City #33 17 октября 1999

Программирование

Likbez - a full disassembler ROM (part 26).

   *************** **************** 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 5715. Check the status of the file. File Number
set in register A. Gets the Z, if the file is erased
and NZ, if not, as in A will be the first name character
file.
5715 CALL 5725; reading the file descriptor

      LD A, (23773) take the first character filename

      CP 1, inspection of the file

      RET; Returns

Address 5724. Reading a file descriptor. At the entrance to the 
register A place the file number. Descriptor will be loaded at 
23,781. It is also used to address: 5725 - the same as 5724, 
but the file number on the register C.

5726 - the same as 6121, but retains the file number.
5724 LD C, A; transfer a file number in the reg. C
5725 XOR A; transfer the descriptor from the buffer in PA
                rumple
5726 PUSH BC; saving the file number

      CALL 6121; reading sector with a handle and transfer
                bow handle

      POP BC; restore the file number

      RET; Returns

Address 5732. record information about the file. Login: 
descriptor is located 23773 and a battery put the file number.

5732 LD C, A; shift in the C file number

      CALL 5739; reading sector and the replacement of the 
descriptor 

                File it

      JP 7747; rewriting sector

Address 5739. Reading in the buffer descriptor sector
file and change the descriptor. Put a handle on
at 23,773.
5739 LD A, 255, move the handle of the variables in

               buffer

      JR 5726, the same as 6121, but with preservation

               BC

Address 5743. Reservation of seats in the memory. Sets 23759 
and 23843. 5743 LD A, 255; WORKSP used


      LD (23822), A

      CALL 5760; size calculation available

                    Memory

      LD HL, (23649), setting the address of the working domains
                    T

      LD (23759), HL

      JP 7715; allocation of memory space and air
                    Gates

Address 5760. Calculation of the amount of free memory
sectors.

  The size of free memory in bytes will be in BC, and in
sectors - to 23,843.
5760 RST 32, take the amount of free memory
                   Tee in bytes

      DEFW # 1F1A

      LD HL, 65535

      SBC HL, BC

      LD A, H; free less than 16 sectors?

      CP 1916

      JR NC, 5775, and if so,

      LD A, 17, will allocate 16 sectors
5775 DEC A; 1 sector, just in case

      LD (23843), A; sets the size of the free parameters
                   myati sectors

      LD B, A; sets the size of the free parameters
                   myati bytes

      LD C, 0

      RET; Returns

Address 5783. Puts in HL 23767 and 23771 and adds 23,786 (1 
byte) to 23,769 (2 bytes). 5783 LD (23767), HL; installation 
23767 and 23769 

      LD (23771), HL

      LD DE, (23786), the addition of 23,786 and 23,769

      LD HL, (23769)

      LD D, 0

      ADD HL, DE

      LD (23769), HL

      RET; Returns


               to be continued ...