FPGA Replay Board

[psxphill]

There is no "emulation"..

Please don't start this discussion again, emulation doesn't mean what you want it to.

[psxphill]

Indeed not, any FPGA implementation is a re-implementation of the hardware, not an emulation of the hardware. Emulation implies a software shim between the native hardware and the emulated hardware.

That is the problem. That is what you infer, but that is not what it implies at all.
 
While I hate to quote Wikipedia because you'll just l0lz
 
http://en.wikipedia.org/wiki/Emulator
 
"A hardware emulator is an emulator which takes the form of a hardware device. Examples include the DOS-compatible card installed in some old-world Macintoshes like Centris 610 or Performa 630 that allowed them to run PC programs and FPGA-based hardware emulators."
 
If anything an fpga could be more of an emulation than a software emulator, as generally software emulators only simulate the individual chips & using an fpga you can get closer to using the same techniques as the original chips. It's only recently that a bunch of chip software simulations that have been strung together has actually been referred to as emulation, previously it was only hardware based solutions that qualified.
 
If you're going to argue about what an fpga behaving like an amiga is or isn't, then please use the correct terminology.

[psxphill]

It's not an "emulator", as the commonly understood meaning is "software [-implemented] emulator". We then get people who think Minimig is just UAE running in an FPGA, when that is most certainly not the case.

I get why you don't want to call it an emulator. It goes back to the "I hate winuae, winuae is an emulator, therefore I hate emulators, I love fpga, therefore fpga isn't an emulator" logical fallacy.
 
Pandering to the uneducated is stupid.
 

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.

You'll change your mind when we have a CPU with a million cores and someone writes an emulator that dedicates each core to one gate. For now you're too hung up on implementation details, rather than concepts.

[psxphill]

It may not be an emulator. Who the hell cares !

Apparently freqmax & Hattig do. I'm not sure whether they are trolling or not. But Jim Drew said he wanted to write some emulations for it and they both jumped on him.

[psxphill]

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.

That argument reminds me of the "there is no such thing as fish" argument.
 
http://swimmingunderwaterblog.blogspot.co.uk/2011/09/there-is-no-such-thing-as-fish.html

[psxphill]

Why are you so persistent to ruin it for us. We want implementation not emulation. I will not pay money for emulator in a hardware, please don't ruin FPGA for me! I want a reimplemented upgraded new technology to the old technology of the Amiga classic. FPGA Replay is doing that for me so don't enforce "emulation" into this. Let me enjoy it. Please.

I'll assume that this is sarcasm :-)
 
A rose by any other name would smell as sweet.

[psxphill]

I don't cringe at the word "emulation", I just prefer to have different words for things based on different underlying technology. It has nothing to do with which one is "better".

Except emulation doesn't define the underlying technology.
 
It's like saying you can't have a car with an electric motor, because all cars have internal combustion engines.

[psxphill]

Please discuss the non re-implementation issues in the "FPGA for dummies" thread.

Yes, the next time we talk about emulation and you want to tell us that using an fpga isn't emulation... please go in the FPGA for dummies thread to discuss it.

[psxphill]

Examples: Minimig on Replay using an Xilinx Spartan3E FPGA, Boxer.

this is quite a cool one too.
 
http://opencores.org/project,zx_ula

[psxphill]

Great Giana Sisters was allowed under the law. Parodies are a protected right and have been upheld in countless court cases. But that didn't stop Nintendo from crushing the Giana Sisters .

I don't believe Nintendo ever sued, they said they would if the game wasn't withdrawn. So the game was withdrawn. Parodies are only protected in the US, so Nintendo would probably have won.
 

Plus you have to word things carefully. And anyway he can't say anything about NES emu on kickstarter. Its an instant lawsuit from Nintendo. Even if the core exists and works perfectly he still can't say anything about it on kickstarter. Do u want him to get assasinated? :crazy:

That would be an interesting one.
 
