[ This version now updates the screen as it should, but typing is a little slow on older machines. ]
What is this?
MDP-80 is a simulated 8-bit microcomputer/assembler. I started writing this for high school students in order to introduce them to some of the concepts from microprocessors, machine language programming, and assembly language programming. Unfortunately, I no longer have the time to work on it as I would like. It is fully functional, though the assembler is rather slow and disk intensive, not to mention that it (shudder) makes use of an external data file, Assembler.DAT. I have a second version of the assembler that is twice as fast but incomplete (written _after_ my compiler design course!). I doubt I will be able to finish it soon so I am sending this out with the old assembler.
How does it work?
Run the MDP-80 application to use the simulated computer. It is a small computer that has some 14k of RAM and a 2k ROM monitor program written entirely in MDP-8008 machine code. The assembler is a separate program and produces code files that can be loaded into the simulator. It is possible to program the simulator directly and save the memory to a file, but for all but the smallest programs this will be too much work. Read the included simulator and assembler manuals (as either straight TEXT or as PostScript output from LaTeX - the PostScript form is much nicer to read!) to learn how to use the program.
Other stuff...
I _might_ use this again someday, so I am releasing this as Freeware. I retain ALL RIGHTS to this software and it must be distributed as a whole and not for profit. I give permission to copy this software and manuals to other computer networks or bulletin boards, and to disk or CD-ROM based collections of software provided no fee beyond a reasonable duplication fee is applied.
If you do use this software I would like to hear comments about how it performed, etc. As an aside, the simulator is written in Pocket Forth 0.6 by Chris Heilman and the assembler is written in MacMETH Modula-2. Both are freely available on the net from mac.archive.umich.edu in the /mac/development/languages directory. BTW, MDP stands for Maria, David, and Peter, my wife and two sons. Since I started this Paul has come along but MDPP seemed rather silly. The 8008 is an obvious copy from Intel, and if the machine code and microprocessor architecture seems familiar you must have used the Mostek 6502 sometime in the past!
April 1995,
Ronald T. Kneusel
8725 West Burdick Avenue
Milwaukee, WI 53227 USA
(414) 545-7557
Internet: rkneusel@post.its.mcw.edu or kneusel@msupa.pa.msu.edu
N.B. The documentation does not reflect this, but memory locations $204 and $205 contain a constantly changing 16-bit random number, see the code for Guess100 to see how to use it.
