How to insert Greek with "ascii keyboard" and XeTeX, Polyglossia
I get satisfying results by converting this asciitogreek.map file
; TECkit mapping for ASCII Greek <-> Unicode characters
LHSName "TeX-text"
RHSName "UNICODE"
pass(Unicode)
; Class "letter" consists of letters and characters denoting accents
; in order to cope with "sigma finalis", i.e., A-Z a-z ` ' > < ~
; we don't need the double quote because it goes only after a vowel
UniClass[letter] = ( U+0041..U+005A U+0061..U+007A U+0060 U+0027 U+003E U+003C U+007E )
; ligatures from Knuth's original CMR fonts
U+002D U+002D <> U+2013 ; -- -> en dash
U+002D U+002D U+002D <> U+2014 ; --- -> em dash
; Greek (according to C. Beccari conventions)
; (-1)
U+0022 <> U+2019 ; APOSTROPHE
U+0060 U+0060 <> U+201C ; `` -> LEFT DOUBLE QUOTATION MARK
U+0027 U+0027 <> U+201D ; '' -> RIGHT DOUBLE QUOTATION MARK
U+003C U+003C <> U+00AB ; << -> LEFT-POINTING DOUBLE ANGLE QUOTATION MARK
U+003E U+003E <> U+00BB ; >> -> RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK
U+0028 U+0028 <> U+00AB ; (( -> LEFT-POINTING DOUBLE ANGLE QUOTATION MARK
U+0029 U+0029 <> U+00BB ; )) -> RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK
; (0) basic letters
; uppercase
U+0041 <> U+0391
U+0042 <> U+0392
U+0044 <> U+0394
U+0045 <> U+0395
U+0046 <> U+03A6
U+0047 <> U+0393
U+0048 <> U+0397
U+0049 <> U+0399
U+004A <> U+0398
U+004B <> U+039A
U+004C <> U+039B
U+004D <> U+039C
U+004E <> U+039D
U+004F <> U+039F
U+0050 <> U+03A0
U+0051 <> U+03A7
U+0052 <> U+03A1
U+0053 <> U+03A3
U+0054 <> U+03A4
U+0055 <> U+03A5
U+0057 <> U+03A9
U+0058 <> U+039E
U+0059 <> U+03A8
U+005A <> U+0396
; lowercase
U+0061 <> U+03B1
U+0062 <> U+03B2
U+0063 <> U+03C2
U+0064 <> U+03B4
U+0065 <> U+03B5
U+0066 <> U+03C6
U+0067 <> U+03B3
U+0068 <> U+03B7
U+0069 <> U+03B9
U+006A <> U+03B8
U+006B <> U+03BA
U+006C <> U+03BB
U+006D <> U+03BC
U+006E <> U+03BD
U+006F <> U+03BF
U+0070 <> U+03C0
U+0071 <> U+03C7
U+0072 <> U+03C1
U+0073 <> U+03C3
U+0073 / _ ^[letter] <> U+03C2
U+0074 <> U+03C4
U+0075 <> U+03C5
U+0077 <> U+03C9
U+0078 <> U+03BE
U+0079 <> U+03C8
U+007A <> U+03B6
; (1) ` + letter -> varia
U+0060 U+0041 <> U+1FBA
U+0060 U+0061 <> U+1F70
U+0060 U+0045 <> U+1FC8
U+0060 U+0065 <> U+1F72
U+0060 U+0048 <> U+1FCA
U+0060 U+0068 <> U+1F74
U+0060 U+0049 <> U+1FDA
U+0060 U+0069 <> U+1F76
U+0060 U+004F <> U+1FF8
U+0060 U+006F <> U+1F78
U+0060 U+0055 <> U+1FEA
U+0060 U+0075 <> U+1F7A
U+0060 U+0057 <> U+1FFA
U+0060 U+0077 <> U+1F7C
; (2) ' + letter -> oxia
U+0027 U+0041 <> U+1FBB
U+0027 U+0061 <> U+1F71
U+0027 U+0045 <> U+1FC9
U+0027 U+0065 <> U+1F73
U+0027 U+0048 <> U+1FCB
U+0027 U+0068 <> U+1F75
U+0027 U+0049 <> U+1FDB
U+0027 U+0069 <> U+1F77
U+0027 U+004F <> U+1FF9
