SEQIN-ST and CODFREG: a full screen sequence editor and a codon usage analysis program for the Atari ST.

Introduction. The program SEQIN-ST helps entering and analysing nucleic acid sequences and protein sequences using personal computers of the ATARI ST series. It allows the manual entry and/or the direct entry from a sequencing gel using the graphic mouse. The user decides the entry mode and the layout of the sequence. In check mode the sequence can be entered a second time and is automatically compared with the original sequence. The sequence can directly be analysed for its reading frames, restriction sites, direct and inverted repeats. The program CODFREG calculates codon frequencies of one or more genes either interactively or in batch mode.