CTC & CPU Speed

- Revamped CTC detection algorithm hoping to handle problem XRBR is having
- Fixed typo in dynamic CPU speed test that caused it to not be properly recorded/reported (credit XRBR)
- Allow use of DEL/RUBOUT keys as backspace in ROM Loader and Debug Monitor

Source/HBIOS/ctc.asm

@@ -147,18 +147,16 @@ CTCTIVT		.EQU	INT_CTC0A + CTCTIMCH
 ;==================================================================================================
 ;
 CTC_PREINIT:
+	; BLINDLY RESET THE CTC ASSUMING IT IS THERE
+	LD	A,CTC_DEFCFG
+	OUT	(CTCBASE),A
+	OUT	(CTCBASE+1),A
+	OUT	(CTCBASE+2),A
+	OUT	(CTCBASE+3),A
+;
 	CALL	CTC_DETECT		; DO WE HAVE ONE?
 	LD	(CTC_EXIST),A		; SAVE IT
 	RET	NZ			; ABORT IF NONE
-;
-	; RESET ALL CTC CHANNELS
-	LD	B,4			; 4 CHANNELS
-	LD	C,CTCBASE		; FIRST CHANNEL PORT
-CTC_PREINIT1:
-	LD	A,CTC_DEFCFG		; CTC DEFAULT CONFIG
-	OUT	(C),A			; CTC COMMAND
-	INC	C			; NEXT CHANNEL PORT
-	DJNZ	CTC_PREINIT1
 ;
 #IF (CTCTIMER & (INTMODE == 2))
 	; SETUP TIMER INTERRUPT IVT SLOT
@@ -258,32 +256,33 @@ CTC_PRTCFG1:
 	RET
 ;
 ;==================================================================================================
-; DETECT CTC BY CHECKING REGISTER CAN BE WRITTEN AND READ, AND THEN BY SETTING UP ONE CHANNEL IN 
-; TIMER MODE AND CHECKING IT IS COUNTING DOWN.
+; DETECT CTC BY PROGRAMMING THE FIRST CHANNEL TO COUNT IN TIMER
+; MODE (BASED ON CPU CLOCK).  THEN CHECK IF COUNTER IS ACTUALLY
+; RUNNING.
 ;==================================================================================================
 ;
 CTC_DETECT:
-	LD	A,CTC_TIM256CFG
-	OUT	(CTCBASE),A
-	XOR	A
-	OUT	(CTCBASE),A
-	; CTC SHOULD NOW BE RUNNING WITH TIME CONSTANT 0
-	LD	A,CTC_TIM256CFG		; RESET
-	OUT	(CTCBASE),A
-	IN	A,(CTCBASE)		; SHOULD READ 0 NOW
-	CP	0
-	JR	NZ,CTC_NO
+	LD	A,CTC_TIM16CFG		; RESET & SETUP TIMER MODE
+	OUT	(CTCBASE),A		; SEND TO CTC
 	LD	A,$FF			; TIME CONSTANT $FF
-	OUT	(CTCBASE),A
-	IN	A,(CTCBASE)		; SHOULD NOT BE 0 NOW
-	CP	0
-	JR	Z,CTC_NO
-	XOR	A
-	RET
+	OUT	(CTCBASE),A		; SEND CONSTANT & START CTR
+	NOP				; BRIEF DELAY
+	IN	A,(CTCBASE)		; READ COUNTER
+	LD	C,A			; SAVE VALUE
+	CALL	DLY8			; WAIT A BIT
+	IN	A,(CTCBASE)		; READ COUNTER AGAIN
+	PUSH	AF			; SAVE RESULT
+	LD	A,CTC_DEFCFG		; DEFAULT CHANNEL CFG
+	OUT	(CTCBASE),A		; RESTORE TO DEFAULTS
+	POP	AF			; GET RESULT BACK
+	CP	C			; COMPARE TO PREVIOUS
+	JR	Z,CTC_NO		; IF SAME, FAIL
+	XOR	A			; SIGNAL SUCCESS
+	RET				; AND DONE
 CTC_NO:
-	OR	$FF
-	RET
+	OR	$FF			; SIGNAL FAILURE
+	RET				; AND DONE
 ;
+; CTC DRIVER DATA STORAGE
 ;
-;
-CTC_EXIST	.DB	$FF	
+CTC_EXIST	.DB	$FF		; SET TO ZERO IF EXISTS

