MicroCAD Status

      A major change of direction in the MicroCAD project should result in completion of the conversion within the next month. Since we were able to find an excellent C compiler for the 8086, under both PCDOS/MSDOS and CP/M-86, we've decided to convert the SPL code to C rather than port SPL. Keith Marcelius surveyed the available C compilers and decided that the Computer Innovations compiler was the clear choice. We bought two copies of the compiler, and Greg Lutz and John Walker beat on it enough to satisfy themselves that the compiler was sound. John Walker used it to port META as noted above, and converted a set of high-precision mathematical functions to C (the Computer Innovations compiler has full IEEE single and double precision floating point, but having no math functions in the library is delivered free of SIN).

The C is weak in floating point I/O, but since the compiler is supplied with complete source code for the library, and since all the relevant routines are written in C, this is easily remedied. We have found Computer Innovations to be very helpful and easy to work with, and it seems to be an outfit operating in a style very much like our own.

  Greg Lutz and Dan Drake will be converting the SPL code to C. We've purchased a Houston Instruments HI-PAD digitiser which we will hook up to both the Victor and the IBM PC to test MicroCAD. We're currently looking at plotters, and are trying to see if we can work some kind of cooperative marketing deal with Houston Instruments if we use their plotters as well as their digitisers.

Our current plan for MicroCAD is to have a root segment which contains all the device-dependent parts. That segment will load the ``guts'' of the package which will be totally machine-independent. This has the advantage of modularising the package, making it easier to field-configure, and getting the potentially large drivers out of the address space of the package itself (it takes 40000 bytes to hold the screen bit map on the Victor).

  John Walker has undertaken the task of trying to shoehorn MicroCAD onto the 8080. The effort seems worthwhile investigating as the potential market a success would open up is enormous. The effort was initiated as the result of the question ``Have you ever encountered a program you couldn't make fit on any machine?''.