Hi

I'm having problem with the following code compiled under DOSX. I've been stuck on this for a couple of days but seem to get nowhere.

Any help would be much appreciated.

I'm using the orginal Symantec compiler control version 7.2b2. Library: sdx.lib 25/06/1998 10:53

I want to get the computer name of the workstation running my DOSX program so I decided to use an interrupt call 0x5e00, however the machine name is never returned.

Code:


#include <dos.h>
#include <io.h>
#include <stdlib.h>
#include <stdio.h>

void main()
{

char  buffer[17] = "<buffer-------->";

union  REGS  regs_in, regs_out;

regs_in.e.eax = 0x5e00;
regs_in.e.ebx = 0;
regs_in.e.ecx = 0;
regs_in.e.edx = (unsigned)buffer;
regs_in.e.cflag = 0;

regs_out.e.eax = 0;
regs_out.e.ebx = 0;
regs_out.e.ecx = 0;
regs_out.e.edx = 0;
regs_out.e.cflag = 0;

printf("\n REGS IN ax:%x bx:%x cx:%x dx:%x cflag:%x",
regs_in.e.eax,
regs_in.e.ebx,
regs_in.e.ecx,
regs_in.e.edx,
regs_in.e.cflag
);
printf("\n REGS OUT ax:%x bx:%x cx:%x dx:%x cflag:%x",
regs_out.e.eax,
regs_out.e.ebx,
regs_out.e.ecx,
regs_out.e.edx,
regs_out.e.cflag
);


printf("\nbuffer = {%s}", buffer);

int86(0x21, &regs_in, &regs_out);

printf("\nbuffer = {%s}", buffer);

printf("\n REGS IN ax:%x bx:%x cx:%x dx:%x cflag:%x",
regs_in.e.eax,
regs_in.e.ebx,
regs_in.e.ecx,
regs_in.e.edx,
regs_in.e.cflag
);

printf("\n REGS OUT ax:%x bx:%x cx:%x dx:%x cflag:%x",
regs_out.e.eax,
regs_out.e.ebx,
regs_out.e.ecx,
regs_out.e.edx,
regs_out.e.cflag
);

}

Thanks for any help

Regards
Peter

Hello Peter,

peter wrote...
> I'm having problem with the following code compiled under DOSX. I've been stuck on this for a couple of days but seem to get nowhere.
> 
> Any help would be much appreciated.
> 
> I'm using the orginal Symantec compiler control version 7.2b2. Library: sdx.lib 25/06/1998 10:53
> 
> I want to get the computer name of the workstation running my DOSX program so I decided to use an interrupt call 0x5e00, however the machine name is never returned.
> 
> [Code snipped]

The DOSX extender doesn't support several DOS calls directly. These can be called indirectly only. For additional information (such as this machine name) a buffer is needed that can be accessed in both real and protected mode. It's a bit tricky to do. I've rewritten the code to work here. It works when compiled with the actual DigitalMars Compiler and DOSX from http://www.dosextender.com I don't know if it also runs with the DOS extender that was supplied with Symantec 7.2. If not you may try to upgrade.

BTW, when loading the actual DOS-extender you will also find a manual with viewer where all the supported functions are documented.

Regards,
	Heinz

=================== CODE ==================
#include <dos.h>
#include <stdio.h>

#pragma pack(push,2)
struct RMI {   // struct to call real mode interrupts
   unsigned short irq_num;
   unsigned short ds;
   unsigned short es;
   unsigned short fs;
   unsigned short gs;
   unsigned long  eax;
   unsigned long  edx;
};
#pragma pack(pop)

struct XR_BUFFER {
   char __far *pp;     // x32 protected mode pointer;
   unsigned short segm;  // real mode segment
   unsigned short offs;  // real mode offset
};


struct XR_BUFFER GetBufferAdr()
{
   struct XR_BUFFER xr;

   asm {
      push  es
      mov   eax,0x250d     // Get Transfer Buffer Address
      int   0x21
      mov   xr.offs,bx
      shr   ebx,16
      mov   xr.segm,bx
      mov   bx,es          // seg
      mov   DWord Ptr xr.pp,edx
      mov   Word Ptr xr.pp+4,bx
      pop   es
   }
   return xr;
}


int main()
{
   struct XR_BUFFER x32_dos_buffer;
   struct RMI       rmi;
   char             local_buffer[64];
   int              i;

   x32_dos_buffer = GetBufferAdr();
   fprintf(stderr, "Real(%04x:%04x), Prot(%04x:%08x)\n",
        x32_dos_buffer.segm, x32_dos_buffer.offs,
        FP_SEG(x32_dos_buffer.pp), FP_OFF(x32_dos_buffer));

   rmi.irq_num = 0x21;     // DOS interrupt
   rmi.eax     = 0x5e00;   // get machine name
   rmi.edx     = x32_dos_buffer.offs;      /* real mode offset of
transfer buffer */
   rmi.ds      = x32_dos_buffer.segm;      // real mode offset

   asm {
      mov   eax,0x2511
      lea   edx,rmi
      int   0x21
   }

   // now information is in transfer buffer
   // because the extender uses this buffer when doing I/O we copy
   // the contents to a local buffer first;
   for(i=0; i<64 && (local_buffer[i]=x32_dos_buffer.pp[i])!=0; ++i) ;
   printf("Name returned is %s\n", local_buffer);
   return 0;
}//main

================== end CODE ===============

Hi Heinz,

Thanks for your post.

