I may have lost track of it also 😕. Been out of action for a while, but as far as I remember Juno First was mostly missing some sound effects and other minor stuff? I'm on holiday right now - DM me and that'll remind me to find the last release and send you it when I get back.

All good cheers, same to you 😄

Might have put my head in the sand for a bit on that one 😆. I have viable samples working for all but one of the sound effects and honestly replicating an sn76477 properly is out of my league for now!

With some pointers from Norbert I added the missing CRT initialisation code and re-assembled the Vantris ROM, and it now works without the hacked hardware, so should be good on a real board as well 👍 Bit of a fun side-quest complete, should really get back to finishing the core again now!

I sent the original writer of the Vantris homebrew an email to let him know that it has resurfaced 25 years later and is finally getting tested on something approaching real hardware! Might give him a nostalgia hit if nothing else 😄

Turns out it worked just fine, but I did have to initialise the video system values to the ones Vanguard usually sets at runtime or there was no display output! Makes me think this homebrew probably wouldn't run on a real board 🤔

Cool, I had no idea! I'll try out the ROM in the sim and see if it runs 👍

Next on the sound front was the music - probably the most fun part of building this core. It's a surprisingly simple wave generator built using a bunch of timers, controlled by frequencies read from a ROM. Didn't quite get the pitch/speed right for this test but it's certainly ... recognisable 😂

After working out some of the visual bugs (definitely not all) I started work on the sound, which is usually my absolute nemesis 😅 The majority of the sounds are reproduced with samples, as is the case in MAME - handy because I could just copy my sample player code from Carnival! (volume warning?)

After a bunch of banging my head against tilemaps (problematic because of a sequence of static RAM lookups that happen far faster on the original hardware than I could manage with BRAM on MiSTer) things were definitely looking better...apart from playing as a trio of hotdogs 😂

This was the first video output from the simulation where something recognizable was happening. Pretty grim!

That looks neat, I'll check it out, cheers!