00h successful
		DL = current switch character
	    FFh unsupported subfunction
Desc:	Determine the character which is used to introduce command switches.
	  This setting is ignored by MS-DOS commands in version 4.0 and higher,
	  but is honored by many third-party programs and by Novell DOS 7
	  external commands
BUG:	Novell DOS 7's COMMAND.COM (prior to Update 15) fails to honor the
	  SwitChar setting for internal commands even though COMMAND.COM
	  honors it in its own command tail (i.e. COMMAND /?); even in Update
	  15, internal commands fail to honor SwitChar for the /? help option
Notes:	documented in some OEM versions of some releases of DOS
	supported by OS/2 compatibility box
	always returns AL=00h/DL=2Fh for MS-DOS 5+ and DR DOS 3.41-6.0
	Novell DOS 7 COMMAND.COM indicates switch characters other than '/'
	  by changing the first backslash (and only the first one) in the
	  path it prints for PROMPT $p with a forward slash
SeeAlso: AX=3701h
--------D-213701-----------------------------
INT 21 - DOS 2+ - "SWITCHAR" - SET SWITCH CHARACTER
	AX = 3701h
	DL = new switch character
Return: AL = status
	    00h successful
	    FFh unsupported subfunction
Notes:	documented in some OEM versions of some releases of DOS; DOS 2.x had
	  a SWITCHAR=c setting in CONFIG.SYS
	supported by OS/2 compatibility box and Novell DOS 7
	ignored by MS-DOS 5+ and DR DOS 3.41-6.0; DR DOS 6.0 and Novell DOS 7
	  leave AX unchanged
SeeAlso: AX=3700h
--------D-2137-------------------------------
INT 21 - DOS 2.x and 3.3+ only - "AVAILDEV" - SPECIFY \DEV\ PREFIX USE
	AH = 37h
	AL = subfunction
	    02h get availdev flag
		Return: DL = 00h \DEV\ must precede character device names
			   = nonzero \DEV\ is optional
	    03h set availdev flag
		DL = new state
		    00h		\DEV\ is mandatory
		    nonzero	\DEV\ is optional
Return: AL = status
	    00h successful
	    FFh unsupported subfunction
Notes:	all versions of DOS from 2.00 allow \DEV\ to be prepended to device
	  names without generating an error even if the directory \DEV does
	  not actually exist (other paths generate an error if they do not
	  exist); DOS 2.x has an AVAILDEV= option in CONFIG.SYS to make \DEV
	  mandatory
	although MS-DOS 3.3+, DR DOS 3.41+, and Novell DOS 7 accept these
	  calls, they have no effect, and AL=02h always returns DL=FFh (except
	  for Novell DOS 7, which leaves AX unchanged for both subfunctions)
--------D-2138-------------------------------
INT 21 - DOS 2+ - GET COUNTRY-SPECIFIC INFORMATION
	AH = 38h
--DOS 2.x--
	AL = 00h get current-country info
	DS:DX -> buffer for returned info (see #1263,#1264)
Return: CF set on error
	    AX = error code (02h)
	CF clear if successful
	    AX = country code (MS-DOS 2.11 only)
	    buffer at DS:DX filled
--DOS 3.0+--
	AL = 00h for current country
	AL = 01h thru 0FEh for specific country with code <255 (see #1265)
	AL = 0FFh for specific country with code >= 255
	   BX = 16-bit country code (see #1265)
	DS:DX -> buffer for returned info (see #1264)
Return: CF set on error
	    AX = error code (02h)
	CF clear if successful
	    AX = country code (Novell NWDOS v7.0)
	    BX = country code
	    DS:DX buffer filled
