X-Git-Url: http://cloudbase.mooo.com/gitweb/z180-stamp-cpm3.git/blobdiff_plain/40df51aed30ddcd710c7356f8098516c27088392..1e56f37617354c528443fc320e079037f1971ad9:/cbios/mm.180

diff --git a/cbios/mm.180 b/cbios/mm.180
index 9d1e256..d9efd16 100644
--- a/cbios/mm.180
+++ b/cbios/mm.180
@@ -3,20 +3,30 @@
 
 
 	global mmuinit
-	global bnk2log,bnk2phy,hwl2phy
+	global bnk2log,bnk2phy,hwl2phy,phy2log
 
 	include config.inc
 	include	z180reg.inc
 
 
 ;----------------------------------------------------------------------
-; Memory Map:
+; Memory Map 1:
 ;
-;	Common	CAStart ...     0FFFF
-;	Bank 0	  00000 ... CAStart-1
-;	Bank 1    10000 ...
+;	Common	CAStart ..     0FFFF
+;	Bank 0	  00000 .. CAStart-1
+;	Bank 1    10000 ..
 ;	Bank 2
 ;
+; Memory Map 2:
+;
+;	Common	  18000 .. 1BFFF	BANK1
+;
+;	Bank 0	  00000 .. 0BFFF	0
+;	Bank 1    0C000 .. 17FFF	1*BNK_SIZE
+;	Bank 2    1C000 .. 27FFF	2*BNK_SIZE + CMN_SIZE
+;	Bank 3    28000 .. 33FFF	3*BNK_SIZE + CMN_SIZE
+;	Bank n				n*BNK_SIZE + (n < 2) ? 0 : CMN_SIZE
+;
 ;----------------------------------------------------------------------
 
 	cseg
@@ -32,20 +42,55 @@ mmuinit:
 ; in  a: Bank number
 ; out a: bbr value
 
+   if 0	; Memory Map 1
+
 bnk2log:
 	or	a		;
 	ret	z		; Bank 0 is at physical address 0
 
-	dec	a
+	dec	a		;
 	push	bc		;
-	ld	b,a		;
-	ld	c,CA		;
+	ld	c,a		;
+	ld	b,BNK_SIZE	;
 	mlt	bc		; bank size * bank number
 	ld	a,c		;
 	add	a,10h		; add bank0 + common
 	pop	bc		;
 	ret			;
 
+   else ; Memory Map 2
+
+bnk2log:
+	or	a
+	ret	z		; Bank 0 is at physical address 0
+
+	push	bc
+	ld	c,a		;
+	ld	b,BNK_SIZE	;
+	mlt	bc		; bank size * bank number
+	cp	2		;
+	ld	a,c		;
+	pop	bc
+	ret	c
+	add	a,CMN_SIZE
+	ret
+
+    endif
+
+    if 0 ; table version
+
+	push	hl
+	ld	hl,bnk_table	;
+	add	a,l		;
+	ld	l,a		;
+	jr	nc,$+3		;
+	inc	h		;
+	ld	a,(hl)		;
+	pop	hl
+	ret
+
+    endif
+
 ;--------------------------------------------------------------
 
 ;in  hl: Log. Address
@@ -62,13 +107,16 @@ bnk2phy:
 	cp	CA*16
 	ld	a,c
 	pop	bc
-
 	jr	c,b2p_banked
-	xor	a		; address is in common
-	jr	b2b_cont	;    base is 0
+				; address is in common
+    if 0 ; Memory Map 1
+	ld	a,0		; base is 0
+    else ; Memory Map 2
+	ld	a,1		; same as bank1
+    endif
+
 b2p_banked:
 	call	bnk2log		; get address base
-b2b_cont:
 
 	; fall thru
 
@@ -102,10 +150,10 @@ l2p_i:
 
 ;--------------------------------------------------------------
 ;
-; de: Log. Address
+; hl: Log. Address
 ;
 ;
-; OP: ahl = (bankbase<<12) + (d<<8) + e
+; OP: ahl = (bankbase<<12) + (h<<8) + l
 ;
 ;out ahl: Phys. (linear) Address
 
@@ -137,6 +185,30 @@ hl2p_x:
 	ret			;
 
 
+;--------------------------------------------------------------
+; return logical bank 0 address for given physical address.
+;
+; in: ahl: pyhsical addres (20 bit)
+; out  hl: logical address.
+;	   logical address is in bank 0 or common, no bank number returned
+;
+
+phy2log:
+	or	a
+	ret	z
+
+	push	bc
+	push	hl
+	ld	l,h
+	ld	h,0
+	ld	bc,-16*SYS$CBR
+	add	hl,bc
+	ld	h,l
+	pop	bc
+	ld	l,c
+	pop	bc
+	ret
+
 ;--------------------------------------------------------------
 ; Trampoline for routines in banked ram.
 ; Switch stack pointer to "system" stack in top ram