INT 2fH 4a11H BX=0000H: Get Dblspace Version & Drives
Expects: AX 4a11H (mux number)
BX 0000H (DoubleSpace fn code)
Returns: AX DoubleSpace API Error Code (0000H=success)
BX 444dH signature; 'M','D')
CL first drive letter used by DoubleSpace (41H='A', etc.)
CH count of drives letters used by DoubleSpace
DX Version number (an internal code) high bit indicates current
code location (high or low memory)
Info: You may use this fn to see if DoubleSpace is installed and to
obtain the range of drive letters that it uses.
CL is the ASCII code for a drive letter (for instance, 45H=E).
CH is a count of how many drive IDs are controlled by DoubleSpace;
for instance, CX=0544H means drives D,E,F,G, and H are available
to DoubleSpace for use as drive IDs.
DX The low 15 bits identify the version number (this shows up as
0006H on my PC).
Bit 15 is a location flag: When set, it indicates that
DBLSPACE.BIN is not at its final location (for instance, the
DEVICEHIGH=DBLSPACE.SYS command is not in CONFIG.SYS or has not
been executed yet.
See Also: DoubleSpace Overview
INT 2fH: Multiplex Interrupt