F18A Detection Improvements, Issue #649

The F18A detection had a side effect of triggering errant interrupts.  Should be resolved in this commit.

Author: wwarthen

Source/HBIOS/tms.asm

@@ -49,8 +49,8 @@
 ; Sprite Attributes:	$????	$????
 ; Unused:		$????	$????
 ;
-TMSCTRL1:       .EQU   1               ; CONTROL BITS
-TMSINTEN:       .EQU   5               ; INTERRUPT ENABLE BIT
+TMSCTRL1:	.EQU	1		; CONTROL BITS
+TMSINTEN:	.EQU	5		; INTERRUPT ENABLE BIT
 ;
 TMSKBD_NONE	.EQU	0
 TMSKBD_KBD	.EQU	1
@@ -269,9 +269,9 @@ TMS_PREINIT:
 	; DISABLE INTERRUPT GENERATION UNTIL AFTER INTERRUPT HANDLER
 	; HAS BEEN INSTALLED.
 	LD	A, (TMS_INITVDU_REG_1)
-        RES	TMSINTEN, A             ; RESET INTERRUPT ENABLE BIT
-	LD	(TMS_INITVDU_REG_1), A
-        LD	C, TMSCTRL1
+	RES	TMSINTEN, A		; RESET INTERRUPT ENABLE BIT
+	LD	(TMS_INITVDU_REG_1),A
+	LD	C, TMSCTRL1
 	JP	TMS_SET_X		; SET REG W/O INT MGMT
 ;
 TMS_INIT:
@@ -345,56 +345,20 @@ TMS_INIT1:
 	CALL PRTSTRD
 	.TEXT	" VDP=$"
 
+	HB_DI
 	CALL	TMS_GETTYP		; A <- 0: TMS9918A, 1: V9938, 2: V9958, 3: SUPER V9958, 4:F18A
 	LD	(TMS_ATTRIB),A		; SET VDP_ID IN LOW BYTE OF DEVICE ATTRIBUTES
+	HB_EI
 
-	PUSH	AF
-	CALL 	TMS_CRTINIT		; SETUP THE TMS/V99x8 CHIP REGISTERS
-					; THIS IS BEST DONE BEFORE DETECTION OF TYPE
-					; AND VRAM SIZE
-	POP	AF
-
-
-	INC	A
-	DEC	A
-	JR	NZ, TMS_NOT9918
-
-	CALL PRTSTRD
-	.TEXT	"TMS9918A$"
-	JR	TMS_INIT3
-
-TMS_NOT9918:
-	DEC	A
-	JR	NZ, TMS_NOT9938
-
-	CALL PRTSTRD
-	.TEXT	"V9938$"
-	JR	TMS_INIT2
-
-TMS_NOT9938:
-	DEC	A
-	JR	NZ, TMS_NOTV9958
+	; PRINT THE CHIP TYPE DETECTED
+	LD	DE,TMS_CHIPSTR
+	CALL	PRTIDXDEA
 
-	CALL PRTSTRD
-	.TEXT	"V9958$"
-	JR	TMS_INIT2
-
-TMS_NOTV9958:
-	DEC	A
-	JR	NZ, TMS_NOTSV9958
-	
-	CALL PRTSTRD
-	.TEXT	"SUPER V9958 VRAM=8MB$"
-	JR	TMS_INIT3
-	
-TMS_NOTSV9958:
-	; ASSUME F18A
-	CALL PRTSTRD
-	.TEXT	"F18A$"
-	JR	TMS_INIT3
-	
+	CALL 	TMS_CRTINIT		; SETUP THE TMS/V99x8 CHIP REGISTERS
 
 TMS_INIT2:
+	JR	TMS_INIT3		; SKIPPING THIS FOR NOW...
+
 	CALL PRTSTRD
 	.TEXT	" VRAM=$"
 
