Path: utzoo!attcan!uunet!mcsun!ukc!servax0!sundist!peter
From: peter@sundist.essex.ac.uk (Allott P)
Newsgroups: comp.misc
Subject: Re: Looking for information on the RAD-50 standard
Message-ID: <1521@servax0.essex.ac.uk>
Date: 24 Aug 89 12:47:51 GMT
References: <1076@taurus.BITNET>
Sender: news@servax0.essex.ac.uk
Reply-To: peter@essex.ac.uk (Allott P)
Organization: University of Essex, Colchester, UK
Lines: 40

In article <1076@taurus.BITNET> adiro%math.tau.ac.il@CUNYVM.CUNY.EDU (Rosen Adi) writes:
>
> I am looking for information regarding the RAD-50 standard, which is
>apparently a character encoding standard used on old PDP-11 machines.

This bit of code takes a PDP-11 RAD-50 word (16 bits) and generates the
3 ASCII characters that the word represents. Its writen in BCPL (NOT C)
and was designed to run on a DECSystem-10

It should be easy to rewrite the BITOR line to convert the characters
from sixbit to normal ascii (add ascii space) instead of packing in
DECSystem-10 sixbit.

Hope this is of help
-----------------------------------------------------------------------

LET H50(R50) = VALOF
{   LET S,T=VEC 2,0
    FOR I = 0 TO 2 DO
    {   S!(2-I) _ R50 REM #50
        R50/ _ #50
    }
    FOR I = 0 TO 2 DO
    {   SWITCHON S!I INTO
        {   CASE #33:   S!I_#04
                        ENDCASE
            CASE #34:   S!I_#16
                        ENDCASE
            CASE #36 ... #47: S!I-_#16
                        ENDCASE
            CASE 1 ... #32: S!I+_#40
            CASE 0 :    ENDCASE
            DEFAULT:    ERMESS(3,$6"BR5","Bad RADIX50 value",
                            "The RADIX50 value is invalid and cannot be converted to SIXBIT.")
                        ABORT.RUN()
        }
    }
    FOR I = 0 TO 2 DO T BITOR _ S!I << (6*(2-I))
    RESULTIS T
}