Frogger

It's been a long time since I posted anything on this blog, and that's because I haven't done anything retro-porting related in all that time. I had started on a now-stalled project creating a new core for the MiSTer hardware, but even that was probably a year ago now.

In recent weeks I decided it was time to work on another port. To be honest, I struggled to find a candidate that I was both interested in personally, and could run on the Neo Geo - my favourite retro platform for porting. I was really looking for a horizontal title, but finally settled on Frogger thinking it would be relatively simple. After all, I had done Galaxian and it is essentially the same hardware.

I'm now a few weeks into the RE - I'd estimate about 65% done - and have actually started on the 68K implementation before finishing the RE. Initially the decision to start on the implementation was more due to impatience than anything else, but I've actually found it helps with the RE.

Not surprisingly, I was able to create the Neo Geo assets for Frogger using the same tools I built for Galaxian, almost without any changes. Ditto for the Neo Geo code itself. I'll have to keep this in mind for any future projects on the same hardware, and there were quite a lot of games on Galaxian hardware, even if some were bootlegs.

So, right now the attract screens - title, points table, high score, insert coin - have all been implemented. The static elements of the gameplay screen are drawn in attract mode, and the frog happily leaps across an otherwise empty screen as the time bar counts down. You can also coin up and start a game, though visually it appears to just hang on the start screen. A crude comparison of the Z80 and 68K assembler listings would suggest the transcode is about 21% done.

A few screenshots of  Neo Geo Frogger in action.

The frog hops around in the attract mode gameplay

The next step is adding gameplay elements. This will be a process of RE and transcoding in parallel.