Programming History

Graphics Class Project, written in C and Xlib. This was a 3d->2d polygon projection using (self taught) BSP trees that allowed the user to walk through a virtual Blacksburg, VA. The display was real-time and at least 30 frames per second on Pentium 75 machines, even running over the network! Most of the rest of the class was all "holy cow our project sucks" but I was so excited about mine that they couldn't really get upset.

Also I was using object-oriented methods in C before I knew anything about OOP! Giving object instances automatically generated descriptive names such as "Normal for Cube-face6" or "PolySplit: Temp positive-side points" made debugging very simple because it was easy to see what data a particular matrix was supposed to have. By far the most fun of any assigned project!

MIPS assembler, written in C for (surprise) assemblers class.  This was a complete assembler except for output being in a non-executable format.  Let's face it, a non-optimizing assembler is fairly simple, so I set out to make it high quality and elegant.  The instructions were all specified in a flexible data structure so it could actually assemble many different instruction sets without changing the logic.  The actual assembly was easy since the data structure said where to put bits (say for an address), what  parameters were expected, and etc, instead of using  conditions to determine those. 

Later on in the project the professor added the requirement to support back substitution (identifiers being used before they are defined). This was challenging for some assemblers because the number of bits specifying the address of the label and the position of those bits in the instruction word varied depending on the type of instruction. (one guy sent me an if statement for this from his program that had at least 10 different expressions and'ed and or'ed together!) In my program I simply looked up the instruction type and shifted and or'ed in the bits. Definitely my favorite program from college.

BB, written in C using sockets and termcap (curses was too slow).  This was an internet-based BBS; mail and messages, active menus, author-editable messages, comprehensive user permissions  (turn on/off everything independently like VMS), fast!  All  in an 86K static Ultrix binary!  I was inspired to write it after visiting my brother, also a CS major, at JMU and seeing their campus message board system.  I didn't distribute the completed system because the web had taken over about that time, so polishing off the details would just be wasted effort.

An Ultrix crash program, written in C. I discovered and tracked down a bug with blocking IO in Ultrix while writing a queue program; the queue would block on writing to a file (using the file as a semaphore) and it worked great except that if you hit ctrl-c (or sent any catchable signal) while it was blocked the entire OS would crash with a "CPU0 panic". I was really excited about discovering such a huge bug and reported it through the proper channels. Supposedly the bug was fixed with Ultrix 4.4, but I was disappointed that it never was actually fixed. Source code is basically two lines:

  open("/tmp/file", O_CREAT|O_RDWR|O_BLKANDSET, 0700);
  open("/tmp/file", O_RDWR|O_BLKANDSET, 0);

.. run and then hit ctrl-c

AutoRunner, written in Pascal for the Commodore Amiga. This program automatically executes a command line when a disk is inserted. Similar to Microsoft Windows AutoRun feature, which runs commands when a CD is inserted -- the difference being that I thought of it first! (sometime near 1988, long before Window95)

Maybe Microsoft just stole the idea, but I suppose it's possible that they "innovated" it independently.  Look for it on Fred Fish Disk 744.

TradeWars 2000 visualization program.  TradeWars 2000 was a text-based multiplayer game set in a Star Wars-like universe divided into a thousand 'sectors' each connected by 1-7 'warps' to other sectors.  The visualization program I wrote was a terminal emulator that parsed the game data as the game was played and displayed a graph of the universe along with tools to efficiently explore it (discover unvisited sectors), find optimal 'base' locations, aid in trading to aquire credits, and help play the game in several other ways.


Basic2Basic, written in Amiga Basic. This converted Amiga Basic programs into GWBASIC programs. Amiga Basic was one of the newer BASICs, where line numbers were not needed and also it had subroutines, labels, and if..then blocks (in old-school BASICs the code after then had to fit on one line). Amiga Basic if..then blocks were converted to GOSUBs to the code, plus a return. Subroutines, labels and other features of Amiga Basic were converted into forms gwbasic could understand. Line numbers were added since gw needed them.

Later I went back to figure out how I had written the program and how I should  have done it, after the all my college Buchlernen .  Basic of any kind isn't a very friendly language to do this sort of thing in and looking back at the way I had done it just blew my mind it was so cool!  I'll have to dig it up sometime and post it.

TetraWriter, written in C64 BASIC, was my first text editor (a character based one).  The program basically just remembered everything you typed in, and saved and loaded it.  Changing the text color was fun, and at the time I thought it was neat that it 'typed' the letters just as you did, changes and all.  Porting this to AmigaBASIC was an early object lesson in writing clean code, and I took it to heart -- it was simply impossible to port: loops that end earlier in the code than they began were simply not allowed.  I was really young at the time!

Since then I've written two other text editors, one storing the text in memory as whole lines and another, using a kind of buffer-gap approach.