devices of sunnyvale calif several other conventional components are connected to microprocessor 38 including a clock 40 backup battery 42 dynamic random access memory dram 44 for temporary data storage during program execution preferably at least one megabyte and read only memory rom 46 for permanently storing the basic input an output system bios software additional rom 48 may optionally be provided to store conventional operating system software including pc dos ms dos os 2 and macintosh operating systems computer 36 may include a plurality of expansion slots not shown for receiving circuit boards which add to the computer 39 s functionality for example one of the slots could be occupied by a graphics adaptor such a vga visual graphics adaptor circuit board providing enhanced graphical output for lcd panel 14 rather than providing such a card however these functions have been integrated in the preferred embodiment in the mother board in an lcd vga controller 50 such as the cl gd6410 controller available from cirrus logic of fremont calif this controller can provide output to both an lcd panel and a crt monitor 72 simultaneously lcd panel 14 as well as other peripheral devices are accessed via a controller 54 having a plurality of output ports 56 serial and or parallel represented in fig3 by double arrows a satisfactory controller is the pc87310 controller available from national semiconductor.