1. They actively stop DS flash carts.
 
2. A lot of the NES games are available on Wii Virtual Console, so they could argue that it destroys revenue.
 
3. In the UK you aren't covered by any right to copy your NES cart onto different media, you technically require permission from the music company to rip your cd to play on your iPod. Some European countries do allow it, but not all. An individual is unlikely to get sued in the UK, because the court would see it as a waste of time. However going after someone who is profiting from copyright violations is possible. It wouldn't stop the kickstarter, but staying off the radar is probably a good idea to prevent import restrictions in various countries.
 
The landmark cases in emulation being legal are Sony VS Connectix, however Virtual Game Station was deemed legal because
 
1. it was in the US where you have fair use.
2. it had a legitimate use as the PC could play the game from an original CD.
 
It would be annoying if I couldn't buy one, in the same way I'm sure some people in the US are annoyed they can't buy from here http://www.originalstormtrooper.com/ For various reasons the guy who made the original storm trooper costumes can make reproductions and sell them in the UK, but he can't sell them in the US.

[psxphill]

Apple actively wanted to murder off the 680x0 line, which they did.

Apple just wanted to be competitive with PC's.
 
Motorola had already decided that the PowerPC was their future for computers. The 680x0 ended up as their embedded offering, which mutated into coldfire.
 
I don't know why Motorola made coldfire incompatible with 68000, that is the only decision I can't understand.

[psxphill]

Coldfire is supposedly faster or could be clocked faster because some overhead was removed so that a more "raw" core remained. Corporate decisions are not known throughout the history for their wisdom

I can see why some things might be removed, but they'd kept their ISA pretty compatible for years and then just started reusing opcodes. Using previously unused opcodes for new instructions and causing removed opcodes to trigger an exception would have been more logical.

[psxphill]

I guess you worried them enough that they dropped the MacOS+68k and headed to greener pastures with OSX+PPC . Apple did change their minds about Mac clones so maybe that is when they decided to sabotage the ROM to not work on the 68060 .

Apple committed to PowerPC in 1991. They had already started shipping PowerPC machines by the time the Quadra 630 came out, they didn't just wake up one day and decide to switch.
 
Because Apple never shipped a 68060 based Apple and nobody produced an accelerator, it would be tricky for them to make sure it was compatible when making changes. Even if they suspected it wasn't compatible, then there would be no business case for making a best guess at trying to make it compatible. The programmers would never know if they were successful.
 
Mac clones were stopped when Steve Jobs came back. They did by releasing OS 8 as they'd only licensed OS 7 to the clone manufacturers. They did have to stop the clones as Apple's business model is based around overcharging for hardware, if others are cloning it and selling it cheaper then Apple would run out of money quick.

[psxphill]

I don't agree. The ColdFire was incompatible from the beginning. The later changes to the ISA used unused 68k encoding space as I recall.

I know coldfire was incompatible from the beginning, but for years Motorola had done their best to keep the 68000 ISA compatible across all their processors. Even the MOVE SR change can be emulated using a trap.
 
Lots of things were removed from coldfire, but if they'd just made those trap then apart from a speed drop there wouldn't be a problem. Some instructions on coldfire did something similar to 68000, so they used the same opcode. They should have trapped the original opcode and implemented it as a new instruction, made the implementation the same or implemented a mode where those instructions can be trapped or not.
 
It's annoying they didn't make it compatible, although whether it would have made them more money is another matter. So as a business decision it probably paid off, but they'll never know how many coldfires they could have sold to us now.

[psxphill]

I believe it was the way the auto increment works on the MOVEM instruction. Something like MOVEM.L SP,(SP)+ will behave differently on 68020 than 68000.

I'm not sure why anyone would do that.
 
Intel made the same change when pushing the stack pointer on the stack somewhere between the 8086 & 80386.

[psxphill]

That's why programs like Oxypatcher and Cyberpatcher replace instructions before they are trapped.

I'm pretty sure they replace the instructions after they are trapped the first time, not before. Hitting one trapped instruction is not a big deal, it's when you hit one every time through a loop.