U+0027 U+006F <> U+1F79
U+0027 U+0055 <> U+1FEB
U+0027 U+0075 <> U+1F7B
U+0027 U+0057 <> U+1FFB
U+0027 U+0077 <> U+1F7D
; (3) > + letter -> psili
U+003E U+0041 <> U+1F08
U+003E U+0061 <> U+1F00
U+003E U+0045 <> U+1F18
U+003E U+0065 <> U+1F10
U+003E U+0048 <> U+1F28
U+003E U+0068 <> U+1F20
U+003E U+0049 <> U+1F38
U+003E U+0069 <> U+1F30
U+003E U+004F <> U+1F48
U+003E U+006F <> U+1F40
U+003E U+0055 <> U+1FBF U+03A5
U+003E U+0075 <> U+1F50
U+003E U+0057 <> U+1F68
U+003E U+0077 <> U+1F60
; (4) < + letter -> dasia
U+003C U+0041 <> U+1F09
U+003C U+0061 <> U+1F01
U+003C U+0045 <> U+1F19
U+003C U+0065 <> U+1F11
U+003C U+0048 <> U+1F29
U+003C U+0068 <> U+1F21
U+003C U+0049 <> U+1F39
U+003C U+0069 <> U+1F31
U+003C U+004F <> U+1F49
U+003C U+006F <> U+1F41
U+003C U+0055 <> U+1F59
U+003C U+0075 <> U+1F51
U+003C U+0057 <> U+1F69
U+003C U+0077 <> U+1F61
; (5) >` + letter -> psili and varia
U+003E U+0060 U+0041 <> U+1F0A
U+003E U+0060 U+0061 <> U+1F02
U+003E U+0060 U+0045 <> U+1F1A
U+003E U+0060 U+0065 <> U+1F12
U+003E U+0060 U+0048 <> U+1F2A
U+003E U+0060 U+0068 <> U+1F22
U+003E U+0060 U+0049 <> U+1F3A
U+003E U+0060 U+0069 <> U+1F32
U+003E U+0060 U+004F <> U+1F4A
U+003E U+0060 U+006F <> U+1F42
U+003E U+0060 U+0055 <> U+1FCD U+03A5
U+003E U+0060 U+0075 <> U+1F52
U+003E U+0060 U+0057 <> U+1F6A
U+003E U+0060 U+0077 <> U+1F62
; (6) `> + letter -> psili and varia
U+0060 U+003E U+0041 <> U+1F0A
U+0060 U+003E U+0061 <> U+1F02
U+0060 U+003E U+0045 <> U+1F1A
U+0060 U+003E U+0065 <> U+1F12
U+0060 U+003E U+0048 <> U+1F2A
U+0060 U+003E U+0068 <> U+1F22
U+0060 U+003E U+0049 <> U+1F3A
U+0060 U+003E U+0069 <> U+1F32
U+0060 U+003E U+004F <> U+1F4A
U+0060 U+003E U+006F <> U+1F42
U+0060 U+003E U+0055 <> U+1FCD U+03A5
U+0060 U+003E U+0075 <> U+1F52
U+0060 U+003E U+0057 <> U+1F6A
U+0060 U+003E U+0077 <> U+1F62
; (7) >' + letter -> psili and oxia
U+003E U+0027 U+0041 <> U+1F0C
U+003E U+0027 U+0061 <> U+1F04
U+003E U+0027 U+0045 <> U+1F1C
U+003E U+0027 U+0065 <> U+1F14
U+003E U+0027 U+0048 <> U+1F2C
U+003E U+0027 U+0068 <> U+1F24
U+003E U+0027 U+0049 <> U+1F3C
U+003E U+0027 U+0069 <> U+1F34
U+003E U+0027 U+004F <> U+1F4C
U+003E U+0027 U+006F <> U+1F44
U+003E U+0027 U+0055 <> U+1FCE U+03A5
U+003E U+0027 U+0075 <> U+1F54
U+003E U+0027 U+0057 <> U+1F6C
U+003E U+0027 U+0077 <> U+1F64
; (8) '> + letter -> psili and oxia
U+0027 U+003E U+0041 <> U+1F0C
U+0027 U+003E U+0061 <> U+1F04
U+0027 U+003E U+0045 <> U+1F1C
U+0027 U+003E U+0065 <> U+1F14
U+0027 U+003E U+0048 <> U+1F2C
U+0027 U+003E U+0068 <> U+1F24
U+0027 U+003E U+0049 <> U+1F3C
U+0027 U+003E U+0069 <> U+1F34
U+0027 U+003E U+004F <> U+1F4C
U+0027 U+003E U+006F <> U+1F44
U+0027 U+003E U+0055 <> U+1FCE U+03A5