I tried your code on Symantec 7.2 compiler with its dos extender but did not work.

I will do as you have suggested and will look at upgrading the dos extender first to see if it will work with the Symantec compiler, if it still fails I will use DM.

Kind regards

Peter

In article <MPG.1c6c40156eb8758d9896ee@news.digitalmars.com>, Heinz Saathoff says...
>
>Hello Peter,
>
>peter wrote...
>> I'm having problem with the following code compiled under DOSX. I've been stuck on this for a couple of days but seem to get nowhere.
>> 
>> Any help would be much appreciated.
>> 
>> I'm using the orginal Symantec compiler control version 7.2b2. Library: sdx.lib 25/06/1998 10:53
>> 
>> I want to get the computer name of the workstation running my DOSX program so I decided to use an interrupt call 0x5e00, however the machine name is never returned.
>> 
>> [Code snipped]
>
>The DOSX extender doesn't support several DOS calls directly. These can be called indirectly only. For additional information (such as this machine name) a buffer is needed that can be accessed in both real and protected mode. It's a bit tricky to do. I've rewritten the code to work here. It works when compiled with the actual DigitalMars Compiler and DOSX from http://www.dosextender.com I don't know if it also runs with the DOS extender that was supplied with Symantec 7.2. If not you may try to upgrade.
>
>BTW, when loading the actual DOS-extender you will also find a manual with viewer where all the supported functions are documented.
>
>Regards,
>	Heinz
>
>=================== CODE ==================
>#include <dos.h>
>#include <stdio.h>
>
>#pragma pack(push,2)
>struct RMI {   // struct to call real mode interrupts
>   unsigned short irq_num;
>   unsigned short ds;
>   unsigned short es;
>   unsigned short fs;
>   unsigned short gs;
>   unsigned long  eax;
>   unsigned long  edx;
>};
>#pragma pack(pop)
>
>struct XR_BUFFER {
>   char __far *pp;     // x32 protected mode pointer;
>   unsigned short segm;  // real mode segment
>   unsigned short offs;  // real mode offset
>};
>
>
>struct XR_BUFFER GetBufferAdr()
>{
>   struct XR_BUFFER xr;
>
>   asm {
>      push  es
>      mov   eax,0x250d     // Get Transfer Buffer Address
>      int   0x21
>      mov   xr.offs,bx
>      shr   ebx,16
>      mov   xr.segm,bx
>      mov   bx,es          // seg
>      mov   DWord Ptr xr.pp,edx
>      mov   Word Ptr xr.pp+4,bx
>      pop   es
>   }
>   return xr;
>}
>
>
>int main()
>{
>   struct XR_BUFFER x32_dos_buffer;
>   struct RMI       rmi;
>   char             local_buffer[64];
>   int              i;
>
>   x32_dos_buffer = GetBufferAdr();
>   fprintf(stderr, "Real(%04x:%04x), Prot(%04x:%08x)\n",
>        x32_dos_buffer.segm, x32_dos_buffer.offs,
>        FP_SEG(x32_dos_buffer.pp), FP_OFF(x32_dos_buffer));
>
>   rmi.irq_num = 0x21;     // DOS interrupt
>   rmi.eax     = 0x5e00;   // get machine name
>   rmi.edx     = x32_dos_buffer.offs;      /* real mode offset of
>transfer buffer */
>   rmi.ds      = x32_dos_buffer.segm;      // real mode offset
>
>   asm {
>      mov   eax,0x2511
>      lea   edx,rmi
>      int   0x21
>   }
>
>   // now information is in transfer buffer
>   // because the extender uses this buffer when doing I/O we copy
>   // the contents to a local buffer first;
>   for(i=0; i<64 && (local_buffer[i]=x32_dos_buffer.pp[i])!=0; ++i) ;
>   printf("Name returned is %s\n", local_buffer);
>   return 0;
>}//main
>
>================== end CODE ===============

Hi Heinz,

Thanks for the snippet of code. Orignally I couldn't get this code to work on the symantec compiler 7.2 with its built in dos extender.

The code GPF on line

>>   for(i=0; i<64 && (local_buffer[i]=x32_dos_buffer.pp[i])!=0; ++i) ;

For some reason it didn't like the pointer x32_dos_buffer.pp

Therefore I created a pointer from the real mode segment/offset, and this worked, but I don't understand why it didn't like the protected mode ptr.

