6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2024-12-25 17:29:50 +00:00
Code Issues Projects Releases Wiki Activity

The RAM driver operates of course in bank #1 (not #2)

Browse Source 
git-svn-id: svn://svn.cc65.org/cc65/trunk@2843 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
cuz 2003-12-27 15:46:23 +00:00
parent f3b1ddfe8a
commit 1af46f9998
1 changed files with 18 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
libsrc/cbm510/cbm510-ram.s
View File

@ -2,12 +2,12 @@
; Extended memory driver for the CBM510 additional RAM banks. Driver works
; without problems when linked statically.
;
; Ullrich von Bassewitz, 2002-12-09 !!! UNTESTED !!!
; Ullrich von Bassewitz, 2002-12-09, 2003-12-27
;
.include "zeropage.inc"
.include "em-kernel.inc"
.include "em-kernel.inc"
.include "em-error.inc"
.include "cbm510.inc"
@ -38,7 +38,7 @@
; ------------------------------------------------------------------------
; Constants
RAMBANK = 2
RAMBANK = 1
OFFS = 2
; ------------------------------------------------------------------------
@ -63,15 +63,20 @@ pagecount: .res 1 ; Number of available pages
INSTALL:
lda #$FF
sta curpage ; Invalidate the current page
sta pagecount ; Assume all memory available
ldx UsrMemTop+2
cpx #RAMBANK ; Top of memory in bank 2?
sec
jsr $FF99 ; MEMTOP
cmp #RAMBANK ; Top of memory in bank 2?
bne @L1 ; No: We can use all the memory
clc
adc UsrMemTop+1
@L1: sta pagecount
txa
sub #OFFS
tya
sbc #$00
sta pagecount
lda #<EM_ERR_OK
@L1: lda #<EM_ERR_OK
ldx #>EM_ERR_OK
; rts ; Run into UNINSTALL instead
@ -112,12 +117,11 @@ MAP: sta curpage ; Remember the new page
sta IndReg
ldy #$00
@L1: lda (ptr1),y
sta window,y
iny
@L1: .repeat 2
lda (ptr1),y
sta window,y
iny
.endrepeat
bne @L1
stx IndReg
@ -154,12 +158,11 @@ COMMIT: lda curpage ; Get the current page
sta IndReg
ldy #$00
@L1: lda window,y
sta (ptr1),y
iny
@L1: .repeat 2
lda window,y
sta (ptr1),y
iny
.endrepeat
bne @L1
stx IndReg