City #17 06 июля 1999

Программирование

Likbez - a full description and disassembler ROM (part 12).

--------------------------------------------------
                     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 688. Transfer of three bytes of address for HL
at DE.
688 LD B, 3; the number of bytes
690 LD A, (HL); transfer bytes

      LD (DE), A

      INC HL; address the next byte

      INC DE

      DJNZ 690, repeat until the end

      RET; Returns

Address 697. Stop the drive. A drop in value of the system 
registry. 697 LD B, 32 and 32 repeat

699 PUSH BC; retention of the number of repetitions

      XOR 8; switch bit 3

      OUT (255), A; Loading System Registry

      PUSH AF; conservation value of the system

                  Register

      LD A, 5; delay in 17,962 cycles

      CALL 15871

      POP AF; restore the values ​​of system
                  On Register

      POP BC; and number of repetitions

      DJNZ 699; repeat until the end

      RET; Returns

Address 715. Command processor. Also used
to address:
751 - performance of the team. Compressed team place
in the buffer command line;
778 - performance of the team. Set all to 467,
23825 and 23825, download HL.
715 LD HL, (23836), clearing the stack

      DEC HL

      DEC HL

      LD SP, HL

      CALL 8433; change memory

      CALL 7555; opening thread 0

      LD A, (23830), the choice of drive D:

      OR 3

      CALL 697; stop it

      LD A, (23830), stopping the current drive

      CALL 697

      XOR A; error messages are printed

      LD (23829), A

      CALL 8501; the adoption team

      CALL 12338; compression command line
751 CALL 7583, cleaning the bottom of the screen

      LD HL, 715; return to the team about
                    core processor

      LD (23834), HL

      XOR A; error was not

      LD (23823), A

      LD HL, (23641) take the address of the command line

      PUSH HL; save it

      LD DE, 23840; buffer address

      CALL 688, preserving the first three characters

                    line

      POP HL; restoration of the row address

      LD (23825), HL; installation address command

                    line
778 LD A, (HL); take the first character

      LD B, A; save it

      AND 128, the code is less than 128?

      LD A, B; recovery of the symbol

      JR Z, 794, and if the code is less than 128, then di
                    skovod not set

      CP 254; it RETURN?

      JR Z, 794 and, if so, the drive was not tired
                    pour

      PUSH AF; preserve the character

      CALL 15816; revitalization drive factory de
                    by Remark

      POP AF; recovery of the symbol
794 LD HL, 12275; address table commands

      DEC HL

      LD C, 0; check first team
800 INC C

      LD D, A; preserve the character

      LD A, 21, passed the entire table?

      CP C

      JP C, 467; if so, the conclusion
It would be better to put here JP C, 7450 for issuing
message "* ERROR *".

      LD A, D; recovery of the symbol

      INC HL; address the following commands in the table
                    face

      CP (HL); characters match?

      JR NZ, 800; if not, repeat

      CP 254; typed the command RETURN?

      CALL NZ, 10,570, and if not, then the creation of buffer

      LD A, 9; to search for the file to 9 bytes

      LD (23814), A

      XOR A; error was not

      LD (23823), A

      LD (23766), A; the file extension to make

      LD (23824), A; the case of loading or verifi
                    cation file

      LD HL, 23611; check the syntax of the line

      RES 7, (HL)

      LD B, 0; translation team number two
                    byte form

      LD HL, 12296; mail address table podprog
                    Ramm

      DEC C; assume command from scratch

      SLA C; multiplication rates routines

                    2

      ADD HL, BC; definition address table

      LD E, (HL); take the address of the subroutine

      INC HL

      LD D, (HL)

      EX DE, HL; carries it to the HL

      PUSH HL; save it

      LD DE, 857; refund will be in 857

      PUSH DE

      JP (HL); subroutine call
857 LD HL, 23611; command execution

      SET 7, (HL)

      POP HL; recovery addresses podprog
                    FRAMEWORK

      JP (HL); subroutine call


               to be continued ...