U+0027 U+003E U+0075 <> U+1F54
U+0027 U+003E U+0057 <> U+1F6C
U+0027 U+003E U+0077 <> U+1F64
; (9) <` + letter -> dasia and varia
U+003C U+0060 U+0041 <> U+1F0B
U+003C U+0060 U+0061 <> U+1F03
U+003C U+0060 U+0045 <> U+1F1B
U+003C U+0060 U+0065 <> U+1F13
U+003C U+0060 U+0048 <> U+1F2B
U+003C U+0060 U+0068 <> U+1F23
U+003C U+0060 U+0049 <> U+1F3B
U+003C U+0060 U+0069 <> U+1F33
U+003C U+0060 U+004F <> U+1F4B
U+003C U+0060 U+006F <> U+1F43
U+003C U+0060 U+0055 <> U+1F5B
U+003C U+0060 U+0075 <> U+1F53
U+003C U+0060 U+0057 <> U+1F6B
U+003C U+0060 U+0077 <> U+1F63
; (10) `< + letter -> dasia and varia
U+0060 U+003C U+0041 <> U+1F0B
U+0060 U+003C U+0061 <> U+1F03
U+0060 U+003C U+0045 <> U+1F1B
U+0060 U+003C U+0065 <> U+1F13
U+0060 U+003C U+0048 <> U+1F2B
U+0060 U+003C U+0068 <> U+1F23
U+0060 U+003C U+0049 <> U+1F3B
U+0060 U+003C U+0069 <> U+1F33
U+0060 U+003C U+004F <> U+1F4B
U+0060 U+003C U+006F <> U+1F43
U+0060 U+003C U+0055 <> U+1F5B
U+0060 U+003C U+0075 <> U+1F53
U+0060 U+003C U+0057 <> U+1F6B
U+0060 U+003C U+0077 <> U+1F63
; (11) ~ + letter -> perispomeni
U+007E U+0041 <> U+0391 U+0342
U+007E U+0061 <> U+1FB6
U+007E U+0048 <> U+0397 U+0342
U+007E U+0068 <> U+1FC6
U+007E U+0049 <> U+0399 U+0342
U+007E U+0069 <> U+1FD6
U+007E U+0055 <> U+03A5 U+0342
U+007E U+0075 <> U+1FE6
U+007E U+0057 <> U+03A9 U+0342
U+007E U+0077 <> U+1FF6
; (12) >~ + letter -> psili and perispomeni
U+003E U+007E U+0041 <> U+1F0E
U+003E U+007E U+0061 <> U+1F06
U+003E U+007E U+0048 <> U+1F2E
U+003E U+007E U+0068 <> U+1F26
U+003E U+007E U+0049 <> U+1F3E
U+003E U+007E U+0069 <> U+1F36
U+003E U+007E U+0055 <> U+1FCF U+03A5
U+003E U+007E U+0075 <> U+1F56
U+003E U+007E U+0057 <> U+1F6E
U+003E U+007E U+0077 <> U+1F66
; (13) ~> + letter -> psili and perispomeni
U+007E U+003E U+0041 <> U+1F0E
U+007E U+003E U+0061 <> U+1F06
U+007E U+003E U+0048 <> U+1F2E
U+007E U+003E U+0068 <> U+1F26
U+007E U+003E U+0049 <> U+1F3E
U+007E U+003E U+0069 <> U+1F36
U+007E U+003E U+0055 <> U+1FCF U+03A5
U+007E U+003E U+0075 <> U+1F56
U+007E U+003E U+0057 <> U+1F6E
U+007E U+003E U+0077 <> U+1F66
; (14) <~ + letter -> dasia and perispomeni
U+003C U+007E U+0041 <> U+1F0F
U+003C U+007E U+0061 <> U+1F07
U+003C U+007E U+0048 <> U+1F2F
U+003C U+007E U+0068 <> U+1F27
U+003C U+007E U+0049 <> U+1F3F
U+003C U+007E U+0069 <> U+1F37
U+003C U+007E U+0055 <> U+1F5F
U+003C U+007E U+0075 <> U+1F57
U+003C U+007E U+0057 <> U+1F6F
U+003C U+007E U+0077 <> U+1F67
; (15) ~< + letter -> dasia and perispomeni
U+007E U+003C U+0041 <> U+1F0F
U+007E U+003C U+0061 <> U+1F07
U+007E U+003C U+0048 <> U+1F2F
U+007E U+003C U+0068 <> U+1F27
U+007E U+003C U+0049 <> U+1F3F
U+007E U+003C U+0069 <> U+1F37
U+007E U+003C U+0055 <> U+1F5F
