City #12 14 мая 1999

Программирование

Likbez - full description + full disassembler ROM (part 8).

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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.



                    continued



             Status register 1818VG-93


  After performing in the status register will be located flags 
showing the result of the command: 


                Discharge Register

    Team

                7 6 5 4 3 2 1 0

Auxiliary R P H F C T I Q
Reading addresses R 0 0 N C W D Q
Reading sector R 0 A N C W D Q
Reading track R 0 0 0 0 W D Q
Record-sector R P E N C W D Q
Track record R P E 0 0 W D Q

Flag values:
R - willingness to drive (1 - not ready).
P - write protection.
H - head load.
E - write error.
A - type of address labels.
F - fault finding.
N - the array is not found.
C - check sum error.
T - head to the track 0 (TR00 signal from the drive)
W - loss of data.
I - the index pulse.
D - data request.
Q - busy (is the command).
Port 255.

  System Registry to select a drive and
perform other ancillary activities. His
Structure:
7 6 5 4 3 2 1 0

                Number of drives (0 - 3).

                Resetting the SH-93 for 0.

                Loading head.

                Side of the disc (0 - lower).

                Recording method (0 - FM, 1 - MFM).
 When you enter this port signals are read:
Bit 7 - INTRQ;
Bit 6 - DRQ.

  Unfortunately, the ports of TR-DOS is available only if
When enabled ROM TR-DOS, which is very difficult to access. But 
to write to the ports can use the following routines: 12227 OUT 
(1931), A 

      RET
7738 OUT (1963), A

      RET
8179 OUT (255), A

      RET
12044 OUT (255), A

      RET
10835 OUT (C), A

      RET

  To read from the ports of such routines do not.

                    Error Codes:

  In the TR-DOS error handling is implemented very ill, but 
still possible to distinguish errors if use two variables: 
23610 and 23823. 

Error Value 23610 23823
error

O.K. Normal completion 255 0
No file (s) required file is not found, 255 1

               den
File exists File already exists 255 2
No space disk is 255 3
Directory full No room in directory 255 4

               Disk
Rec OF Accessing unimportant-255 5

               sponding sector file
No disc No disc in the drive June 26
Disc error Disk error. There are 26 July
Trk XX sec XX 3 options: R - again
Retry, Abort, try, I - prodoIgnore? lzhit from blowing sec
               torus, A-refuse

               operation
Read only disc is write-protected and July 26
Trk XX sec XX There are 3 options (smoRetry, Abort, scrub above)
Ignore?
Stream opened opens a stream is Oct. 25

               busy
Not disk file closes the channel is not 255 1911

               belongs to TR-DOS
Array not required variables 255 1914
found not found on Jan. 1
* BREAK * button is pressed BREAK 20 20

                                        December 1912
Out of RAM not enough operational on March 3

               Memory
Disc error Disk is not owned 255 0

               TR-DOS
Read only attempt to write a 40 - 255 *

               CD TRACK 80
               TRACK drive
* ERROR * Other bugs, wasps, Nov. 12

               novnom syntactic X X +1

* - A copy of the variable with the type of drive
X - any number.
In case of withdrawal messages Retry, Abort, Ignore? Codes
error when replying set A.


               to be continued ...