;OS-receiving code

 include "settings.inc"
 include "ti83plus.inc"
 include "equates.inc" 
 SEGMENT Main
 GLOBALS ON

 EXTERN PutSApp,IGetKey,keyLoop,StartApp,DispHexA,ReceiveByte,SendByte,DispHexArray,myPage,tempByte
 EXTERN currentPage,currentOffset,DispHexHL,Abackup,DEbackup,HLbackup,BCbackup,myDispHexA
 EXTERN sRemoteLinkError,sendDeviceInfo

ReceiveOS:
       B_CALL ClrLCDFull
       B_CALL HomeUp
       ld hl,sWarning
       call PutSApp
recvKeyLoop:
       B_CALL GetKey
       cp kQuit
       jr z,StartApp
       cp kClear
       jr z,StartApp
       cp kMode
       jr z,StartApp
       cp kEnter
       jr nz,recvKeyLoop
       B_CALL ClrLCDFull
       B_CALL HomeUp
       ld hl,sReceiving
       call PutSApp
       ld hl,sRemoteLinkError
       call APP_PUSH_ERRORH
beginTransfer:
       B_CALL Get4BytesNC
       cp 2Dh
       jr z,sendInfoPacket
       cp 68h
       jr nz,pastReady
       ld h,56h
       call Send4Bytes
       jr beginTransfer
sendInfoPacket:
       call sendDeviceInfo
       jr StartApp
pastReady:
       cp 06h
       jr z,$F
       B_JUMP ErrLinkXmit
$$:    B_CALL GetSmallPacket
       call DispHexArray
       ld hl,1
       ld (curRow),hl
       ld hl,sUnlocking
       call PutSApp
       ld hl,6
       ld (curRow),hl
       ld hl,sWriting
       call PutSApp
       ld hl,sUnlockName
       rst 20h
       B_CALL ChkFindSym
       jr c,errUndefined
       ld a,b
       or a
       jr z,$F
errUndefined:
       B_JUMP ErrUndefined
$$:    ex de,hl
       ld c,(hl)
       inc hl
       ld b,(hl)
       inc hl
       inc hl
       inc hl
       dec bc
       dec bc
       ld de,userMem
       di
;This WILL destroy RAM and the OS, no turning back now
       ldir
       di
;       ld a,07h
;       ld hl,45ADh
;       ld de,0C000h
;       ld bc,1000h
;       B_CALL FlashToRam
;       call userMem
       ld a,1
       ld (appInfo+2),a
       rst 28h
       DW 50CBh
;       ld hl,unlockFlash
;       ld de,appBackUpScreen
;       ld bc,unlockFlashEnd-unlockFlash
;       ldir
;       call appBackUpScreen
;Set up BCALL replacement
       ld hl,doBankedCallIX
       ld de,appBackUpScreen
       ld bc,doBankedCallIXEnd-doBankedCallIX
       ldir
;Erase all relevant Flash sectors
       xor a
       ld ix,_EraseFlashPage
       call appBackUpScreen
       ld a,4
       ld ix,_EraseFlashPage
       call appBackUpScreen
       ld a,70h
       ld ix,_EraseFlashPage
       call appBackUpScreen
       ld a,74h
       ld ix,_EraseFlashPage
       call appBackUpScreen
       ld a,78h
       ld ix,_EraseFlashPage
       call appBackUpScreen
       ld a,7Ch
       ld ix,_EraseFlashPage
       call appBackUpScreen
       ld h,9
       call Send4Bytes ;continue
       call get4Bytes ;acknowledge
;Some sort of header
       call get4Bytes ;machine ID, command, size word
       ld bc,(header+2)
headerLoop:
       push bc
       call ReceiveByte ;data byte
       pop bc
       dec bc
       ld a,b
       or c
       jr nz,headerLoop
       call ReceiveByte ;checksum
       call ReceiveByte
       ld h,56h
       call Send4Bytes ;acknowledge
       di
receiveOSLoop:
;Header packet with page/offset
       call get4Bytes ;machine ID, command, size word
       ld a,(header+1)
