Articles by Retro Ports

Now up to the demo proper. The initial landscape is drawn (hard-coded routine, not part of the landscape data), the stage indicator on the head-up display is rendered, and things are about to start moving! As I suspected, the demo will comprise much of the remainder of the code, which …

 Transcoding is progressing nicely. The three attract mode screens (challenge, high scores and score table) are now complete, and the game cycles through to start the demo. The sequence and timing of events and colours and graphics all match what’s happening in MAME (graphics corruption aside). I’ve been …

 Not a lot of time so minimal progress, but something to show for it. So far the code has been straightforward to transcode. I think that’ll be the case for quite a while yet, as I work through the attract mode scripts and underlying functionality. I’m not quite …

 Very quick update as it’s late… implementing the script processing and now it clears the rectangles and prints “HIGH SCORE” in attract mode. There’s a bit of jumping around in the code, but on closer inspection it can be unravelled into a single function… at least that’s how …

I got a few minutes to start on the transcode today. I did a very, very preliminary scan of the code to get an idea of the data and code structures and its suitability to be converted to C a few days ago; now I’m simply working through the execution …

I’ve now got the Scramble code reading a memory dump from MAME and rendering the tiles and sprites to faithfully recreate the display, with the correct colours. The tiles and sprites are blitted from bitmap sheets in memory, so a single call to Allegro is all that is required. It’s …

Years ago I wrote some C/Allegro code to rip the Galaxian graphics for my FPGA implementation. It displayed the graphics so I knew the format was correct, and output some VHDL source code for the palette logic and graphics ROM contents (pre-rotated for a horizontal display). Today I took that …

I know I should be finishing off projects but I just can’t get into them right now. I need something new to pique my interest before I return to that stuff. So for now, I’ve decided to look at Scott Tunstell’s Scramble source code and see if I can transcode …