U+007E U+003C U+0075 <> U+1F57
U+007E U+003C U+0057 <> U+1F6F
U+007E U+003C U+0077 <> U+1F67
; (16) letter + | -> ypogegrammeni
U+0041 U+007C <> U+1FBC
U+0061 U+007C <> U+1FB3
U+0048 U+007C <> U+1FCC
U+0068 U+007C <> U+1FC3
U+0057 U+007C <> U+1FFC
U+0077 U+007C <> U+1FF3
; (17) ` + letter + | -> varia and ypogegrammeni
U+0060 U+0061 U+007C <> U+1FB2
U+0060 U+0068 U+007C <> U+1FC2
U+0060 U+0077 U+007C <> U+1FF2
; (18) ' + letter + | -> oxia and ypogegrammeni
U+0027 U+0061 U+007C <> U+1FB2
U+0027 U+0068 U+007C <> U+1FC2
U+0027 U+0077 U+007C <> U+1FF2
; (19) ~ + letter + | -> perispomeni and ypogegrammeni
U+007E U+0061 U+007C <> U+1FB7
U+007E U+0068 U+007C <> U+1FC7
U+007E U+0077 U+007C <> U+1FF7
; (20) > + letter + | -> psili and ypogegrammeni
U+003E U+0041 U+007C <> U+1F88
U+003E U+0061 U+007C <> U+1F80
U+003E U+0048 U+007C <> U+1F98
U+003E U+0068 U+007C <> U+1F90
U+003E U+0057 U+007C <> U+1FA8
U+003E U+0077 U+007C <> U+1FA0
; (21) >` + letter + | -> psili and varia and ypogegrammeni
U+003E U+0060 U+0041 U+007C <> U+1F8A
U+003E U+0060 U+0061 U+007C <> U+1F82
U+003E U+0060 U+0048 U+007C <> U+1F9A
U+003E U+0060 U+0068 U+007C <> U+1F92
U+003E U+0060 U+0057 U+007C <> U+1FAA
U+003E U+0060 U+0077 U+007C <> U+1FA2
; (22) `> + letter + | -> psili and varia and ypogegrammeni
U+0060 U+003E U+0041 U+007C <> U+1F8A
U+0060 U+003E U+0061 U+007C <> U+1F82
U+0060 U+003E U+0048 U+007C <> U+1F9A
U+0060 U+003E U+0068 U+007C <> U+1F92
U+0060 U+003E U+0057 U+007C <> U+1FAA
U+0060 U+003E U+0077 U+007C <> U+1FA2
; (23) >' + letter + | -> psili and oxia and ypogegrammeni
U+003E U+0027 U+0041 U+007C <> U+1F8C
U+003E U+0027 U+0061 U+007C <> U+1F84
U+003E U+0027 U+0048 U+007C <> U+1F9C
U+003E U+0027 U+0068 U+007C <> U+1F94
U+003E U+0027 U+0057 U+007C <> U+1FAC
U+003E U+0027 U+0077 U+007C <> U+1FA4
; (24) '> + letter + | -> psili and oxia and ypogegrammeni
U+0027 U+003E U+0041 U+007C <> U+1F8C
U+0027 U+003E U+0061 U+007C <> U+1F84
U+0027 U+003E U+0048 U+007C <> U+1F9C
U+0027 U+003E U+0068 U+007C <> U+1F94
U+0027 U+003E U+0057 U+007C <> U+1FAC
U+0027 U+003E U+0077 U+007C <> U+1FA4
; (25) < + letter + | -> dasia and ypogegrammeni
U+003C U+0041 U+007C <> U+1F89
U+003C U+0061 U+007C <> U+1F81
U+003C U+0048 U+007C <> U+1F99
U+003C U+0068 U+007C <> U+1F91
U+003C U+0057 U+007C <> U+1FA9
U+003C U+0077 U+007C <> U+1FA1
; (26) <` + letter + | -> dasia and varia and ypogegrammeni
U+003C U+0060 U+0041 U+007C <> U+1F8B
U+003C U+0060 U+0061 U+007C <> U+1F83
U+003C U+0060 U+0048 U+007C <> U+1F9B
U+003C U+0060 U+0068 U+007C <> U+1F93
U+003C U+0060 U+0057 U+007C <> U+1FAB
U+003C U+0060 U+0077 U+007C <> U+1FA3
; (27) `< + letter + | -> dasia and varia and ypogegrammeni
U+0060 U+003C U+0041 U+007C <> U+1F8B
