Program: DISK13IO.TPU
Description: Sector I/O (Interrupt $13) Unit for Turbo Pascal 5.0
Author: Kurt Diesch
Applied Micro Systems Technology
PO Box 1596, Welch Ave. Station
Ames, Iowa 50010
(515) 292-0426 CIS [71121,1404]
Member - Association of Shareware Professionals
Copyright 1988 AMST, all rights reserved.
PROGRAM USE
DISK13IO.TPU is a Turbo Pascal 5.0 unit designed to allow
programmers to add disk sector I/O (interrupt $13) routines into
their programs. The routines in DISK13IO will only operate on
floppy disks. The entire unit is self-contained, including
advanced error checking and error recovery. Functions available
through DISK13IO include:
ResetDrives ( reset disk drive system after an I/O error )
GetDiskStatus ( get results of last Int $13 operation )
ReadSectors ( read absolute disk sectors)
WriteSectors ( write absolute disk sectors )
VerifySectors ( verify absolute disk sectors (CRC check) )
FormatDisk ( format a floppy disk in drive A or B,
all disk sizes)
To use the DISK13IO.TPU routines, place the DISK13IO declaration
in the interface section of your program or unit. For example, a
unit heading in your program might appear as follows:
unit DISKTEST;
interface
uses Crt,Dos,DISK13IO;
The DISK13IO routines occasionally must perform some screen I/O
to report errors or to indicate the status of the format
operation. DISK13IO will automatically save the current window
setting, screen contents, and cursor location and restore these
settings after the screen I/O is done. When screen output is
necessary, a box will appear in the center of the screen. The
foreground and background colors of the output box are controlled
by a global variable of type byte called "Disk13IOAttr". This
variable initially assumes the value of the Turbo variable
"TextAttr" when your controlling program starts. (See your Turbo
manual for a discussion of TextAttr in the section of the Turbo
Crt unit). You can change the foreground and background colors
of the display window by setting Disk13IOAttr in the same way you
would change TextAttr. The location of the output window cannot
be altered.
+------------------------+
| |
| SAMPLE OUTPUT WINDOW |
| |
| |
+------------------------+
The remainder of this documentation describes each of the
routines in DISK13IO.TPU. Each routine is descibed with input
and output parameters. For a complete discussion of these
routines, consult a DOS Technical Reference manual or a book such
as Norton's Programmer's Guide to the IBM PC & PS/2.
************************** IMPORTANT *************************
IT IS THE RESPONSIBILITY OF THE PROGRAMMER TO ENSURE THAT ALL
PARAMETERS PASSED TO THE DISK13IO.TPU ROUTINES ARE WITHIN
ACCEPTABLE RANGES. ALSO BE SURE YOU DO NOT USE THE WRITESECTORS
FUNCTION UNLESS YOU UNDERSTAND WHAT YOU ARE DOING. THE FORMAT
DISK ROUTINE WILL CHECK TO MAKE SURE THAT YOU SPECIFY DRIVE A OR
B AND WILL NOT ALLOW FORMATTING OF ANY OTHER DRIVES. ALL OF
THESE ROUTINES WILL ONLY OPERATE ON DRIVES A OR B.
****************************************************************
procedure ResetDrives (Drive:byte);
-----------------------------------
Input: Drive : byte Drive to reset (0=A, 1=B, ...)
IBM documentation indicates that this
call will reset the entire disk system.
Other references indicate that only the
specified drive is reset. Output:
none
function GetDiskStatus : byte;
------------------------------
Input: none
Output: Returns the error code generated by the last
Interrupt $13 operation. The DISK13IO routines use this
function internally to check for errors, and if you call
this routine after using a DISK13IO routine, you will
get the same error code as the DISK13IO routine last
processed. If no error occurred, this function will
return 0.
function ReadSectors (see below) : boolean;
-------------------------------------------
Input: Quiet : boolean True to suppress error messages
DType : byte Drive type
(1=360K 5-1/4 2=1.2M 5-1/4 )
(3=720K 3-1/2 4=1.44M 3-1/2)
Drive : byte Drive to read from (0=A, 1=B)
Track : byte Track number to read (0...)
Side : byte Side to read (0 or 1 for floppy disks)
SSect : byte Starting sector to read (1...)
NSect : byte Number of sectors to read
(1... DO NOT USE 0!)
var Buffer Variable to store data
(512 bytes/sector read)
Output: True if operation was successful, otherwise false.
Data read from sectors will be contained in Buffer if
the operation was successful.
function WriteSectors (see below) : boolean;
--------------------------------------------
Input: Quiet : boolean True to suppress error messages
DType : byte Drive type
(1=360K 5-1/4 2=1.2M 5-1/4 )
(3=720K 3-1/2 4=1.44M 3-1/2)
Drive : byte Drive to write to (0=A, 1=B)
Track : byte Track number to write (0...)
Side : byte Side to write
(0 or 1 for floppy disks)
SSect : byte Starting sector to write (1...)
