Hi all
i'm trying to use fpc in a old DOS environment by using FreeDOS inside Virtual PC (guess i should be using vmware)
the problem is that i have some low-level code which i would like to port to fpc. FreeDOS came with fpc 2.0.2 which i think is suitable for my needs.
1.) i can't even compile the code
----------------------start------------------------------- C:\>cd
code
C:\code>fpc diskexp.pas
An unhandled exception occurred at $0001072C
:
EAccessViolation : Access
violation
$0001072C
$00010752
$00010CC0
$00010D13
$000100A8
$00006E8F
$00006ED0
$000022E3
$0000279E
----------------------------end------------------------
the strange thing is that if i call fpc without parameters the (huge) usage shows up correctly...is fpc for go32v2 a pmode app? which extender do you recommend me to use?
2.) i have some questions regarding pmode programming with fpc since i never used go32v2. with cwsdpmi, one compiles and links, getting an exe and this exe should be put in the same folder of cwsdpmi.exe. what's the general procedure for go32v2?
3.) in other machine i tried and compiled the code but got some strange results (i can post as soon as a i get home and reach that machine). here is the code:
-------------------------------------------code
start--------------------------------------------------------------------------- program DiskExplorer;
uses crt, dos;
const
BUFLEN = 4608;
BUFSECT = 9;
COMMANDX = 1;
COMMANDY = 20;
COMMAND_RT = 79;
COMMAND_BOT = 24;
STATUSX = 1;
STATUSY = 18;
STATUS_RT = 79;
STATUS_BOT = 19;
LEFTSCREEN = 1;
RIGHTSCREEN = 80;
TOPSCREEN = 1;
BOTTOMSCREEN = 17;
ERROR = -1;
type
buf = array[0..BUFLEN] of byte;
var
finished: boolean;
drive: byte;
sector: integer;
buffer: buf;
regs: Registers;function DiskRead(drive: byte; sector, n_sectors: integer; var buffer: buf): integer;
begin
inline($55/
{this assembly code does nothing more than saving correct stuff, executes DOS}
$8B/$EC/
{interrupts for read/write the disk, restores stuff, flushes DOS buffer and exits }
$83/$C5/$08/
$1E/
$8B/$5E/$00/
$8B/$46/$02/
$8E/$D8/
$8B/$4E/$04/
$8B/$56/$06/
$8A/$46/$08/
$55/
$CD/$25/
$73/$08/
$9D/
$5D/
$89/$46/$0A/
$EB/$08/$90/
$9D/
$5D/
$33/$C0/
$89/$46/$0A/
$1F/
$5D);end;
function DiskWrite(drive: byte; sector, n_sectors: integer; var buffer: buf): integer;
begin
inline($55/
$8B/$EC/
$83/$C5/$08/
$1E/
$8B/$5E/$00/
$8B/$46/$02/
$8E/$D8/
$8B/$4E/$04/
$8B/$56/$06/
$8A/$46/$08/
$55/
$CD/$26/
$73/$08/
$9D/
$5D/
$89/$46/$0A/
$EB/$08/$90/
$9D/
$5D/
$33/$C0/
$89/$46/$0A/
$1F/
$5D);
regs.ax := $D00;
intr($21, regs);end;
procedure Beep;
begin
sound(400);
delay(500);
sound(300);
delay(500);
nosound;
end;
procedure DisplayStartScreen;
begin
clrscr;
window(1,1,80,25);
writeln('=================Disk Examiner=================');
writeln;
writeln;
writeln;
writeln;
writeln('-------------------MAIN MENU-------------------');
writeln('F1: Dump and modify sectors');
writeln;
writeln('F10: Exit');
end;
{ main routine }
begin
drive := 0;
sector := 0;
finished := false;
while not finished do
begin
DisplayStartScreen;
regs.ax := 0;
intr($16, regs);
if regs.ax and $ff = 0 then
begin
clrscr;
case (regs.ax) of
$4400: finished := true;
end;
end;
end;
end.
-------------------------------------------code
end---------------------------------------------------------------------------this code compiles fine with tp5.5 (altough the window function does not work)...what is the correct way to make such a thing in fpc?!
how to mix assembly with fpc in the same procedure/function? i tried but it complained about the labels