C compilers and non-ASCII systems - test-drb@ccmp.vtda.org

31 Jan 2012

At 11:21 AM -0500 1/31/12, Sean Conner wrote:
...
  >     So now I'm wondering---besides Baudot,
6-bit BCD and EBCDIC, is there any
 >other encoding scheme used?  And of Baudot, 6-bit BCD and EBCDIC, are there
 >any systems using those encoding schemes*AND*  have a C compiler available?
 > Not sure what you mean by 6-bit BCD?
For current systems which use a 6-bit character code, the Unisys 
1100/2200 class systems (ClearPath nowadays) use Fieldata as well as 
9-bit ASCII. They have a C compiler.

These machines are 36-bit, so to fit ASCII characters in, they extended 
the characters to 9 bits, fitting 4 "ASCII" characters in a word instead 
of 6 Fieldata characters. It is possible to use all 9 bits which creates 
interesting problems when you need to migrate the code to a different 
architecture. I have come across (ancient but "modernised") applications 
which mix Fieldata and 9-bit ASCII... Also IIRC there is no reasonable 
way to handle Fieldata in Unisys C, so you have to treat Fieldata 
characters as hex or octal values.

/Jonas