X-Git-Url: http://cloudbase.mooo.com/gitweb/z180-stamp.git/blobdiff_plain/1ffa84bd778a4112b9e8e1cfb3de71108fb1a977..aea51b6c4c93c56715f50e64d424e1181c6d0242:/z180/cpuinfo.180

diff --git a/z180/cpuinfo.180 b/z180/cpuinfo.180
index 7d25dc2..0ea3e8e 100644
--- a/z180/cpuinfo.180
+++ b/z180/cpuinfo.180
@@ -30,52 +30,20 @@ base		equ	0
 done:	db	0
 result:	db	0
 
-;-------------------------------------------------------------------------------
-; Read internal register at address in L and IOBASE in H.
-;
-
-reg_in:
-	ld	a,h
-	add	a,l
-	ld	c,a
-	ld	b,0
-	in	a,(c)
-	ret
-
-;-------------------------------------------------------------------------------
-; Write internal register at address in L and IOBASE in H.
-;
-
-reg_out:
-	ld	b,a
-	ld	a,h
-	add	a,l
-	ld	c,a
-	ld	a,b
-	ld	b,0
-	out	(c),a
-	ret
-
 ;-------------------------------------------------------------------------------
 ; Check if register C exists. D holds mask of bit to test.
-;	return nz, if register exists
+;	return z, if register exists
 
 chk_reg:
-	call	reg_in
-	cp	0ffh
-	ret	nz		;
-
+	in	a,(c)
+	ld	l,a
 	; check, if register is changeable
-
-	xor	d		; set bit(s) in register to 0
-	call	reg_out
-	call	reg_in		; get it back
-	ex	af,af'
-	ld	a,0ffh		; set to register original state
-	call	reg_out
-	ex	af,af'
-	cpl
-	and	d
+	xor	d		;
+	out	(c),a
+	in	a,(c)		; get it back
+	xor	d
+	out	(c),l		; set register to original state
+	cp	l
 	ret
 
 ;-------------------------------------------------------------------------------
@@ -142,56 +110,47 @@ chk_z80:
 	; At least Hitachi HD64180
 	; Test differences in certain internal registers
 	; to determine the 180 variant.
-	; First, search the internal register bank.
-
-	ld	h,00H		; I/O Base
-find_base_loop:
-	ld	l,icr
-	call	reg_in
-	and	11011111b	; mask I/O Stop bit
-	xor	h
+
+	ld	b,0
+	ld	c,icr
+	in	a,(c)
 	cp	01FH
-	jr	nz,nxt_base
+	jr	z,icr_ok
 
 	;TODO: additional plausibility checks
 
-	jr	z,base_found
-nxt_base:
-	ld	a,h
-	add	a,040H
-	ld	h,a
-	jr	nc,find_base_loop
-	ret			;I/O registers not found
+	ret			; I/O registers not found
 
 	; Register (base) found.
 
-base_found:
+icr_ok:
 	inc	e		; HD64180
-	ld	l,RCR		; Disable Refresh Controller
-	xor	a		;
-	call	reg_out		;
-	ld	l,omcr		; Check, if CPU has OMCR register
+	out0	(RCR),b		;
+	ld	c,omcr		; Check, if CPU has OMCR register
 	ld	d,M_IOC		;
 	call	chk_reg		;
-	ret	z		; Register does not exist. It's a HD64180
+	ret	nz		; Register does not exist. It's a HD64180
 
 	inc	e		; Z80180
-	ld	l,cmr		; Check, if CPU has CMR register
+	ld	c,cmr		; Check, if CPU has CMR register
 	ld	d,M_LNC		;
 	call	chk_reg		;
-	ret	z		; register does not exist. It's a Z80180
+	ret	nz		; register does not exist. It's a Z80180
 
 	inc	e		; S180/L180 (class) detected.
-
 	ret
 
 ;-------------------------------------------------------------------------------
 
 start:
 	ld	sp,stack
+	ld	hl,done
+	ld	(hl),0
+	inc	hl
+	ld	(hl),0
+	push	hl
 	call	check
-
-	ld	hl,result
+	pop	hl
 	ld	(hl),e
 	dec	hl
 	ld	(hl),0ffH