U+0060 U+003C U+0061 U+007C <> U+1F83
U+0060 U+003C U+0048 U+007C <> U+1F9B
U+0060 U+003C U+0068 U+007C <> U+1F93
U+0060 U+003C U+0057 U+007C <> U+1FAB
U+0060 U+003C U+0077 U+007C <> U+1FA3
; (28) <' + letter + | -> dasia and oxia and ypogegrammeni
U+003C U+0027 U+0041 U+007C <> U+1F8D
U+003C U+0027 U+0061 U+007C <> U+1F85
U+003C U+0027 U+0048 U+007C <> U+1F9D
U+003C U+0027 U+0068 U+007C <> U+1F95
U+003C U+0027 U+0057 U+007C <> U+1FAD
U+003C U+0027 U+0077 U+007C <> U+1FA5
; (29) '< + letter + | -> dasia and oxia and ypogegrammeni
U+0027 U+003C U+0041 U+007C <> U+1F8D
U+0027 U+003C U+0061 U+007C <> U+1F85
U+0027 U+003C U+0048 U+007C <> U+1F9D
U+0027 U+003C U+0068 U+007C <> U+1F95
U+0027 U+003C U+0057 U+007C <> U+1FAD
U+0027 U+003C U+0077 U+007C <> U+1FA5
; (30) " + letter -> dialytika
U+0022 U+0049 <> U+03AA
U+0022 U+0069 <> U+03CA
U+0022 U+0055 <> U+03AB
U+0022 U+0075 <> U+03CB
; (31) "' + letter -> dialytika and oxia
U+0022 U+0027 U+0069 <> U+1FD3
U+0022 U+0027 U+0075 <> U+1FE3
; (32) '" + letter -> dialytika and oxia
U+0027 U+0022 U+0069 <> U+1FD3
U+0027 U+0022 U+0075 <> U+1FE3
; (33) "` + letter -> dialytika and varia
U+0022 U+0060 U+0069 <> U+1FD2
U+0022 U+0060 U+0075 <> U+1FE2
; (34) `" + letter -> dialytika and varia
U+0060 U+0022 U+0069 <> U+1FD2
U+0060 U+0022 U+0075 <> U+1FE2
; (35) "~ + letter -> dialytika and perispomeni
U+0022 U+007E U+0069 <> U+1FD7
U+0022 U+007E U+0075 <> U+1FE7
; (36) ~" + letter -> dialytika and perispomeni
U+007E U+0022 U+0069 <> U+1FD7
U+007E U+0022 U+0075 <> U+1FE7
; (37) rho, medial sigma and punctuation
; >r
U+003E U+0072 <> U+1FE4
; <R
U+003C U+0052 <> U+1FEC
; <r
U+003C U+0072 <> U+1FE5
; medial sigma (sv)
U+0073 U+0076 <> U+03C3
; question mark
U+003F <> U+037E
; semicolon
U+003B <> U+0387
with the command
teckit_compile asciitogreek.map
Then the following document
\documentclass[a4paper]{article}
\usepackage{fontspec}
\setmainfont{Tempora LGC Unicode}
% \newfontfamily\greekfont{GFS Neohellenic}
\usepackage{polyglossia}
\setmainlanguage[variant=polytonic]{greek}
\XeTeXinputnormalization=1
\newenvironment{transgreek}
{\catcode`\~=12 \begin{otherlanguage}{greek}%
\addfontfeature{Mapping=asciitogreek}}
{\end{otherlanguage}}
\newenvironment{transgreek*}
{\catcode`\~=12 \begin{otherlanguage*}{greek}%
\addfontfeature{Mapping=asciitogreek}}
{\end{otherlanguage*}}
\newcommand{\texttransgreek}{\begingroup
\catcode`\~=12 \innertexttransgreek}
\newcommand*{\innertexttransgreek}[1]{%
\begin{transgreek*}#1\end{transgreek*}\endgroup}
\begin{document}
\begin{transgreek}
Th| p'anta dido'ush| ka`i
>apolambano'ush| f'usei <o
pepaideum'enos ka`i a>id'hmwn
l'egei; ((d`os, <`o j'eleis,
>ap'olabe, <`o j'eleic)).
