branch if joystick activity NOT detected
 
 	// FALLTROUGH
 
@@ -125,6 +159,25 @@ scnkey_no_keys:
 
 	rts
 
+#if CONFIG_JOY1_CURSOR || CONFIG_JOY2_CURSOR
+
+scnkey_joystick_x:
+
+	// Handle joystick activity (in .X) as cursor keys
+
+	txa
+	and #%00001111                 // filter out anything but movement
+
+	// FALLTROUGH
+
+scnkey_joystick_a_filtered:
+
+	// XXX finish the implementation
+
+	rts
+
+#endif
+
 scnkey_got_key: // .Y should now contain the key offset in matrix pointed by KEYTAB
 
 	cpy LSTX
@@ -148,6 +201,12 @@ scnkey_got_key: // .Y should now contain the key offset in matrix pointed by KEY
 
 scnkey_output_key:
 
+	// Check if we have free space in the keyboard buffer
+
+	lda NDX
+	cmp XMAX
+	bcs scnkey_early_repeat        // no space in buffer XXX set timer to trigger repeat the next time
+
 	// Reinitialize secondary counter
 
 	lda #$03
@@ -170,12 +229,10 @@ scnkey_handle_repeat:
 
 	// Check whether we should repeat keys
 
-	// XXX some keys should be repeat always!
-
 	lda RPTFLG
 	bpl scnkey_done                // branch if we should do no repeat
 
-	// First countdown (for the first repeat)
+	// Countdown before first repeat
 
 	lda DELAY
 	beq !+
@@ -183,7 +240,7 @@ scnkey_handle_repeat:
 
 	rts
 !:
-	// Second countdown (for both first and subsequential repeats)
+	// Countdown before subsequent repeats
 
 	lda KOUNT
 	beq scnkey_output_key          // if second counter is also 0, we can repeat the key
@@ -191,6 +248,17 @@ scnkey_handle_repeat:
 
 	rts
 
+scnkey_early_repeat:
+
+	// Keyboard buffer was full - at least make sure the key
+	// will be repeated as soon as possible
+
+	lda #$00
+	sta DELAY
+	sta KOUNT
+
+	rts
+
 via_keylog:
 	jmp (KEYLOG)
 

c64/kernal/keyboard/scnkey_set_keytab.s

@@ -5,8 +5,17 @@
 // - [CM64] Compute's Mapping the Commodore 64 - pages 220, 221
 //
 
+
 scnkey_set_keytab:
 
+
+#if CONFIG_SCNKEY_TWW_CTR // routine not compatible with legacy SCNKEY
+
+	rts
+
+#else
+
+
 	// Set initial KEYTAB value
 
 	lda #<kb_matrix
@@ -22,6 +31,16 @@ scnkey_set_keytab:
 
 	// Retrieve table offset
 	lda kb_matrix_lookup, x
+	cmp #$FF
+	bne scnkey_valid_offset
+
+	// $FF means we shouldn't decode anything, mark this by setting high byte
+	// of KEYTAB to 0 (I don't think anyone would put keyboard decoding table
+    // at zeropage)
+	lda #$00
+	beq !+ // branch always
+
+scnkey_valid_offset:
 
 	// Add offset to the vector
 	clc
@@ -29,8 +48,15 @@ scnkey_set_keytab:
 	sta KEYTAB+0
 	lda #$00
 	adc KEYTAB+1
+!:
 	sta KEYTAB+1
 
+	// FALLTROUGH
+
+
+#endif // no CONFIG_SCNKEY_TWW_CTR
+
+
 scnkey_toggle_if_needed: // entry for SCNKEY (TWW/CTR version)
 
 	// Check if we should toggle the character set

c64/kernal/keyboard/scnkey_tww_ctr.s

@@ -116,7 +116,7 @@ accept_key:
 	tax
 	pla
 	and #$3f
-	ora kb_matrix_lookup,x
+	ora kb_matrix_lookup_tww_ctr,x
 	tax
 	lda kb_matrix,x
 	// But don't insert $00 characters