       cp 92h
       jr z,receiveOSDone ;EOT
       ld bc,(header+2)
       ld hl,appData
$$:    push bc
       push hl
       call ReceiveByte
       pop hl
       pop bc
       ld (hl),a
       inc hl
       dec bc
       ld a,b
       or c
       jr nz,$B
       call ReceiveByte ;checksum bytes
       call ReceiveByte
       ld h,56h
       call Send4Bytes ;acknowledge
       ld h,9
       call Send4Bytes ;continue
       call get4Bytes ;acknowledge
       ld hl,(appData+6)
       ld (currentOffset),hl
       ld a,(appData+8)
       cp 8
       jr c,$F
       push af
       in a,(2)
       and 80h
       pop bc
       ld a,b
       jr z,$F
       set 5,a
       push af
       in a,(21h)
       and 3
       pop bc
       ld a,b
       jr z,$F
       set 6,a
$$:    ld (currentPage),a
;These don't work because PutC no longer exists
;       ld hl,7
;       ld (curRow),hl
;       ld a,(currentPage)
;       call myDispHexA
;       ld a,(currentOffset+1)
;       call myDispHexA
;       ld a,(currentOffset)
;       call myDispHexA
;Data packet of 256 bytes to go to page/offset
       call get4Bytes ;machine ID, command, size word
       ld bc,(header+2)
       ld hl,appData
$$:    push bc
       push hl
       call ReceiveByte
       pop hl
       pop bc
       ld (hl),a
       inc hl
       dec bc
       ld a,b
       or c
       jr nz,$B
       call ReceiveByte ;checksum bytes
       call ReceiveByte
       ld de,(currentOffset)
       ld a,(currentPage)
       ld hl,appData
       ld bc,256
       ld ix,_WriteFlash
       call appBackUpScreen
       ld h,56h
       call Send4Bytes ;acknowledge
       jr receiveOSLoop
receiveOSDone:
       ld h,56h
       call Send4Bytes ;acknowledge
;       res indicOnly,(iy+indicFlags)
       jp 0000h
;       ld hl,7
;       ld (curRow),hl
;       B_CALL DispDone ;if receiving anything not TI-OS compatible, this is bad
;$$:    B_CALL GetCSC
;       or a
;       jr z,$B
;       jr StartApp
doBankedCallIX:
       ld (Abackup),a
       ld (DEbackup),de
       ld (HLbackup),hl
       ld (BCbackup),bc
       in a,(6)
       push af
       ld a,7Fh
       call translatePage
       out (6),a
       push ix
       pop hl
       res 7,h
       set 6,h
       ld e,(hl)
       inc hl
       ld d,(hl)
       push de
       pop ix
       ld de,returnPoint-doBankedCallIX+appBackUpScreen
       push de
       ld a,(Abackup)
       ld de,(DEbackup)
       ld hl,(HLbackup)
       ld bc,(BCbackup)
       jp (ix)
returnPoint:
       pop af
       out (6),a
       ret
doBankedCallIXEnd:
translatePage:
       push af
       in a,(2)
       and 80h
       pop bc
       ld a,b
       jr z,_83pPage
       push af
       in a,(21h)
       and 3
       pop bc
       ld a,b
       ret nz
       and 3Fh
       ret
_83pPage:
       and 1Fh
       ret
get4Bytes:
       call ReceiveByte
       ld (header),a
       call ReceiveByte
       ld (header+1),a
       call ReceiveByte
       ld (header+2),a
       call ReceiveByte
       ld (header+3),a
       ret
Send4Bytes:
       push hl
       ld a,73h
       call SendByte
       pop af
       call SendByte
       xor a
       call SendByte
       xor a
       jr SendByte
sWarning:
       DB "!!!!WARNING!!!!!"
