INT 2F - DOS 3.3+ PRINT.COM - GET PRINTER DEVICE
        AX = 0106h
Return: CF set if files in print queue
            AX = error code 0008h (queue full)
            DS:SI -> device driver header
        CF clear if print queue empty
            AX = 0000h
Desc:   determine which device, if any, PRINT is currently using for output
Notes:  documented for DOS 5+, but not documented for prior versions
        this function can be used to allow a program to avoid printing to the
          printer on which PRINT is currently performing output
SeeAlso: AX=0104h

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