11/3/71 BPPT (V)





11/3/71                                                  BPPT (V)





NAME            binary punched paper tape format



SYNOPSIS        --



DESCRIPTION     Binary paper tape is used to pass and store arbi-

                trary information on paper tape.  The format cho-

                sen has the following features: a) no format of

                the data is assumed.  b) check summing c) zero

                suppression



                The format is as follows:



                Between records, NULL characters are ignored.

                The beginning of the tape is considered between

                records, thus the leader is ignored.



                The first non-null character specifies the type

                and size of the record.  If the character is pos-

                itive (1 to 177), the record is a data record

                consisting of that many characters.  All but the

                last of these characters are data, the last being

                a checksum.  The checksum is calculated such that

                the sum of the entire record is zero mod 256.



                If the first character is negative (200-376) the

                record is a zero suppression record.  It is iden-

                tical to minus that number of zeros of data.  One

                character of checksum follows this negative char-

                acter.  It is the positive of the negative char-

                acter.



                The special case of a record looking like a sin-

                gle zero character suppressed (377;1) causes no

                data transfer, but is the end-of-file indication.



FILES           --



SEE ALSO        lbppt, dbppt



DIAGNOSTICS     --



BUGS            --



OWNER           ken, dmr
squoze.net