@@ -771,7 +735,7 @@ TMS_SET_X:
 ;
 TMS_WR:
 #IF (TMS80COLS)
-        ; CLEAR R#14 FOR V9958
+	; CLEAR R#14 FOR V9958
 	HB_DI
 	XOR	A
 	EZ80_IO
@@ -850,39 +814,42 @@ TMS_GETTYP:
 	; Code sourced from https://map.grauw.nl/sources/vdp_detection.php
 	CALL	TMS_IS9918 		; USE A DIFFERENT WAY TO DETECT TMS9918A
 	JR	Z,TMS_ISF18A		; IF TMS9918A CHECK FOR F18A VARIANT
+;
+	; NOT A 9918 OR F18A, SO USE VDP ID
 	LD	A,1			; SELECT S#1
 	EZ80_IO
 	OUT 	(TMS_CMDREG),A
 	LD 	A,15 + 128
 	EZ80_IO
 	OUT 	(TMS_CMDREG),A
 	EZ80_IO
-	IN	A,(TMS_CMDREG)          ; READ S#1
-	AND	00111110B        	; GET VDP ID
+	IN	A,(TMS_CMDREG)		; READ S#1
+	AND	00111110B		; GET VDP ID
 	RRCA				; 00000 - V9938 1
 					; 00010 - V9958 2
 					; 10010 - v9958 3
-
-	EX	AF,AF'
-	XOR	A			; RESTORE SELECT REGISTER TO S#0 FOR INT HANDLER
+;
+	; RESTORE SELECT REGISTER TO S#0 FOR INT HANDLER
+	PUSH	AF
+	XOR	A			
 	EZ80_IO
 	OUT	(TMS_CMDREG),A
 	LD	A,15 + 128
 	EZ80_IO
 	OUT	(TMS_CMDREG),A
-	EX	AF,AF'
-
+	POP	AF
+;
+	; RETURN THE IDENTIFIED CHIP ID
 	JR	Z, TMS_ISV9938
 	CP	2
 	RET	Z			; RETURN 2 FOR V9958
-
 	LD	A, 3
 	RET				; RETURN 3 FOR SUPER V9958
 
 TMS_ISV9938:
-	INC 	A                	; RETURN 1 FOR V9938
+	INC	A			; RETURN 1 FOR V9938
 	RET
-	
+
 TMS_ISF18A:
 	; CHECK FOR F18A FPGA/EMULATOR VARIANT
 	; THE VDP REGISTERS MUST BE (RE)INITIALIZED AFTER THE CHECK
@@ -901,6 +868,7 @@ TMS_ISF18A:
 	LD 	A,57 + 128		; REGISTER #57
 	EZ80_IO
 	OUT 	(TMS_CMDREG),A
+;
 	; GET VDP ID
 	LD	A,1			; SELECT S#1
 	EZ80_IO
@@ -909,26 +877,43 @@ TMS_ISF18A:
 	EZ80_IO
 	OUT 	(TMS_CMDREG),A
 	EZ80_IO
-	IN	A,(TMS_CMDREG)          ; READ S#1
-	AND	11110000B        	; MASK HIGH NIBBLE
+	IN	A,(TMS_CMDREG)		; READ S#1
+;
+	; CHECK FOR F18A
+	AND	11110000B		; MASK HIGH NIBBLE
 	CP	$E0			; IS IT A F18A?
-	LD	A,0			; SELECT S#0 / NOT F18A
-	PUSH	AF
+	JR	Z,TMS_ISF18A1		; HANDLE IT IF SO
+;
+	; ON A TRUE 9918, THE F18A UNLOCK CODE ABOVE WILL ENABLE
+	; INTERRUPTS (REGISTER 57 ON A REAL 9918 WILL BE TREATED
+	; AS REGISTER 1!).  HERE WE GET INTERRUPTS TURNED BACK OFF.
+	LD	A, (TMS_INITVDU_REG_1)
+	RES	TMSINTEN,A		; RESET INTERRUPT ENABLE BIT
+	LD	C, TMSCTRL1
+	CALL	TMS_SET_X		; SET REG W/O INT MGMT
+
+	; WE DON'T BOTHER TO RESET THE STATUS REGISTER SELECTION OR
+	; RELOCK BECAUSE THIS IS NOT AN F18A!
+	XOR	A			; CHIP ID FOR 9918A
+	RET				; NOT F18A: A=0
+	
+TMS_ISF18A1:
 	; RESTORE STATUS REGISTER S#0 FOR INT HANDLER
+	XOR	A			; SELECT S#0 / NOT F18A
 	EZ80_IO
 	OUT	(TMS_CMDREG),A
 	LD	A,15 + 128
 	EZ80_IO
 	OUT	(TMS_CMDREG),A
+;
 	; RELOCK THE F18A
 	XOR	A			; LOCK VALUE
 	EZ80_IO
 	OUT 	(TMS_CMDREG),A
 	LD 	A,57 + 128		; REGISTER #57
 	EZ80_IO
 	OUT 	(TMS_CMDREG),A
-	POP	AF
-	RET	NZ			; NOT F18A: A=0
+;
 	LD	A,4			; F18A: A=4
 	RET	
 	
