The following char sets are supported from Strawberry Prolog:
 

	Long char set name	Short name
0.	Unicode (UTF-8)	UTF-8
1.	Cyrillic (Windows-1251)	Windows-1251
2.	Western European (Windows-1252)	Windows-1252
3.	Greek (Windows-1253)	Windows-1253
4.	Turkish (Windows-1254)	Windows-1254
5.	Hebrew (Windows-1255)	Windows-1255
6.	Arabic (Windows-1256)	Windows-1256
7.	Baltic (Windows-1257)	Windows-1257
8.	Vietnamese (Windows-1258)	Windows-1258
9.	Thai (Windows-874)	Windows-874
10.	Central European (Windows-1250)	Windows-1250
11.	Western European (ISO)	ISO_8859-1
12.	Central European (ISO)	ISO_8859-2
13.	Latin 3 (ISO)	ISO_8859-3
14.	Baltic (ISO)	ISO_8859-4
15.	Cyrillic (ISO)	ISO_8859-5
16.	Arabic (ASMO 708)	ISO_8859-6
17.	Greek (ISO)	ISO_8859-7
18.	Hebrew (ISO-Visual)	ISO_8859-8
19.	Turkish (ISO)	ISO_8859-9
20.	Baltic (DOS)	cp775
21.	Western European (DOS)	cp850
22.	Central European (DOS)	cp852
23.	Turkish (DOS)	cp857
24.	Cyrillic (DOS)	cp866
25.	Greek, Modern (DOS)	cp869
26.	Cyrillic (KOI8-R)	koi8r

You can convert from one char set to another by the function convert_charset.
 

See also:
char_set_name
convert_charset
convert_UTF8_to_local

Look at the example:
char_sets.spj (in folder Examples)