RL5203 Update September 2024

Entry posted by Cafeman in Homebrew September 20

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I have returned to my homebrew project 5200 Detective Powers. Product number RL5203. My small 5200 'catalog' is:

RL5201 Koffi: Yellow Kopter 2002

RL5202 Adventure II 2007 (and RL5202-A Adventure II XE for A8)

RL5203 Detective Powers 202x (I hope x=5)

I've had this project in my head since 2009, and over the years I've created designs, and worked with LS_DRACON to get the graphics, but this is the first that it has been a working runnable ROM - this is Detective Powers version 0.1. The plan is to build a basic demo for 32K 5200 with optimized / modular / clean code. I want to see how much memory a simplified 1-case version takes and basically get a working engine. Currently I'm only using about 9K of the ROM (Sprite Drawing, Sprite Movement, and Screen-changing logic exist in the ROM but aren't getting called yet). Then I want to convert that 32K contiguous code base into both 5200 and A8 64K bank-switched code bases. A8 needs 16K banks, but I'll likely use two 32K banks for 5200.

Some released demo version goals are:

DP version 0.1 - Title Screen works, START button brings player to City map with at least 1 screen and all the mixed graphics modes functioning. (Ready now)

DP version 0.2 - Start a Case and be able to control Holmes, change screens, other gameplay mechanisms work.

DP version 0.3 - more robust gameplay and some added sounds/music.

...

DP version 1.0 - finished game!

The lead development is for 5200, because I like 5200 and the Supersystem needs support FOREVER. That being the case, I'm using the 5200's controllers fully in the game. There are 2 action buttons, the numeric keypad, and easy access to Start / Pause / Reset. I'll have to keep in mind for the A8 version there is only 1 action button (Same problem I ran into with Adventure II 5200 vs XE version). I really should make a keyboard--free solution for XEGS consoles without the keyboard attachment, but this is not a priority to me. I won't implement true analog joystick control though, there is no need for it in this game.

The 5200 Keypad is currently used on the Title Screen for some simple Code Cracking. Currently I have 4 Case Clue lines. Some letters of the Case Clues are replaced with Dancing Men icons. You figure out the simple riddle verbiage, then figure out what 4-digit number it is hinting at, then enter that code to solve a Case Clue and unlock the actual Case. Eventually there will be a selection arrow to pick a case and START that case, but for now, the game only reveals the Case Name.

Currently on the Title Screen, randomly chosen Holmes quotes appear. I like to spark an interest / whet the appetite for reading Conan Doyle's Sherlock Holmes stories and to have various connections (a passage or quote, images) to the OG stories. The Holmes quotes will eventually migrate to the in-game portion.