This worked.
char *ptr = (char *)
(-_x386_get_abs_address(MK_FP(getDS(), 0)) +
(x32_dos_buffer.segm << 4) + x32_dos_buffer.offs);

for(i=0; i<64 && (local_buffer[i]=*ptr)!=0; ptr++, ++i) ;

I compiled the program using "sc -mx compname.cpp"

Anyway, thanks for your help Heinz.



In article <cu7nqg$1uhi$1@digitaldaemon.com>, Peter says...
>
>Hi Heinz,
>
>Thanks for your post.
>
>I tried your code on Symantec 7.2 compiler with its dos extender but did not work.
>
>I will do as you have suggested and will look at upgrading the dos extender first to see if it will work with the Symantec compiler, if it still fails I will use DM.
>
>Kind regards
>
>Peter
>
>In article <MPG.1c6c40156eb8758d9896ee@news.digitalmars.com>, Heinz Saathoff says...
>>
>>Hello Peter,
>>
>>peter wrote...
>>> I'm having problem with the following code compiled under DOSX. I've been stuck on this for a couple of days but seem to get nowhere.
>>> 
>>> Any help would be much appreciated.
>>> 
>>> I'm using the orginal Symantec compiler control version 7.2b2. Library: sdx.lib 25/06/1998 10:53
>>> 
>>> I want to get the computer name of the workstation running my DOSX program so I decided to use an interrupt call 0x5e00, however the machine name is never returned.
>>> 
>>> [Code snipped]
>>
>>The DOSX extender doesn't support several DOS calls directly. These can be called indirectly only. For additional information (such as this machine name) a buffer is needed that can be accessed in both real and protected mode. It's a bit tricky to do. I've rewritten the code to work here. It works when compiled with the actual DigitalMars Compiler and DOSX from http://www.dosextender.com I don't know if it also runs with the DOS extender that was supplied with Symantec 7.2. If not you may try to upgrade.
>>
>>BTW, when loading the actual DOS-extender you will also find a manual with viewer where all the supported functions are documented.
>>
>>Regards,
>>	Heinz
>>
>>=================== CODE ==================
>>#include <dos.h>
>>#include <stdio.h>
>>
>>#pragma pack(push,2)
>>struct RMI {   // struct to call real mode interrupts
>>   unsigned short irq_num;
>>   unsigned short ds;
>>   unsigned short es;
>>   unsigned short fs;
>>   unsigned short gs;
>>   unsigned long  eax;
>>   unsigned long  edx;
>>};
>>#pragma pack(pop)
>>
>>struct XR_BUFFER {
>>   char __far *pp;     // x32 protected mode pointer;
>>   unsigned short segm;  // real mode segment
>>   unsigned short offs;  // real mode offset
>>};
>>
>>
>>struct XR_BUFFER GetBufferAdr()
>>{
>>   struct XR_BUFFER xr;
>>
>>   asm {
>>      push  es
>>      mov   eax,0x250d     // Get Transfer Buffer Address
>>      int   0x21
>>      mov   xr.offs,bx
>>      shr   ebx,16
>>      mov   xr.segm,bx
>>      mov   bx,es          // seg
>>      mov   DWord Ptr xr.pp,edx
>>      mov   Word Ptr xr.pp+4,bx
>>      pop   es
>>   }
>>   return xr;
>>}
>>
>>
>>int main()
>>{
>>   struct XR_BUFFER x32_dos_buffer;
>>   struct RMI       rmi;
>>   char             local_buffer[64];
>>   int              i;
>>
>>   x32_dos_buffer = GetBufferAdr();
>>   fprintf(stderr, "Real(%04x:%04x), Prot(%04x:%08x)\n",
>>        x32_dos_buffer.segm, x32_dos_buffer.offs,
>>        FP_SEG(x32_dos_buffer.pp), FP_OFF(x32_dos_buffer));
>>
>>   rmi.irq_num = 0x21;     // DOS interrupt
>>   rmi.eax     = 0x5e00;   // get machine name
>>   rmi.edx     = x32_dos_buffer.offs;      /* real mode offset of
>>transfer buffer */
>>   rmi.ds      = x32_dos_buffer.segm;      // real mode offset
>>
>>   asm {
>>      mov   eax,0x2511
>>      lea   edx,rmi
>>      int   0x21
>>   }
>>
>>   // now information is in transfer buffer
>>   // because the extender uses this buffer when doing I/O we copy
>>   // the contents to a local buffer first;
>>   for(i=0; i<64 && (local_buffer[i]=x32_dos_buffer.pp[i])!=0; ++i) ;
>>   printf("Name returned is %s\n", local_buffer);
>>   return 0;
>>}//main
>>
>>================== end CODE ===============
>
>