WInfo - v2.0 by Alan DeKok
          Minor modifications to make WInfo use the I$Attach system call
          to find the device table entry of the window in question.
          The old WInfo rooted through system memory by hand, and used
          a FIXED device table size which broke under NitrOS-9 v1.22

          This corrected version will work properly under ANY version
          of OS-9 or NitrOS-9, past, present, or future.

          NitrOS-9 Level III patches by request of Erik Tromp, thanks!

  WInfo - v1.0 copyright December,1987 by Ron Lammardo
          Placed in the Public Domain December,1987
          This subroutine may not be sold or used in any commercial package
          without the permission of the author.

WInfo is an OS9 Level II subroutine to return window information on any
window in use. Although WInfo is written in ASM, it is set up to be callable
from an ASM, Basic09, and (hopefully) C main programs. This subroutine directly
accesses system window tables, screen tables, and device memory. As such, if a
new level/version of OS9 were to be released, the subroutine module would
possibly need to be re-written. However, by putting all the 'cheating' code
into this subroutine, any applications program calling it would not need
modification or re-assembling. To further ensure upward compatability between 
editions of WInfo, a sizable amount of space is allocated in the return buffer 
to allow additional fields to be added without impacting the position of 
existing fields.

 WInfo requires two parameters : a string containing the requested device
name, and a return buffer (described below) to place the information into. To
maintain compatability with basic09, the sizes of these two parameters along
with the parameter count (always 2) must be passed if the calling program is
ASM. WInfo also requires 512 bytes for its own use...ASM calling programs 
should allow at least that much buffer space just below the stack address at
the time of call.

If WInfo encounters a system-type error, it will return with the carry bit
set and the b register containing the appropriate error code. If a WInfo error
condition is encountered, the first byte of the return buffer (WI$Stat) will
contain the error number and the error message will be returned at the end of
the buffer (WI$ErMsg). If the length of the buffer passed to WInfo is too
small, the error status returned (WI$Stat) will be $FF with no error message,
as the error message is normally placed at the end of the return buffer. 

WInfo also returns its edition # (the byte after the module name) as part of
the return packet (WI$Edtn). This edition # can be checked to determine if the
correct minimum level of WInfo is being accessed by the main program. For
example, if WInfo edition #4 is the first edition to return the # of users
accessing a window, the main program could check the edition # to insure it
was accessing WInfo edition #4 or higher, as any earlier edition would not
return the needed information.

Most of the return packet fields are self-explanitory, but a few might need 
further clarification.

WI$BPR - bytes per row. This is the number of bytes making up a line of
         charactrers, not the number of bytes in 1 dot row. To get the number
         of bytes per dot row,divide by 8.

WI$Lset- Logic set # - see OS9 Level II manual page 3-21 in the winows section.

WI$VDG - VDG type screen indicator. The following values are possible:
    0 = Non-vdg type screen 
    1 = VDG text type screen
    2 = VDG medium-res (coco2) graphics screen - WI$Sty contains the screen
        mode in the first 4 bits and the foreground color in the last 4 bits.
        The modes and colors are fully described in the OS9 Level-II manual
        pages B-5 & B-6 of the command reference.
    3 = VDG hi-res (coco3) graphics screen - WI$Sty contains the screen type as
        defined in the SS.AScrn Set Status call. This is the only VDG code
        which will return valid palette information (WI$PRegs).

        The following fields are never valid for VDG type screens:

           WI$CBsw  - character binary switch bits
           WI$BDPRN - Border palette register number
           WI$FGPRN - Foreground palette register number
           WI$BGPRN - Background palette register number
           WI$Lset  - Logic set number
           WI$FntGr - Active font group number
           WI$FntBf - Active font buffer number
           WI$PstGr - Pattern set group number
           WI$PstBf - Pattern set buffer number
           WI$GcrGr - Gfx cursor group number
           WI$GcrBf - Gfx cursor buffer number
           WI$DrCrx - Draw cursor x position
           WI$DrCry - Draw cursor y position


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This subroutine is available for use by any and all for whatever application.
Comments and suggestions for improvements/enhancements are greatly appreciated.
However,due to the nature of the subroutine I would appreciate retaining
control of any update issuances so that the edition numbers etc. stay
controlled.

Ron Lammardo
75706,336