L'egei d`e to~uto o>u
katajrasun'omenos, >all`a
peijarq~wn m'onon ka`i
e>uno~wn a>ut~h|.
\end{transgreek}
\texttransgreek{Th| p'anta dido'ush| ka`i
>apolambano'ush| f'usei <o
pepaideum'enos ka`i a>id'hmwn
l'egei; ((d`os, <`o j'eleis,
>ap'olabe, <`o j'eleic)).
L'egei d`e to~uto o>u
katajrasun'omenos, >all`a
peijarq~wn m'onon ka`i
e>uno~wn a>ut~h|.}
\begin{transgreek}
Γ<<tonos>>
``soma''
0
abcdefghijklmnopqrstuvwxyz
ABCDEFGHIJKLMNOPQRSTUVWXYZ
abgdezhjiklmnxoprsctupqyw
ABGDEZHJIKLMNXOPRSTUFQYW
1 (bare~ia) `a `e `h `i `o `u `w `A `E `H `I `O `U `W
2 (>oxe~ia) 'a 'e 'h 'i 'o 'u 'w 'A 'E 'H 'I 'O 'U 'W
3 (das`u pne~uma) >a >e >h >i >o >u >w >A >E >H >I >O >U >W
4 (yil'on pne~uma) <a <e <h <i <o <u <w <A <E <H <I <O <U <W
5 >`a >`e >`h >`i >`o >`u >`w >`A >`E >`H >`I >`O >`U >`W
6 `>a `>e `>h `>i `>o `>u `>w `>A `>E `>H `>I `>O `>U `>W
7 >'a >'e >'h >'i >'o >'u >'w >'A >'E >'H >'I >'O >'U >'W
8 '>a '>e '>h '>i '>o '>u '>w '>A '>E '>H '>I '>O '>U '>W
9 >`a >`e >`h >`i >`o >`u >`w >`A >`E >`H >`I >`O >`U >`W
10 `>a `>e `>h `>i `>o `>u `>w `>A `>E `>H `>I `>O `>U `>W
11 (perispwm'enh) ~a ~h ~i ~u ~w ~A ~H ~I ~U ~W
12 >~a >~h >~i >~u >~w >~A >~H >~I >~U >~W
13 ~>a ~>h ~>i ~>u ~>w ~>A ~>H ~>I ~>U ~>W
14 <~a <~h <~i <~u <~w <~A <~H <~I <~U <~W
15 ~<a ~<h ~<i ~<u ~<w ~<A ~<H ~<I ~<U ~<W
16 a| h| w| A| H| W|
17 `a| `h| `w|
18 'a| 'h| 'w|
19 ~a| ~h| ~w|
20 >a| >h| >w| >A| >H| >W|
21 >`a| >`h| >`w| >`A| >`H| >`W|
22 `>a| `>h| `>w| `>A| `>H| `>W|
23 >'a| >'h| >'w| >'A| >'H| >'W|
24 '>a| '>h| '>w| '>A| '>H| '>W|
25 <a| <h| <w| <A| <H| <W|
26 <`a| <`h| <`w| <`A| <`H| <`W|
27 `<a| `<h| `<w| `<A| `<H| `<W|
28 <'a| <'h| <'w| <'A| <'H| <'W|
29 '<a| '<h| '<w| '<A| '<H| '<W|
30 "i "u "I "U
31 "'i "'u
32 '"i '"u
33 "`i "`u
34 `"i `"u
35 "~i "~u
36 ~"i ~"u
37 >r <R <r sv s" ? ;
\end{transgreek}
\end{document}
will show that the transliterization works according with the babel conventions.
If you have only a few greek chars you want to enter you can also use the ^^^^+unicode notation. E.g. for an alpha:
\documentclass{article}
\usepackage{fontspec}
\setmainfont{Arial}
\begin{document}
^^^^03b1
\end{document}
If you’re using GNU/Linux, the Hellenic Polytonic HOWTO (tlgu.carmen.gr/Hellenic_polytonic_HOWTO.html) will be invaluable to you. Note, however, that some of the instructions need updating: at least on Debian systems, one now edits /etc/default/keyboard rather than XF86Config.