JK> I did look them up.  Found them in BSESUB.H.  No mention of a screen
 JK> clearing API call.

From what little I have gathered on the subject of VIO calls I think you
need to implement this yourself.  It is pretty simple to do I imagine
once you have the pointer to the buffer.

This function may not work exactly because I haven't tested it but I
believe the solution is something along these lines:

#define INCL_NOPM
#define INCL_VIO
#include "os2.h"

PBYTE  buffer;
USHORT bufferlen;

void
ClrScreen(BYTE fill,BYTE attrib)
{
  VIOMODEINFO vmi;
  USHORT      i;

  vmi.cb=sizeof(vmi);
  VioGetMode(&vmi,0);

  VioGetBuf((PULONG)buffer,bufferlen,0);

  for(i=0;i<(vmi.col*vmi.row*2);i+=2){
    buffer[i]=fill;
    buffer[i+1]=attrib;
  }
}

Cheers,
Robin.

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