Apple-2-SW/IIcSystemClock
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This commit is contained in:
Joshua Bell 2020-10-05 20:14:45 -07:00
parent 84e1b1e813
commit 5c74e7326c
1 changed files with 50 additions and 33 deletions
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83
clock.system.s
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@ -6,6 +6,10 @@
.org $2000 .org $2000
.setcpu "65C02" .setcpu "65C02"
;;; TODO: Identify 4 different clock drivers.
;;; * IIc System Clock
.enum MessageCode .enum MessageCode
kInstall = 0 kInstall = 0
kNoSysFile = 1 kNoSysFile = 1
@ -519,51 +523,59 @@ patch_target:
.proc Patch0 .proc Patch0
acia_command_patch1 := * + 1 acia_command_patch1 := * + 1
;; ------------------------------
;; Save COMMAND register
lda PORT2_ACIA_COMMAND lda PORT2_ACIA_COMMAND
pha ; Save command register pha
;; Poke COMMAND register ;; ------------------------------
ldy #3 ; tries ;; Unlock COMMAND register
ldx #22 ; delay ldy #3 ; cycles
ldx #22 ; initial delay
lda #%00001000 lda #%00001000
command_loop: command_loop:
acia_command_patch2 := * + 1 acia_command_patch2 := * + 1
sta PORT2_ACIA_COMMAND sta PORT2_ACIA_COMMAND
: dex : dex ; wait
bne :- bne :-
eor #%00001010 eor #%00001010
ldx #$09 ldx #9 ; repeat delay
dey dey
bne command_loop bne command_loop
;; ------------------------------
;; Read bit out of STATUS register
;; 1 bit at a time in blocks of 4, giving
;; "MMDDhhmm" in high nibble of each byte
ldy #4
ldy #$04 bne read ; always
bne L2289 read_loop:
L2284:
delay_patch1 := * + 1 delay_patch1 := * + 1
lda #kDefaultDelay lda #kDefaultDelay
: dec ; 65C02 : dec ; 65C02
bne :- bne :-
L2289: read:
acia_status_patch1 := * + 1 acia_status_patch1 := * + 1
lda PORT2_ACIA_STATUS lda PORT2_ACIA_STATUS
rol a ; shift out bit 5
rol a rol a
rol a rol a
rol a ror digits_buffer,x ; and into digits
ror $0200,x lsr digits_buffer+1,x
lsr $0201,x
dey dey
bne L2284 bne read_loop
ldy #$04 ldy #4 ; 4 bits per digit
dex dex
bpl L2284 bpl read_loop
pla ; Restore command register ;; ------------------------------
;; Restore COMMAND register
pla
acia_command_patch3 := * + 1 acia_command_patch3 := * + 1
sta PORT2_ACIA_COMMAND sta PORT2_ACIA_COMMAND
@ -577,7 +589,10 @@ acia_command_patch3 := * + 1
;; ...Patch applied to here. ;; ...Patch applied to here.
;; -------------------------------------------------- ;; --------------------------------------------------
;; digits_buffer $200...$207 now has "MMDDhhmm", each digit as a byte ;; digits_buffer $200...$207 now has "MMDDhhmm",
;; each digit in the low (???) nibble of a separate byte (???)
;; e.g. 1/1 01:01 would be ... ???
;; e.g. 12/31 23:59 would be ... ???
;; -------------------------------------------------- ;; --------------------------------------------------
;; Process fields (two digits/bytes at a time) ;; Process fields (two digits/bytes at a time)
@ -607,9 +622,10 @@ digit_loop:
;; -------------------------------------------------- ;; --------------------------------------------------
;; Assign month in DATELO/DATEHI ;; Assign month in DATELO/DATEHI
;; TODO: How do both digits of MM get processed ??? ;; TODO: Why does this process digits_buffer and not
;; digits_buffer + 1?
L22BA: lda digits_buffer ; top nibble is month??? L22BA: lda digits_buffer ; top nibble is month ???
asl a ; DATELO = mmmddddd asl a ; DATELO = mmmddddd
and #%11100000 and #%11100000
ora DATELO ora DATELO
@ -621,6 +637,7 @@ L22BA: lda digits_buffer ; top nibble is month???
sta DATELO+1 sta DATELO+1
;; -------------------------------------------------- ;; --------------------------------------------------
;; ???
ldy #$01 ldy #$01
: lda $0208,y : lda $0208,y
ora #$B0 ora #$B0
@ -661,8 +678,8 @@ time_offset_table := * - 3
Patches: Patches:
;; -------------------------------------------------- ;;; ============================================================
;; Patch #1 ;;; Patch 1:
.proc Patch1 .proc Patch1
firmware_byte := * + 1 firmware_byte := * + 1
@ -687,8 +704,8 @@ L2303: sbc #$01
bne L2303 bne L2303
L2307: lda MOUSE_BTN L2307: lda MOUSE_BTN
rol a rol a
ror $0200,x ror digits_buffer,x
lsr $0201,x lsr digits_buffer+1,x
nop nop
dey dey
bne L2300 bne L2300
@ -699,8 +716,8 @@ L2307: lda MOUSE_BTN
.assert .sizeof(Patch1) = kPatchLength, error, "Patch length" .assert .sizeof(Patch1) = kPatchLength, error, "Patch length"
Patch1_firmware_byte := Patch1::firmware_byte Patch1_firmware_byte := Patch1::firmware_byte
;; -------------------------------------------------- ;;; ============================================================
;; Patch #2 ;;; Patch 2:
.proc Patch2 .proc Patch2
;; Prime the command ;; Prime the command
@ -733,8 +750,8 @@ read_status:
rol a rol a
rol a rol a
rol a rol a
ror $0200,x ror digits_buffer,x
lsr $0201,x lsr digits_buffer+1,x
dey dey
bne read_loop bne read_loop
ldy #$04 ldy #$04
@ -747,8 +764,8 @@ read_status:
.assert .sizeof(Patch2) = kPatchLength, error, "Patch length" .assert .sizeof(Patch2) = kPatchLength, error, "Patch length"
Patch2_delay := Patch2::delay Patch2_delay := Patch2::delay
;; -------------------------------------------------- ;;; ============================================================
;; Patch #3 ;;; Patch 3:
.proc Patch3 .proc Patch3
lda ENVBL lda ENVBL
@ -766,8 +783,8 @@ L2364: dex
L2369: ldy #$04 L2369: ldy #$04
L236B: lda MOUSE_BTN L236B: lda MOUSE_BTN
rol a rol a
ror $0200,x ror digits_buffer,x
lsr $0201,x lsr digits_buffer+1,x
sta X0EDGE2 sta X0EDGE2
nop nop
nop nop