When I was at Worcester Polytech, I wrote a program for a class in comptuer graphics which used the VT11/VR14 (on an 11/40) to design simple logic circuits. There was a library of simple gates along one side of the screen and one used the light pen to drag a part onto the design grid and place it in position. Once all the parts were on the grid, the inputs and outputs could be connected. And there was a special input for a clocking signal, and other inputs were supplied from the front panel switches. The state of the gates was displayed in table form on screen and one could watch as the circuit operated. Pretty simple stuff, compared with *real* cad work... but it was fun, and get me a good grade (and actually got me graphics work with other departments at WPI) Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+