Note:	this function is not supported by the Borland DPMI host, but no error
	  is returned; as a workaround, one should allocate a buffer in
	  conventional memory with INT 31/AX=0100h and simulate an INT 21 with
	  INT 31/AX=0300h
SeeAlso: AH=65h,INT 10/AX=5001h,INT 2F/AX=110Ch,INT 2F/AX=1404h

Format of DOS 2.00-2.10 country info:
Offset	Size	Description	(Table 1263)
 00h	WORD	date format  0 = USA	mm dd yy
			     1 = Europe dd mm yy
			     2 = Japan	yy mm dd
 02h	BYTE	currency symbol
 03h	BYTE	00h
 04h	BYTE	thousands separator char
 05h	BYTE	00h
 06h	BYTE	decimal separator char
 07h	BYTE	00h
 08h 24 BYTEs	reserved

Format of DOS 2.11+ country info:
Offset	Size	Description	(Table 1264)
 00h	WORD	date format (see #1263)
 02h  5 BYTEs	ASCIZ currency symbol string
 07h  2 BYTEs	ASCIZ thousands separator
 09h  2 BYTEs	ASCIZ decimal separator
 0Bh  2 BYTEs	ASCIZ date separator
 0Dh  2 BYTEs	ASCIZ time separator
 0Fh	BYTE	currency format
		bit 2 = set if currency symbol replaces decimal point
		bit 1 = number of spaces between value and currency symbol
		bit 0 = 0 if currency symbol precedes value
			1 if currency symbol follows value
 10h	BYTE	number of digits after decimal in currency
 11h	BYTE	time format
		bit 0 = 0 if 12-hour clock
			1 if 24-hour clock
 12h	DWORD	address of case map routine
		(FAR CALL, AL = character to map to upper case [>= 80h])
 16h  2 BYTEs	ASCIZ data-list separator
 18h 10 BYTEs	reserved

(Table 1265)
Values for country code:
 001h (1)	United States
 002h (2)	Canadian-French
 003h (3)	Latin America
 004h (4)	Canada (English)
 007h (7)	Russia
 014h (20)	Egypt
 01Bh (27)	South Africa
 01Eh (30)	Greece
 01Fh (31)	Netherlands
 020h (32)	Belgium
 021h (33)	France
 022h (34)	Spain
 023h (35)	Bulgaria???
 024h (36)	Hungary (not supported by DR DOS 5.0)
 026h (38)	Yugoslavia (not supported by DR DOS 5.0) -- obsolete
 027h (39)	Italy / San Marino / Vatican City
 028h (40)	Romania
 029h (41)	Switzerland / Liechtenstein
 02Ah (42)	Czechoslovakia / Tjekia / Slovakia (not supported by DR DOS 5.0)
 02Bh (43)	Austria (DR DOS 5.0)
 02Ch (44)	United Kingdom
 02Dh (45)	Denmark
 02Eh (46)	Sweden
 02Fh (47)	Norway
 030h (48)	Poland (not supported by DR DOS 5.0)
 031h (49)	Germany
 033h (51)	Peru
 034h (52)	Mexico
 035h (53)	Cuba
 036h (54)	Argentina
 037h (55)	Brazil (not supported by DR DOS 5.0)
 038h (56)	Chile
 039h (57)	Columbia
 03Ah (58)	Venezuela
 03Ch (60)	Malaysia
 03Dh (61)	International English / Australia
 03Eh (62)	Indonesia / East Timor
 03Fh (63)	Philippines
 040h (64)	New Zealand
 041h (65)	Singapore
 042h (66)	Taiwan???
 051h (81)	Japan (DR DOS 5.0, MS-DOS 5.0+)
 052h (82)	South Korea (DR DOS 5.0)
 054h (84)	Vietnam
 056h (86)	China (MS-DOS 5.0+)
 058h (88)	Taiwan (MS-DOS 5.0+)
 05Ah (90)	Turkey (MS-DOS 5.0+)
 05Bh (91)	India
 05Ch (92)	Pakistan
 05Dh (93)	Afghanistan
 05Eh (94)	Sri Lanka
 062h (98)	Iran
 063h (99)	Asia (English)
 070h (112)	Belarus
 0C8h (200)	Thailand
 0D4h (212)	Morocco
 0D5h (213)	Algeria
 0D8h (216)	Tunisia
 0DAh (218)	Libya
 0DCh (220)	Gambia
 0DDh (221)	Senegal
 0DEh (222)	Maruitania
 0DFh (223)	Mali
 0E0h (224)	African Guinea
 0E1h (225)	Ivory Coast
 0E2h (226)	Burkina Faso
