DTMM is a molecular modelling program, allowing molecule synthesis, editing, energy minimisation, manipulation and display on an IBM PC compatible microcomputer.
Minimum System requirements: IBM 386 PC or compatible with a minimum of 4Mb RAM, DOS version 5.0 or higher, 'Microsoft Windows' version 3.1,VGA or SVGA monitor and graphics card, Microsoft MS-DOS standard mouse (or compatible)
What do you get in package? one highly packed 3.5" PC floppy disc containing 1075Kbytes, including some example molecules and fragments, and an A5 spiral bound manual with 170 pages. The manual has an index and a useful list of mostly historical references on molecular modelling. The tutorial section starts with 'Creating alanine and investigating chirality' and ends with 'Building a peptide and using secondary display styles' which continues with an investigation of the docking facility.
Installation: The manual sensibly advises one to make a backup of the original disc and use the backup for installation, which was easy, although it takes a while (I was testing it on a PC486SX 33MHz card in an Acorn StrongARM RISC PC, with 16Mbytes memory in the PC partition). It is clever enough to discover I do not have a math co-processor, which is recommended, especially for those who want to use the energy minimisation features.
File formats: DTMM reads crystal and orthogonal co-ordinate data from ASCII files in a format compatible with the CSSR (Crystal Structure Search and Retrieval) format. Files saved from DTMM can optionally include information on atomic charge and type. Protein Data Bank format files must be converted using the additional utility (Protin) not tested in this review. There is no mention of CIF files. Limits: DTMM allows up to 2700 atoms and bonds without a co-processor which makes it more use in a teaching than a molecular biology research environment.
Hardcopy output: is made via the 'Windows standard printing' devices, it may be monochrome or colour. The usual printing option allows saving to an Encapsulated Postscript (.EPS) file but this is merely a bitmap. The screen may also be saved to the Windows 'clipboard' or as BMP bitmapped files. (An earlier version used to produce real PostScript rather than these bitmaps which use a lot of disk space if you want high resolution; it is a pity this has not been carried over into Version 3.0. 'ATOMS' from Shape Software is still he only PC program I know of which makes 'real' PostScript output files, which have the advantage of small size and you can improve the resolution of your output merely by printing the file on a higher resolution printer. )
Display types:
Conclusions: DTMM itself is aimed at organic molecule synthesis, not at
crystallographic structures. There is no display type showing parts of the
structure as polyhedra, and no example datafiles of lattice structures
supplied. (These may be included with the 'Inorganic' Structure Library
which was not supplied for this review.) Plain DTMM could be used as a
teaching aid for students of organic chemistry to learn about molecular
modelling.
Kate Crennell
June 97