dpmiqb.bas

如何使用QBasic进入32位保护模式

'Program:       DPMIQB.BAS
'               QBASIC Protected Mode Application.
'Interpreter:   QBASIC with machine code
'Author:        Gunther Ilzig
'               CIS:      100775,2275
'               Internet: [e-mail]
'Status:        Freeware

DECLARE SUB Waiting ()
DECLARE SUB ReadCode (mcseg%, mcoff%)
DECLARE FUNCTION CheckDpmi% (udt&)

TYPE DpmiPar                    'UDT for DPMI parameters
  entry AS LONG                 'DPMI entry point
				'offset 0
  flags AS INTEGER              'flag for 32-bit support
				'offset 4
  cpu   AS INTEGER              'processor type
				'offset 6
  major AS INTEGER              'DPMI major version
				'offset 8
  minor AS INTEGER              'DPMI minor version
				'offset 10
  para  AS INTEGER              'number of paragraphs for private
				'DPMI data
				'offset 12
  pseg  AS INTEGER              'segment private Host data area
				'offset 14
  hseg  AS INTEGER              'segment hello string
				'offset 16
  hoff  AS INTEGER              'offset hello string
				'offset 18
END TYPE
DIM dpmi AS DpmiPar             'define the check structure
DIM mc%(400)                    'machine code array
words% = 0                      'number of words for the DPMI Host
eflag% = 0                      'error flag

'----- The string to print in the Protected Mode

hello$ = ""
hello$ = hello$ + CHR$(&HD) + CHR$(&HA)
hello$ = hello$ + " Hello 32-bit Protected Mode World from QBASIC!"
hello$ = hello$ + CHR$(&HD) + CHR$(&HA) + CHR$(&HD) + CHR$(&HA)
hello$ = hello$ + " Please, press any key to continue ..."
hello$ = hello$ + CHR$(&HD) + CHR$(&HA)
hello$ = hello$ + CHR$(&H24)
dpmi.hseg = VARSEG(hello$)      'string segment
dpmi.hoff = SADD(hello$)        'string offset

'----- Code starts here.

CLS                             'clear text screen

'----- Check DPMI support.

IF CheckDpmi%(dpmi.entry) <> 1 THEN
				'DPMI support isn't available
   PRINT
   PRINT " Sorry!"
   PRINT " Your configuration doesn't support DPMI."
   PRINT
   PRINT " This application works only in the following environments:"
   PRINT
   PRINT "