Temporal Anomalies

While it has been seven days since I started this DevLog, this is only the third day I’ve had time to work on the project to which it directly pertains.  And in thinking about that, I decided the counter in the graphic, and number of days elapsed, will be incremented for the number of days of actual work on the project, rather than just the elapsed time since I started.

Progress (or Lack-Thereof)

I had expected to have a working title/travel screen by today.  However, two days of unexpected travel, coupled with accidentally nearly removing the top of my index finger (and the day lost dealing with that), put paid to this notion.  Typing is currently very slow, and not especially comfortable as a result.

But the main/travel screen is the next thing I start in earnest here today, just as soon I post this.

Fiddling with This Project

I did define the architecture for the overall program, code and data.  In simple terms, the “Travel Screen” will be the central core of the game, main-loop controller and dispatcher.  The various mini games will be modular.  Graphics (in particular, the “landmarks”) will be externalized and loaded on demand.  Perhaps I’ll translate my tablet-based scribbles into a formal diagram.

Prep & Practice - Project-adjacent/Atari Development Related Activities

I created simple, dedicated, programs to verify a) I’ve retained/or refreshed my ability to use the various techniques and capabilities of the Atari 8-bit platform as-needed for this, and several other projects.  This involved copious references (to the point it probably amounts to re-reading them) to De Re Atari, Compute’s 1st and 2nd Books of Atari Graphics, and some delving into Atari Graphics and Arcade Game Design.  Along with going through the entire 6502 instruction set (various references).

These verifications/experiments covered:

• Display Lists
• Display List Interrupts (single, multiple, indexed and chained, as well as long-running DLIs)
• Player/Missile Graphics (simple, horizontally multiplexed, and vertically delineated)
• Custom Character Sets,
• Smooth Scrolling (w/ and w/o multiple levels of parallax)
• Display Kernels
• Direct Disk I/O.

I also did some experimentation with both dynamically and pre-shifted character graphics for soft-sprites.  Right now, that’s for a couple of cases on this project where I don’t think I can get the pixel and color resolution on I need with Player/Missile Graphics without making other things more complicated.

In some cases, the programs I created to verify my understanding, and play with some of the advanced use-cases/explore critical timing, and/or clarify my recollection/documentation combined multiple techniques.

Notably, for me … at the end of this, I was very surprised as to how much I had retained from when last did this … back in 1982/1983.

I also created a series of macros for MADS for descriptively building Display Lists, setting up and managing Display List Interrupts, some general DLI/VBI related utility functions.  I’m familiar with the excellent work that @kenjennings has done with his “Atari-Mads-Includes”; I may elect to use that instead (it's really nicely put together, and quite expansive) – but for what I’ve done this week, I wanted something a) that worked a little differently (differences in coding style/philosophy perhaps) and b) to do myself for familiarization purposes (both with the underlying Atari subsystems and the MADS assembler).

What’s Next?

Building the basic Travel Screen (which will be the foundation of the Title Screen, also, as well as, eventually, the core of the game model), and post the code and binary.  Possible I’ll have that done by EoD tomorrow (5/19/24) … but Monday is more likely ... at least as long as I don't undertake further attempts to injure/maim myself.

Regardless, it won’t be final; just illustrative.  In particular, the graphics are likely to be quite rudimentary – large on account of my complete and utter lack of artistic ability.  Though I will likely have the specs for the various graphics I need to create or commission (etc.).