| It is indeed an amazing project, especially its open source nature. It provides some impressive power savings and latency reductions that are very hard to match with general purpose CPUs. But in most cases, it is emulation, as the lead developer will attest. https://github.com/MiSTer-devel/Main_MiSTer/wiki/Why-FPGA "From my point of view, if the FPGA code is based on the circuitry of real hardware (along with the usual tweaks for FPGA compatibility), then it should be called replication. Anything else is emulation, since it uses different kinds of approximation to meet the same objectives. Currently, it's hard to find a core that can truly be called a replica – most cores are based on more-or-less functional recreations rather than true circuit recreation. The most widely used CPU cores – the Z80 (T80) and MC68000 (TG68K) – are pure functional emulations, not replications. So it's okay to call FPGA cores emulators, unless they are proven to be replicas." But there's nothing wrong with emulation for preservation, until we get to a point where we can wide-scale clone these older chips down to the transistor level through analysis of delayered decap scans. And even then, emulation will be useful for artificial enhancements as well as for understanding how all those transistors actually worked at a higher level. It's also not a total solution: by taking many more transistors to programmatically simulate just one, it limits the maximum scale and frequency of what it can support. N64/PS1/Saturn has not yet been fully supported and is still theoretical, but likely, to be possible. Going beyond that is not possible at this time. Software emulation and FPGA devices should be seen as complementary approaches, rather than competitive. The developers of each often work together, and new knowledge is mutually beneficial. |
And yeah I hope we can easily order small batches of ICs (at big pitch of course) in a few years, in a similar way to how creating PCBs has become so simple now.
I mean I remember how much of a PITA it was in the 80s. Drawing on overhead sheets. All the acids and other chemicals. Drilling. And now we get super-accurate 10x10cm boards dual-layer, drilled, soldermasked and silkscreened for a buck a pop with a minimum of 10. Wow. I really hope this trend continues down to the scale of ICs (or that FPGAs simply get better/easier).
By the way, emulating a CPU is pretty easy and very accurate anyway. The big problem with accurate emulation is with some of the peripheral ICs which used hard to emulate stuff like analog sound generators.