======**sqInt ioHasDisplayDepth(sqInt depth)**======

**Parms**: depth, integer indicating proposed depth
**return**:  true or false, true if the given depth is supported, false otherwise
**From**: Interpreter
**Why**: 
To find out what the system supports, really we want to know if we can make a 32 bit or 16bit form

**Responsibility**:
Work with the window system to indicate what depth is supported. 
Windows returns negative numbers for LSB based display systems. 

**MacIntosh**
//os-9/OSXCarbon//
The carbon VM returns true for 1,2,4,8,16,32 bits
Earlier versions of the carbon VM would only return true for  8,16,32 bits

//Cocoa://
We lie. 32 bits is only supported, other depths are pending

**iPhone**
32 bits only

**Unix**
16, 32 is supported, 1,2,4,8 could be supported

**Windows**
1,4,8,16,32 for MSB
LSB returns -8, -16, -32 

**BUGS**
returning negative values for LSB based display systems is not supported on most platforms.