Looks like my MAME adventure has changed course slightly for the time being. After learning so much about the PE+ hardware and emulating it, I decided to try my hand at creating a new romset for this platform from scratch!
The results so far are the many pictures posted here. I decided to create a game that is not currently found on this platform, and chose to go with a 3-card poker game.
The rules of the game are fairly straight-forward. You and the dealer are dealt 3 cards each and you must obtain a higher hand than the dealer. It is classic stud poker, where you don't discard and draw.
Besides the normal "ante" wager. You can place a bonus wager on the final value of your hand dealt. This "Pair Plus" wager pays even if you end up losing the hand. The bonus wager only pays if your hand is a pair or better. A paytable determines the payout for each of the bonus hands.
Once you receive your hand you can decide to either play or fold. If you play, you must place a second wager that matches your original ante. If you fold, you lose your ante wager, but can still receive your bonus payoff if you have a pair or better.
If you decide to play, the dealers cards are revealed and you are paid even money for your ante wager if you have a higher hand than the dealer. If the dealer hand qualifies (Queen high or better), your play wager also pays even money, otherwise its a push. If a tie occurs, you push both bets.
I'm developing the application using SDCC and compiling for the i8052 platform. Once compiled I convert the .HEX file to a .BIN file and test it under MAME. So far I have the video, inputs and sound mostly working. Its interesting to code from the other side of the platform. Things as simple as random number generators (which is done), etc. can be a pain to figure out, but once I am done, I will have a solid SDK for building other games.
I have been trying to create a game in the same style as IGT and therefore I have been adding support for the multiple operator screens that are used to setup the machine.
I will eventually burn the game onto a chip and test it in my real machine. But I want to make sure I have most of the bugs worked out first in MAME. Burning chips and disassembling the machine to pop in the chip takes too much time, but will need to be done sometime in the future to make sure I didn't miss something in the code (like the watchdog timer which the MAME driver ignores).
There is still plenty of code required to finish the game, but I am learning a lot about this machine as I go. And I currently have a lot of useful code for my PE+ SDK.