City #41 06 марта 2000

Программирование

Likbez - a full disassembler ROM (part 31).

   *************** **************** 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 6804. The calculation of sector addresses a file on 
disk by its number in the file. Entry: 23767 install and 23769 
and put into register B file length in sectors and in DE - 
address of the file to disk. Output: DE bottles sector address 
on the disk, and B is located 1. 

6804 LD A, (23769) take the number of sectors in the file

      LD C, B

      LD B, A

      LD A, C

      CP B; it is smaller than the number of

                    sectors in the file?

      JR C, 6838, and if not, then the error
Warning, Error! You will not be able to download the latest
Sector File, as his number is equal to the number of sectors in 
the file. 

      LD A, B; it is 0?

      OR A

      JP Z, 7450, and if so, what syntax

                    error

      DEC B; he was 1?

      JR Z, 6832, and if so, its address is

                    file address

      LD A, 16, 16 sectors per track
6823 INC E; address calculation sector

                    CD

      CP E

      JR NZ, 6830

      LD E, 0

      INC D
6830 DJNZ 6823
6832 LD B, 1; load should be 1 sector

      LD HL, (23767) take the address of the boot sector

      RET; Returns
6838 LD HL, 10733; mail messages REC.O / F

      LD A, 5; error code - 5

      JP 7242; processing errors

Address 6846. Checking for file and free
place in the directory. File name put on a stack calculator. It 
is also used to address 6852 (check availability of your 
drive). 

CALL 10 543 6846; set name and file search

      JP Z, 7248, and if found, then FILE EXISTS
6852 CALL 1021; boot sector of the buffer 8 to
                   Cones 0

      LD A, (24073) 128 files on disk?

      CP 128

      JP Z, 10,019, and if so, what message DIRECTORY FULL

      RET; otherwise return

Address 6864. Runs the command SAVE. Set
23611 and 23825. Used as addresses: 6951 -
write programs in BASIC. Set 23773 and
23781. 6995-record file. Set 23773, 23781,
23767, 23769 and 23771.
6864 CALL 6226; zeroing 23824

      LD HL, 0; autostart BASIC not produ
                    dit

      LD (23761), HL

      CALL 7647; placing the file name on stack

                    Calculator

      CALL 7564; take the current character

      CP 175; this CODE?

      JR Z, 6969, and if so, the reception began and the length
                    Ny

      CP 202; this LINE?

      JR NZ, 6904, and if not, then check the rest

                    Extensions

      CALL 7691; reception line auto-BASIC

      CALL 7541; if checking syntax, then

                    Returns

      LD HL, (23771) auto-setup line

                    BASIC

      LD (23761), HL

      LD HL, 23781

      JR 6943 and the transition to writing BASIC
6904 CP 170, the current character SCREEN $?

      JR NZ, 6925, and if not, then check extension
                    of DATA

      LD HL, 16384; beginning of the file - 16384

      LD (23767), HL

      LD HL, 6912, its length - 6,912 bytes

      LD (23769), HL

      LD (23771), HL

      JR 6984, recording a file with C


              to be continued ...