City #26 30 августа 1999

Программирование

Likbez - a full description and diassembler ROM (part 19).

    ************** *************** 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 4261. Message command LIST.
4261 DEFM "Del."
4265 DEFM "File (s)"

      DEFB 0
4275 DEFM "Title:"

      DEFB 160
4282 DEFB 23,17

      DEFM "Disk Drive:"

      DEFB 0
4298 DEFB 23,16, "", 0
4302 DEFM "40 Track S. Side"

      DEFB 0
4322 DEFM "80 Track S. Side"

      DEFB 0
4342 DEFM "40 Track D. Side"

      DEFB 0
4362 DEFM "80 Track D. Side"

      DEFB 0
4382 DEFB 23,16

      DEFM "Free sector"

      DEFB 0
4398 DEFB 13,13

      DEFM "File Name Start Length Line"

      DEFB 0

Address 4433. Allocation of 546 bytes in the workspace.
Sets 23759.
4433 LD HL, (23649) take the address of the workspace

      LD (23759), HL; installation address space

      LD BC, 546; to allocate 546 bytes

      JP 7715; selection and return

Address 4445. Print the number of HL with zeros.
4445 XOR A; in the tens of thousands including 0

      LD DE, 10000
4449 SBC HL, DE; subtracted from the number 10000

      JR C, 4456, if the number turned out lower

                  10000, then the next level

      INC A; the next ten thousand

      JR 4449; repeat
4556 ADD A, "0"; print tens of thousands

      CALL 4520

      ADD HL, DE; restore the balance of

      XOR A; including 0 thousand
4446 LD DE, 1000

      SBC HL, DE; subtracted from the number 1000

      JR C, 4473, if the number turned out lower

                  1000, the next level

      INC A; the next thousand

      JR 4446; repeat
4473 ADD A, "0"; print thousands

      CALL 4520

      ADD HL, DE; restore the balance of

      XOR A; among hundreds 0

      LD DE, 100
4483 SBC HL, DE; subtracted from the number 100

      JR C, 4490, if the number turned out less than 100,

                  then the next level

      INC A; next hundred

      JR 4483; repeat
4490 ADD A, "0"; print hundreds of

      CALL 4520

      ADD HL, DE; restore the balance of

      XOR A; among dozens 0

      LD DE, 10
4500 SBC HL, DE; subtracted from the number 10

      JR C, 4507, if the number turned out less than 10,

                  then the next level

      INC A; the next ten

      JR 4500; repeat
4507 ADD A, "0"; print tens

      CALL 4520

      ADD HL, DE; restore the balance of

      LD A, L; printing units

      ADD A, "0"

      CALL 4520

      RET; Returns

Address 4520. Same as 15746.
4520 PUSH HL; preservation of HL and DE

      PUSH DE

      CALL 15746; print symbol

      POP DE; restoration DE and HL

      POP HL

      RET; Returns

Address 4528. Check it reaches the end buffer
working with the catalog. Set 23801 and 23756, and
HL put the current buffer address. If the end of the buffer is 
reached, then load the next buffer sector of a directory, but 
the HL will be 23845. 4528 PUSH HL; preservation of HL and BC


      PUSH BC

      LD A, (23801) take the number of floppy 23801

      LD HL, 23798; take a number of the current drive

      CP (HL); assigned a different drive?

      CALL NZ, 15,819, and if so, choose a designated

                    drive

      POP BC; recovery HL and BC

      POP HL

      CALL 1292; check reaches the end of Buffet
                    pa

      LD A, (HL); take the first character filename

      OR A; the end of the directory?

      JP Z, 467; if so, the conclusion

      CP 1, the file is erased?

      CALL Z, 1287, and if so, skip the file

      RET NZ; otherwise return

      JR 4528, if the file was missing, then the types
                    torus


              to be continued ...