6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2024-06-07 23:29:39 +00:00
Code Issues Projects Releases Wiki Activity

Systime implementation for the CBM610, derived from the C64.

Browse Source 
git-svn-id: svn://svn.cc65.org/cc65/trunk@4225 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
uz 2009-09-24 20:12:40 +00:00
parent 83be732983
commit 753bbab40d
1 changed files with 79 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

88
libsrc/cbm610/systime.s
View File

@ -1,5 +1,6 @@
;
; Ullrich von Bassewitz, 12.11.2002
; Stefan Haubenthal, 2009-07-27
; Ullrich von Bassewitz, 2009-09-24
;
; time_t _systime (void);
; /* Similar to time(), but:
@ -9,20 +10,89 @@
; */
;
.export __systime
.include "time.inc"
.include "cbm610.inc"
.include "extzp.inc"
.importzp sreg
.import sys_bank, restore_bank
.importzp tmp1, tmp2
;----------------------------------------------------------------------------
.code
.proc __systime
.proc __systime
lda #$FF
tax
sta sreg
sta sreg+1
rts ; Return -1
; Switch to the system bank
jsr sys_bank
; Read the clock
ldy #CIA::TODHR
lda (cia),y
bpl AM
and #%01111111
sed
clc
adc #$12
cld
AM: jsr BCD2dec
sta TM + tm::tm_hour
ldy #CIA::TODMIN
lda (cia),y
jsr BCD2dec
sta TM + tm::tm_min
ldy #CIA::TODSEC
lda (cia),y
jsr BCD2dec
sta TM + tm::tm_sec
ldy #CIA::TOD10
lda (cia),y ; Dummy read to unfreeze
; Restore the bank
jsr restore_bank
; Convert to a time
lda #<TM
ldx #>TM
jmp _mktime
.endproc
;----------------------------------------------------------------------------
; dec = (((BCD>>4)*10) + (BCD&0xf))
.proc BCD2dec
tax
and #%00001111
sta tmp1
txa
and #%11110000 ; *16
lsr ; *8
sta tmp2
lsr
lsr ; *2
adc tmp2 ; = *10
adc tmp1
rts
.endproc
;----------------------------------------------------------------------------
; TM struct with date set to 1970-01-01
.data
TM: .word 0 ; tm_sec
.word 0 ; tm_min
.word 0 ; tm_hour
.word 1 ; tm_mday
.word 0 ; tm_mon
.word 70 ; tm_year
.word 0 ; tm_wday
.word 0 ; tm_yday
.word 0 ; tm_isdst