 0E3h (227)	Niger
 0E4h (228)	Togo
 0E5h (229)	Benin
 0E6h (230)	Mauritius
 0E7h (231)	Liberia
 0E8h (232)	Sierra Leone
 0E9h (233)	Ghana
 0EAh (234)	Nigeria
 0EBh (235)	Chad
 0ECh (236)	Centra African Republic
 0EDh (237)	Cameroon
 0EEh (238)	Cape Verde Islands
 0EFh (239)	Sao Tome and Principe
 0F0h (240)	Equatorial Guinea
 0F1h (241)	Gabon
 0F2h (242)	Congo
 0F3h (243)	Zaire
 0F4h (244)	Angola
 0F5h (245)	Guinea-Bissau
 0F6h (246)	Diego Garcia
 0F7h (247)	Ascension Isle
 0F8h (248)	Seychelles
 0F9h (249)	Sudan
 0FAh (250)	Rwhanda
 0FBh (251)	Ethiopia
 0FCh (252)	Somalia
 0FDh (253)	Djibouti
 0FEh (254)	Kenya
 0FFh (255)	Tanzania
 100h (256)	Uganda
 101h (257)	Burundi
 103h (259)	Mozambique
 104h (260)	Zambia
 105h (261)	Madagascar
 106h (262)	Reunion Island
 107h (263)	Zimbabwe
 108h (264)	Namibia
 109h (265)	Malawi
 10Ah (266)	Lesotho
 10Bh (267)	Botswana
 10Ch (268)	Swaziland
 10Dh (269)	Comoros
 10Eh (270)	Mayotte
 122h (290)	St. Helena
 129h (297)	Aruba
 12Ah (298)	Faroe Islands
 12Bh (299)	Greenland
 15Eh (350)	Gibraltar
 15Fh (351)	Portugal
 160h (352)	Luxembourg
 161h (353)	Ireland
 162h (354)	Iceland
 163h (355)	Albania
 164h (356)	Malta
 165h (357)	Cyprus
 166h (358)	Finland
 167h (359)	Bulgaria
 172h (370)	Lithuania
 173h (371)	Latvia
 174h (372)	Estonia
 175h (373)	Moldova
 17Dh (381)	Serbia / Montenegro
 180h (384)	Croatia???
 181h (385)	Croatia
 182h (386)	Slovenia
 183h (387)	Bosnia-Herzegovina (Latin)
 184h (388)	Bosnia-Herzegovina (Cyrillic)
 185h (389)	FYR Macedonia
 1A5h (421)	Czech Republic
 1A6h (422)	Slovakia
 1F4h (500)	Falkland Islands
 1F5h (501)	Belize
 1F6h (502)	Guatemala
 1F7h (503)	El Salvador
 1F8h (504)	Honduras
 1F9h (505)	Nicraragua
 1FAh (506)	Costa Rica
 1FBh (507)	Panama
 1FCh (508)	St. Pierre and Miquelon
 1FDh (509)	Haiti
 24Eh (590)	Guadeloupe
 24Fh (591)	Bolivia
 250h (592)	Guyana
 251h (593)	Ecuador
 252h (594)	rench Guiana
 253h (595)	Paraguay
 254h (596)	Martinique / French Antilles
 255h (597)	Suriname
 256h (598)	Uruguay
 257h (599)	Netherland Antilles
 29Eh (670)	Saipan / N. Mariana Island
 29Fh (671)	Guam
 2A0h (672)	Norfolk Island (Australia) / Christmas Island/Cocos Islands / Antartica
 2A1h (673)	Brunei Darussalam
 2A2h (674)	Nauru
 2A3h (675)	Papua New Guinea
 2A4h (676)	Tonga Islands
 2A5h (677)	Solomon Islands
 2A6h (678)	Vanuatu
 2A7h (679)	Fiji
 2A8h (680)	Palau
 2A9h (681)	Wallis & Futuna
 2AAh (682)	Cook Islands
 2ABh (683)	Niue
 2ACh (684)	American Samoa
 2ADh (685)	Western Samoa
 2AEh (686)	Kiribati
 2AFh (687)	New Caledonia
 2B0h (688)	Tuvalu
 2B1h (689)	French Polynesia
 2B2h (690)	Tokealu
 2B3h (691)	Micronesia
 2B4h (692)	Marshall Islands
 2C7h (711)	??? (currency = EA$)
 311h (785)	Arabic (Middle East/Saudi Arabia/etc.)
 324h (804)	Ukraine
 329h (809)	Antigua and Barbuda / Anguilla / Bahamas / Barbados / Bermuda
		British Virgin Islands / Cayman Islands / Dominica
		Dominican Republic / Grenada / Jamaica / Montserra
		St. Kitts and Nevis / St. Lucia / St. Vincent and Grenadines
		Trinidad and Tobago / Turks and Caicos
 352h (850)	North Korea
 354h (852)	Hong Kong
 355h (853)	Macao
 357h (855)	Cambodia
 358h (856)	Laos
 370h (880)	Bangladesh
 376h (886)	Taiw