FPGA Replay Board

[Hattig]

My only issue is that people, when they see "emulator" assume it's something like UAE and therefore not a real Amiga, and that it would have all the issues that software emulators have.

So call it a hardware level emulator, or hardware re-implementation, or FPGA implementation. But not 'emulator' in isolation.

Ask any Minimig owner if they feel they are running a real Amiga - they would say yes. There's no translation of CPU opcodes going on, there's no software implementation of the chipset. That's because it is running the CPU opcodes directly on the hardware, it's hitting the chipset registers directly in the hardware, and so on.  It's not the original hardware, no. But we don't say that AGA emulates OCS do we?

Next up will be someone saying it's running on software because the FPGA is programmed using a netlist compiled from VHDL, which looks like software to them.

[Hattig]

Whatever. I don't hate emulators, I just see that they're massively different if you consider a software implemented emulator, and a hardware implemented emulator.  We had the arguments a long time ago because of LOTS of people thinking the Minimig was UAE running on an ARM or something, and then it was recognised that using the term "emulator" on its own was not useful.

I don't want to argue about this terminology to be honest, but a hardware implementation in my mind is very different from a software emulation. And in terms of potential user confusion, it's best to keep away from the "emulator" word. "Re-implementation" is a really good term IMO, it says exactly what it is.

[Hattig]

Great news! Can't wait to get one.

[Hattig]

The old core does not have cache/pre-fetch running as is not using the dedicated memory channel for RTG. It will be slow ....

I'm looking forward to reading about all the new features in the new core, once it is available. Dedicated memory channel for RTG, for example.

[Hattig]

I don't have any plans to implement a flicker-fixer. Productivity and DoublePAL/NTSC modes are much faster on Replay than on any AGA Amiga (over 8 times) so it's not a problem. Besides you have a bunch of nice RTG screen modes so why not use them?

What about when you want to fire up a game and it runs in non double PAL and you're wired up to a monitor that can't take 15kHz?

Nevertheless I'm sure someone will come up with a solution. WHDLoad+Mode Promotion?

[Hattig]

€800 is a lot for a case, power supply, some memory cards, etc!

Get a mini-Itx case with PSU or without PSU (but then you need a picoPSU + 12V AC/DC convertor (aka external brick)).

Personally I'm thinking of mounting the board between two slabs of perspex, although the pico-PSU cabling might look a bit messy. Maybe smoked perspex rather than clear.

[Hattig]

Does that even make sense?

What part of a VCS2600 was even remotely 68k based!?

I think he just wants verification that other cores will not be operationally affected by the presence of the '060 board.

I don't see how they would - the core would not be configured to interface with it, so there would be no problem. However if that other core made use of its own daughterboard there could be trouble, unless the daughterboard identifies itself to the FPGA and the core can then ignore non-matching daughterboards.

[Hattig]

Sounds good. Hope that we start seeing some videos on YouTube soon of the new cores running on the finished hardware!

[Hattig]

Would usb hid gamepads be possible to add? While 9 pin joystick ports are fine for amiga use, it's a bit limiting for other platforms. I actually can't stand old joysticks now though. ps3 controller ftw.

I expect it will be easier to add support for the USB gamepad specification in the funky programmable 16-bit-USB-stack-on-a-chip than USB networking - it's probably very similar to the keyboard / mouse specification - a collection of button presses and analogue (signed 8-bit?) signals for the joysticks.

[Hattig]

Definitely looking forward to paying and receiving this, and building a nice shiny new Amiga / Atari / C64 / CPC / Arcade machine :p

[Hattig]

Had a strange thought... How does Replay cope with Widescreen monitors? Does it keep 4:3 aspect and use bars down side or stretch screen?

Good question - there's not much you can do about classic software that assumes a 4:3 display, especially all those PAL titles that really made good use of the extra vertical resolution that PAL gave.

Maybe the non-overscanned 320x200 NTSC stuff won't look odd - that's 16:10.

[Hattig]

Can one say FPGA Replay is not a WinUAE in a hardware and that everything in it is actually custom chipset?

It's far closer to custom chipset than software emulation, if that's what you are asking. The FPGA simulates the hardware of the classic chipset directly (no software running on a generic CPU, but rather the FPGA re-implements the Amiga chipset), however the simulation is not the original hardware exactly (due to no-one having these details, and the gate level deconstruction of the original hardware is not complete yet) so there are going to be a few incompatibilities.

There are arguments about the meaning of emulation, simulation, etc, let's not go there again.

[Hattig]

Sounds good Jim. Any news on the performance of the CPU soft-core? And on the performance of AGA modes?