       DB "                "
       DB "Make sure that  "
       DB "prgmUNLOCK is   "
       DB "correct and then"
       DB "press ",LlBrack,"ENTER] to"
       DB "continue.",0
sUnlocking:
       DB "Unlocking",0CEh,0
sReceiving:
       DB "Receiving",0CEh,0
sWriting:
       DB "DO NOT INTERRUPT",0
sUnlockName:
       DB ProtProgObj,"UNLOCK",0
;myPutC:
;       push af
;       push hl
;       call sub_5950
;       res 0,(iy+8)
;       ld hl,curCol
;       inc (hl)
;       pop hl
;       pop af
;       ret
;sub_5950:
;       di
;       push af
;       push bc
;       push de
;       push hl
;       push ix
;       res 2,(iy+2)
;       bit 1,(iy+0Dh)
;       jr z,$F
;       call sub_600C
;       ld (hl),a
;$$:    ld l,a
;       ld h,0
;       add hl,hl
;       add hl,hl
;       add hl,hl
;       call unk_39CD
;       push hl
;       pop ix
;       ld a,(curRow)
;       call sub_670D
;       ld (8451h),a
;       ld a,(curCol)
;       and 1Fh
;       add a,20h
;       ld b,a
;       xor a
;       call LCD_delay
;       out (10h),a
;       ld a,(8451h)
;       call sub_5941
;       call some_output
;       ld a,b
;       call LCD_delay
;       out (10h),a
;       ld b,8
;loc_59A2:
;       xor a
;       dec b
;       jr z,loc_59AB
;       ld a,(ix+0)
;       inc ix
;loc_59AB:
;       inc b
;       sla a
;       bit 3,(iy+5)
;       jr z,loc_59E9
;       xor 3Eh
;loc_59B6:
;       push af
;       ld a,(curCol)
;       and 1Fh
;       jr z,loc_59E6
;       add a,1Fh
;       call LCD_delay
;       out (10h),a
;       call sub_5928
;       or 1
;       bit 0,(iy+8)
;       jr z,loc_59D2
;       and 3Eh
;loc_59D2:
;       call LCD_delay
;       out (11h),a
;       ld a,(curCol)
;       and 1Fh
;       add a,20h
;       call LCD_delay
;       out (10h),a
;       call sub_5932
;loc_59E6:
;       pop af
;       jr loc_59EF
;loc_59E9:
;       bit 0,(iy+8)
;       jr nz,loc_59B6
;loc_59EF:
;       call LCD_delay
;       out (11h),a
;       djnz loc_59A2
;       ld a,1
;       call LCD_delay
;       out (10h),a
;loc_59FD:
;       pop ix
;loc_59FF:
;       pop hl
;       pop de
;       pop bc
;       pop af
;       ret
;sub_600C:
;       push af
;       push bc
;       push de
;       ld hl,(curRow)
;       ld a,l
;       call Atimes16
;       add a,h
;       ld l,a
;       ld h,0
;       ld de,8508h
;       add hl,de
;       pop de
;       pop bc
;       pop af
;       ret
;sub_670D:
;       add a,a
;       add a,a
;       add a,a
;       add a,80h
;       ret
;sub_5941:
;       call some_output2
;       cp 80h
;       ret c
;       cp 0C0h
;       ret nc
;       call LCD_delay
;       out (10h),a
;       ret
;sub_5928:
;       call LCD_delay
;       in a,(11h)
;       call LCD_delay
;       in a,(11h)
;sub_5932:
;       push af
;       ld a,(8451h)
;       add a,8
;       sub b
;loc_5939:
;       call sub_5941
;       call some_output
;       pop af
;       ret
;Atimes16:
;       add a,a
;       add a,a
;       add a,a
;       add a,a
;       ret
;unk_39CD:
;       ld de,0C000h
;       add hl,de
;       ld de,845Ah
;       push af
;       push bc
;       ld b,8
;$$:    ld a,(hl)
;       ld (de),a
;       inc hl
;       inc de
;       djnz $B
;       pop bc
;       pop af
;       ld hl,845Ah
;       ret

;some_output2:
;       push af
;       ld a,7
;       call LCD_delay
;       out (10h),a
;       pop af
;       ret
;some_output:
;       push af
;       ld a,5
;       call LCD_delay
;       out (10h),a
;       pop af
;       ret
;LCD_delay:
;       push af
;$$:    in a,(2)
;       and 2
;       jr z,$B
;       bit 3,(iy+41h)
;       call nz,small_delay
;       call nz,small_delay
;       call nz,small_delay
;       pop af
;       ret
;small_delay:
;       push af
;       inc hl
;       dec hl
;       pop af
;       ret
;unlockFlash:
;       in a,(6)
;       push af
;       ld a,7Ch
;       out (6),a
;       ld hl,mystupidpoint-unlockFlash+appBackUpScreen
;       push hl
;       push af
;       ld a,1
;       jp 669Dh
;mystupidpoint:
;       pop af
;       out (6),a
;       ret
;unlockFlashEnd: