City #05 21 марта 1999

Программирование

Likbez - full description + full disassembler ROM (part 1).

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                     LIKBEZ
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(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.



                     Introduction.


  In our country, from all existing disk interface has spread 
BETADISC interface with the disk operating system, TR-DOS firm 
Technology Research Ltd. This system has many advantages over 
the system using as external memory tape. Operating

system is in the shadow ROM and uses 112
bytes of RAM to accommodate the system
variables, and during operation with the directory drive yet, 
and a buffer size of 257 baytov.Pri This system is compatible 
with the mythical device known as the Interface 1. This version

TR-DOS was made in 1991 by CRAFT.


                 Disks and disk drives.


  Interface supports single-disk drives and
Dual-density, single and double sided. But different versions 
of the TR-DOS impose restrictions on the parameters of the 
drives. With the TR-DOS 5.04T work only drives to move the head 
6 times ms. Note also that different types of drives are not 
always compatible between soboy.Stepen compatibility shown in 
the table below: 


                    Drives
Disc format

             SD, SS SD, DS DD, SS DD, DS


   SD, SS C? N N

   SD, DS C C N N

   DD, SS R? C?

   DD, DS R R C C

Here:
SD - 40-track
DD - 80-track
SS - single-sided
DS - double-sided
C - fully compatible
R - compatible only when reading
N - is not compatible at all
? - Inconsistent, but some drives may

    be compatible


                    Startup.


  If TRDOS starts at address 0 (after pressing
RESET in the 48K computer or software), then
initializing the computer system selects the drive
A and tries to download it and run beysikprogrammu "boot". If 
there is no disk in the drive or disc does not have this 
program, then displays tip and TR-DOS passes to the input mode 
commands. 

  Warning: Do not leave the disc in the drive when you turn on 
or turn off the power, as it can be spoiled!



              AutoCheck drives.


  When the first call to drive TR-DOS will automatically check 
its parameters and stores the relevant system variables. 
Determined by the velocity of the drive heads and the number of 
tracks. 

  Warning: In the routine has an error (a complete list of 
error ROM TR-DOS, see the end of the description). 


      A short list of commands TR-DOS 5.04T.


Team Functions


   * Set the default drive

   40 Informs the TR-DOS, the drive 40-dor.

   80 Informs the TR-DOS, the drive 80-dor.

  CAT output directory disk
 CLOSE # Closing Data File
 COPY Copy files with two drives
 COPY S Copying a file on one drive
 COPY B Copy the entire disk with a floppy drive
 ERASE Erase files
 GO TO Run the file, obtained by

         Button MAGIC
 LIST output expanded catalog drive
 LOAD File Download
 MERGE Merge program in BASIC
 MOVE packing space

  NEW: Rename a File
 OPEN # Open data file
 PEEK Reading sector file
 POKE recording sector file
 RETURN Return from TR-DOS

  RUN Running Programs
 SAVE Record File
 VERIFY A comparison of the files on disk and in memory



                 The command syntax.


  TR-DOS - flexible and you can access it from BASIC and 
machine code. When the shell is waiting for TR-DOS commands 
from you, you see a hint in the form of the name of the drive 
and direction. If the command fails, then the following

prompt will display the old team, you
can edit and re-enter. Most
commands after the return of control TR-DOS, but
There are exceptions, which are described in the descriptions
commands.

  All command parameters are written the same way as in
BASIC. That is, string constants must be
quoted parameters can be variables, functions, expressions, and 
so on. 


             Returning from a TR-DOS in BASIC.


  To return from the TR-DOS command is RETURN. Input format 
commands: RETURN



             Go to the TR-DOS from BASIC.

 To enter the command processor TR-DOS you need to call a 
subroutine in machine code at address 15616. 

  For example:
RANDOMIZE USR 15616


         Executing commands TR-DOS from BASIC.


  In order to run TR-DOS, while in BASIC, before the command 
must be written with a prefix: RANDOMIZE USR 15619: REM:


  In this case, after the team returns to work in BASIC, 
although there are exceptions on occasion. 

  In this command TR-DOS should be the last in
line program in BASIC, but after it can follow the comment. 
Rules for writing comments in the TR-DOS commands, you will 
find descriptions of commands. 

  USR 15619 function returns an error code TR-DOS
(Contents of variable 23 823). A full list of codes
errors can be found at the end of the description.


             Selecting the drive by default.


  Drive by default - is the drive to which
will address the team, without a specified
drive. After initialization, the default drive A.

  TR-DOS supports 4 drives (A, B, C, D). The format of commands 
to change the default drive following:

* 

  The name of the drive - a string of which is taken
first character (A, B, C or D).


              Temporary drive select.


  Permanently alter the drive by default - it is
long and inconvenient. Therefore, in most commands, you can 
specify the drive to which team will have access. To this end, 
before the file name should be written the name of the drive 
with a colon, for example: LOAD "B: PROGRAM"


  If the command does not require a file name, the name
drive with a colon appears after it:
CAT "B:"


            To be continued ...