intric8 wrote: ↑
Fri May 22, 2020 10:02 am
Have you seen the Unamiga 1200
? It started shipping this month.
Not dissing the incredible amount of work in recreating the Amiga 1200 motherboard, but not all of us are either skilled enough or willing to solder on a few thousand pins of surface mount chips. The Re-Amiga (and all bare PCB recreations) really only suit a very small percentage of users.
Edit: Unless you're referring to Edu Arana's excellent Unamiga 500 adapter. Sadly it's sold out and not A1200-case compatible. It shouldn't be too hard thought to wiggle some things around for it to be so.
To my knowledge there are only two sets of cores that are based on actual per-chip reverse engineering. The cores that Jens has and sells as part of his Indivision ECS and AGA products (and the defunct Clone-A project). This is only Denise/Lisa and it's not known if they ever completely reverse engineered Agnus and Paula.
The second is FrenchShark's efforts for the MCC-216 project. I've uploaded the source he released onto my github. You can tell they're MUCH closer than MiniMig because they're a fraction of the size. The original Amiga engineers were very miserly with gates and the logic on these chips is really mind numbing. But even FrenchShark's designs were missing a FEW features and had to break perfect compatibility because the original chips are a) NMOS based and b) used a lot of multi-phased clocks -- neither of which translate well to FPGA.
MiniMig and the Vampire are both reimplementations based on "best effort" forward-engineering from the schematics, hardware reference manuals and testing with software. In some cases, they've leveraged work from Toni for verification. In both cases, they lack a LOT of critical features of the chipset. At no point could either of these serve as drop-in replacements to the real chips.
Of the top of my head, the big issues on MiniMig are the lack of productivity modes and superhires. The Vampire also has this limitation along with broken interlacing that can LITERALLY DESTROY YOUR LCD.
I believe Jeri has the complete schematics of OCS Denise and I have some incomplete schematics from Agnus/Alice. Not sure if there are copies of Paula around, but out of the three chips, Paula was the best documented and it's relatively well understood.
MikeJ also has the complete NETLIST from the decapsulated AGA chipset. However, it's still going to be a ton of work to generate gates and logic from that.