I have a confession to make. I’ve never actually played a Gameboy, never even seen one up close. When I was a tadpole we had handhelds, but they were a little different. One of the most popular on my school bus was this: Electronic Quarterback. This is fairly accurate other than running a little slow, which makes it much easier than the real thing. If you want to be really accurate you’ll need to get a red marker and scribble all over your screen. We had color screens, but that color was red.
The short instructions are you select pass or run. On a run play just try to run forward using your 2 blockers to help you. On a pass you are moving your lower dot downfield try to line him up with your QB and press A to pass. When the play’s over you press B to see the down & distance, and press it a second time to see the score and time. You can read the instructions here: (https://archive.org/details/hh_cqback) We’re short a button so if you hold B and press A it switches the play call from run to pass. This is indicated in the upper right of the screen.
This uses a TMS1100 which is basically a hacked up calculator chip from the early 70’s. I thought a 4 bit CPU would be easier, but no. What sane person would have thought of using a random number generator for a program counter? Also it has 1 byte opcodes, also not as cool as it seems. It means every branch is basically an indirect jump so I couldn’t easily use static recompilation like I’ve been doing. Every memory read/write takes multiple opcodes to do, which makes it hard to optimize, or even understand the disassembly. That’s one reason why it’s running a little slow. Not sure how to speed it up, there’s no frames to skip. In retrospect maybe I should have put the extra effort in to do a static recompile.
One thing that was really helpful and kind of interesting was the patent app. http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F4249735.
EQBack.ino.leonardo.hex (33.7 KB)