@@ -946,15 +931,19 @@ TMS_ISF18A:
 ; F <- Z: TMS9918A, NZ: V99X8
 ;
 TMS_IS9918:
+	LD	C,TMS_CMDREG		; POINT TO CMD REG PORT
+;
+TMSIS9918_WAIT1:
 	EZ80_IO
-	IN	A,(TMS_CMDREG)		; READ S#0, MAKE SURE INTERRUPT FLAG (F) IS RESET
-
-TMS_IS9918_WAIT:
+	IN	A,(C)			; READ S#0, MAKE SURE INTERRUPT FLAG (F) IS RESET
+	JP	M,TMSIS9918_WAIT1	; LOOP UNTIL INT FLAG (F) IS RESET
+;
+TMS_IS9918_WAIT2:
 	EZ80_IO
-	IN	A,(TMS_CMDREG)		; READ S#0
-	AND	A			; WAIT UNTIL INTERRUPT FLAG (F) IS SET
-	JP	P,TMS_IS9918_WAIT
-
+	IN	A,(C)			; READ S#0
+	JP	P,TMS_IS9918_WAIT2	; WAIT UNTIL INTERRUPT FLAG (F) IS SET
+;
+	; READ VB STATUS
 	LD	A,2			; SELECT S#2 ON V9938
 	EZ80_IO
 	OUT	(TMS_CMDREG),A
@@ -963,16 +952,18 @@ TMS_IS9918_WAIT:
 	OUT	(TMS_CMDREG),A
 	EZ80_IO
 	IN	A,(TMS_CMDREG)		; READ S#2 / S#0
-
-	EX	AF,AF'
-	XOR 	A                	; RESTORE SELECT REGISTER TO S#0 FOR INT HANDLER
+;
+	; RESTORE SELECT REGISTER TO S#0 FOR INT HANDLER
+	PUSH	AF
+	XOR 	A
 	EZ80_IO
 	OUT	(TMS_CMDREG),A
 	LD	A,15 + 128
 	EZ80_IO
 	OUT	(TMS_CMDREG),A
-	EX	AF,AF'
-
+	POP	AF
+;
+	; SET ZF APPROPRIATELY AND RETURN
 	AND	01000000B		; CHECK IF BIT 6 WAS 0 (S#0 5S) OR 1 (S#2 VR)
 	RET
 
@@ -1540,6 +1531,13 @@ TMS_POS		.DW	0		; CURRENT DISPLAY POSITION
 TMS_CURSAV	.DB	0		; SAVES ORIGINAL CHARACTER UNDER CURSOR
 TMS_BUF		.FILL	256,0		; COPY BUFFER
 ;
+TMS_CHIPSTR:
+TMS_STR9918	.TEXT	"TMS9918A$"
+TMS_STR9938	.TEXT	"V9938$"
+TMS_STR9958	.TEXT	"V9958$"
+TMS_STR9958X	.TEXT	"SUPER V9958$"
+TMS_STRF18A	.TEXT	"F18A$"
+;
 ; ### JLC Mod
 ; ANSI-->TMS Color Conversion Table
 TMS_COLOR_TBL	.DB	$01,$08,$02,$0A,$04,$06,$0C,$0F,$0E,$09,$03,$0B,$05,$0D,$07,$0F