NSect : byte Number of sectors to write
(1... DO NOT USE 0!)
var Buffer Variable with data
(512 bytes/sector to write)
Output: True if operation was successful, otherwise false.
function VerifySectors (see below) : boolean;
---------------------------------------------
Input: Quiet : boolean True to suppress error messages
DType : byte Drive type
(1=360K 5-1/4 2=1.2M 5-1/4 )
(3=720K 3-1/2 4=1.44M 3-1/2)
Drive : byte Drive to verify (0=A, 1=B)
Track : byte Track number to verify (0...)
Side : byte Side to verify
(0 or 1 for floppy disks)
SSect : byte Starting sector to verify (1...)
NSect : byte Number of sectors to verify
(1... DO NOT USE 0!)
Output: True if operation was successful, otherwise false.
function FormatDisk (see below) : boolean;
------------------------------------------
Input: DType : byte Drive type
(1=360K 5-1/4 2=1.2M 5-1/4 )
(3=720K 3-1/2 4=1.44M 3-1/2)
Drive : byte Drive to format (0=A, 1=B)
MaxBad : byte Maximum allowable bad sectors
from verify
VLabel : string[11] Optional volume label
Verify : boolean True forces verify with bad
sector marking
ShowRes: boolean True shows final format results
Output: True if format operation was successful, otherwise
false. As the format process takes place, a text window
will appear as shown below to indicate the progress of
the disk format. If the Verify option is on, FormatDisk
will mark bad sectors on the disk. Unlike DOS FORMAT,
FormatDisk only marks the bad sectors, not a whole track
at a time.
+-------------------------+
| AMST DISK FORMATTER |
| |
| Formatting Track xx |
| |
+-------------------------+
alternating with (if Verify=True)
+-------------------------+
| AMST DISK FORMATTER |
| |
| Verifying Track xx |
| Bad Sectors xxx |
+-------------------------+
then
+-------------------------+
| AMST DISK FORMATTER |
| |
| Writing FAT info... |
| |
+-------------------------+
and finally (if ShowRes=True)
+-------------------------+
| xxxxxxx bytes total |
| xxxxxxx marked as bad |
| xxxxxxx bytes available |
| **** press any key **** |
+-------------------------+
Following is an short program to demonstrate how you to use
DISK13IO.TPU in your programs to format a disk.
(AUTHOR'S NOTE: I don't really program this way!!!).
{========= EXAMPLE DISK FORMAT PROGRAM ================}
Program DiskFormat;
Uses Crt,Dos,DISK13IO;
const
CR = #13;
ESC = #27;
var
DriveNumber,
DriveType : byte;
UserChoice : char;
begin
ClrScr;
Writeln('TEST DISK FORMAT PROGRAM');
Writeln;
Write('Enter drive letter (A or B, [Esc] to Exit): ');
repeat
UserChoice:=UpCase(Readkey);
if UserChoice = ESC then Halt;
until UserChoice in ['A','B'];
Writeln;
Writeln;
DriveNumber := Ord(UserChoice)-65;
Writeln(' 1 = 360K 5-1/4" 3 = 720K 3-1/2"');
Writeln(' 2 = 1.2M 5-1/4" 4 = 1.44M 3-1/2"');
Writeln;
Write('Enter drive type ([Esc] to Exit): ');
repeat
UserChoice:=Readkey;
if UserChoice = ESC then Halt;
until UserChoice in ['1'..'4'];
DriveType:=Ord(UserChoice)-48;
Writeln;
Writeln;
Write('Insert blank disk in drive ',
Chr(DriveNumber+65),
' and press [Return] ([Esc] to abort)');
repeat
UserChoice:=Readkey;
if UserChoice = ESC then Halt;
until UserChoice=CR;
if FormatDisk(DriveType,DriveNumber,0,
'TEST VOLUME',True,True) then ;
end.
{=============================================================}
DISK13IO.TPU will handle all errors as they occur by placing an
error message on the screen and giving the user the option of
retrying the operation, or aborting the current operation. If
the user aborts, control will be returned to your parent program.
For example:
+-------------------------+
| |
| Drive not ready |
| A)bort or R)etry |
| |
+-------------------------+
In addition to "A", the [Esc] key also serves to abort after an
error.
TECHNICAL INFORMATION
DISK13IO.TPU is written entirely in Turbo Pascal 5.0. There is
no inline assembly code, and the entire program was written using
AMST developed routines. I use these routines in many of my
programs, (custom, shareware, and personal). The entire unit is
self-contained and does not rely on any other units (except Crt
and DOS in the Turbo library).
DISK13IO.TPU has been tested on the following equipment:
AMT-286 with one 360K and one 1.44M drive
AMT-286 with one 1.2M drive
Zenith Z-248 with one 360K and one 1.2M drive
Zenith Z-159 with one 360K drive
Zenith Z-183 with one 720K drive
Zenith Z-181 with two 720K drives
If you have any problems with the program, call or write AMST
with a description of the problem.
Kurt Diesch
Friday, October 28, 1988
11:30 a.m.
Ames, Iowa
Copyright 1988, All rights reserved.
| 
Kurt H. Diesch