City #37 17 декабря 1999

Программирование

Likbez - a full disassembler ROM (part 28).

    ************* **************** LIKBEZ


(C) P. Yu Fedin



    FULL DESCRIPTION + FULL ROM Disassembler


              TR-DOS 5.04T (5.03)


              For professionals


               And as for those


             WHO WANTS TO BE.



                   continued

Address 6308. Reading a file descriptor, if it was
found. Set 23773, 23781 and the flag of Z: if Z = 1
reads the descriptor, otherwise the error NO FILE.
6308 JP NZ, 985, and if before calling the file was not found
                den, the error

      CALL 5725; download the file descriptor

      RET; Returns

Address 6315. Processing parameters for subroutine
download the file. At the entrance, set 23766, 23769 and
23771; count descriptor file you're looking. At the exit of 
23,771 will be the length of the file to download, 23766 - 0 if 
the length of me, otherwise 3. In HL will load address of the 
file DE - his address on the disk, B - number of sectors to 
load. When loading array or a program in BASIC will be made

Preparation of memory to boot.
6315 LD A, (23766) take the boot flag

      OR A; the beginning and the length taken from the catalogs
                    ha?

      LD HL, (23782), we take the beginning of the file 
descriptor 

      JR Z, 6327, if the parameters do not take from the 
category                     Taloga, then


      LD HL, (23769), we take the starting address, appointed
                    chenny us
6327 LD DE, (23787) take the address of the file on disk

      CP 3, all parameters are assigned user
                    ers?

      LD A, (23786) take the file size in sectors

      PUSH DE; saving the file to address discrete
                    Ke

      LD DE, (23784) take the file length of the descriptor

      JR NZ, 6347, if you want to take it is not there,

                    then we take

      LD DE, (23771), length of load assigned to
                    mi
6347 LD B, A; preserve the file size in seconds
                    tori

      LD (23771), DE; setting the file length to zag
                    manual ultrasonic

      LD A, (23781) file extension C?

      CP "C"

      LD A, B; restore the file length in

                    sectors

      JR NZ, 6397, if the extension is not C, then the length

                    no change

      LD A, B; if the file length in bytes of the corresponding
                    corresponds to its

      CP D; size in sectors, then the length

                    BitTorrent does not change

      JR Z, 6390

      DEC A

      CP D

      LD A, B

      JR Z, 6390

      LD A, (23766), the length assigned to the user?

      CP 3

      LD A, B; restore the file size

                    sectors

      JR Z, 6390, and if we are assigned a length

                    load, it does not change

      XOR A; shipping only completely filled
                    nennye sector

      LD (23766), A

      LD D, B; calculation of the length of the file in bytes

                    of its length

      LD E, 0; sectors

      LD (23771), DE; installation of a new length

      JR 6393
6390 CALL 6427; download the entire file
6393 LD A, B; restore the file size

                    sectors

      CALL 7852; calculation of the number of sectors

                    Download

      LD B, A; preserving its

      LD A, (23781) file extension C?

      CP "C"

      POP DE; recovery addresses on file

                    CD

      RET Z; if the file extension C, the WHO
                    Gates
Error! If the read or write sector
file, there should be a refund. Because of this
errors can not read or write sector file
expansion of B or D.

      PUSH DE; saving the file to address discrete
                    Ke

      CP "B"; extension of B?

      PUSH AF; preserve the file extension

      CALL Z, 6657, if the extension B, the preparation
                    correction to the boot program

                   , In Basic

      POP AF; recovery extension

      CP "D"; extension of D?

      CALL Z, 6732, and if so, preparing for loaded
                    ZEC array

      CALL 6427; length boot has not changed

      LD A, (23772), take the number of sectors for

                    Downloads

      LD B, A

      POP DE; recovery addresses on file

                    CD

      RET; Returns


             to be continued ...