HEWLETT-Packard has started shipping its LaserJet 4ML printer, the newest in its line of devices that meets standards set by the United States Environmental Protection Agency. The LaserJet 4ML prints four pages a minute, at 300 dpi, comes with four megabytes of memory and 80 scalable fonts. It can change automatically between Adobe PostScript Level 2 language software and HP's enhanced PCL 5. It can switch between the LocalTalk port and the Bi-Tronics parallel port. When not in use, the printer automatically ''idles'', which uses only seven watts.