Source/HBIOS/dbgmon.asm

@@ -878,6 +878,8 @@ GETLNLOP:
 	JR	Z,GETLNDONE		; YES, EXIT
 	CP	CHR_BS			; IS <BS>?
 	JR	Z,GETLNBS		; IF SO, HANDLE IT
+	CP	CHR_DEL			; IS <DEL>?
+	JR	Z,GETLNBS		; IF SO, HANDLE AS <BS>
 	CP	' '			; UNEXPECTED CONTROL CHAR?
 	JR	C,GETLNLOP		; IF SO, IGNORE IT AND GET NEXT
 	LD	B,A			; SAVE CHAR IN B FOR NOW
@@ -1854,6 +1856,7 @@ CHR_CR		.EQU	0DH
 CHR_LF		.EQU	0AH
 CHR_BS		.EQU	08H
 CHR_ESC		.EQU	1BH
+CHR_DEL		.EQU	7FH
 ;
 ;__________________________________________________________________________________________________
 ;

Source/HBIOS/hbios.asm

@@ -1898,8 +1898,8 @@ HB_CPU1:
 ;
 ; INIT OSCILLATOR SPEED FROM CONFIG
 ;
-	LD	HL,CPUOSC / 1000
-	LD	(HB_CPUOSC),HL
+	LD	HL,CPUOSC / 1000	; OSC SPD IN KHZ
+	LD	(HB_CPUOSC),HL		; INIT HB_CPUOSC DEFAULT
 ;
 ; ATTEMPT DYNAMIC CPU SPEED DERIVATION
 ; NOTE THAT FOR PLATFORMS WITH SOFTWARE SELECTABLE CPU SPEED,
@@ -1907,8 +1907,8 @@ HB_CPU1:
 ; POSSIBLE SETTING.  THE FINAL CPU SPEED WILL BE ADJUSTED
 ; LATER.
 ;
-	CALL	HB_CPUSPD		; CPU SPEED DETECTION
-	JR	NZ,HB_CPUSPD2		; SKIP IF FAILED
+	CALL	HB_CPUSPD		; DYNAMIC CPU SPEED DETECTION
+	JR	NZ,HB_CPUSPD2		; SKIP AHEAD IF FAILED
 ;
 ; RECORD THE UPDATED CPU OSCILLATOR SPEED
 ;
@@ -1917,8 +1917,9 @@ HB_CPU1:
 	; SO RECORD DOUBLE THE MEASURED VALUE
 	SLA	L
 	RL	H
-	LD	(HB_CPUOSC),HL
 #ENDIF
+;
+	LD	(HB_CPUOSC),HL		; RECORD MEASURED SPEED
 ;
 HB_CPUSPD2:
 ;

Source/HBIOS/romldr.asm

@@ -41,6 +41,7 @@ bel	.equ	7	; ASCII bell
 bs	.equ	8	; ASCII backspace
 lf	.equ	10	; ASCII linefeed
 cr	.equ	13	; ASCII carriage return
+del	.equ	127	; ASCII del/rubout
 ;
 cmdbuf	.equ	$80	; cmd buf is in second half of page zero
 cmdmax	.equ	60	; max cmd len (arbitrary), must be < bufsiz
@@ -1281,6 +1282,8 @@ rdln_nxt:
 	call	cin			; get a character
 	cp	bs			; backspace?
 	jr	z,rdln_bs		; handle it if so
+	cp	del			; del/rubout?
+	jr	z,rdln_bs		; handle as backspace
 	cp	cr			; return?
 	jr	z,rdln_cr		; handle it if so
 ;

Source/ver.inc

@@ -2,7 +2,7 @@
 #DEFINE	RMN	2
 #DEFINE	RUP	1
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.2.1-dev.1"
+#DEFINE BIOSVER	"3.2.1-dev.2"
 #define rmj	RMJ
 #define rmn	RMN
 #define rup	RUP

Source/ver.lib

@@ -3,5 +3,5 @@ rmn	equ	2
 rup	equ	1
 rtp	equ	0
 biosver	macro
-	db	"3.2.1-dev.1"
+	db	"3.2.1-dev.2"
 	endm