New type of accelerator design?

[wawrzon]

@bloodline: im really sorry that i cant give you a reasonable answer. the fact is when i try aros another time it as if it just rejects me (not even when it crashes, i just play a little around get bored and then forget it). on os4 happens something similar. i have it installed, but i run it today only to test one thing or another and then switch back to 3.9. for mos i dont have hardware and i dont even know when ive run winuae for the last time. i must be a hopeless cause i guess, but being a true retard i feel good with it.

[lapeno]

I personally like the idea of a new style of accelerator. Nowdays you can only buy 2nd hand accelerators and they might not work.
I don't think about a big gun like PPC or faster processors. I beleive the old Amiga systems must stay 68k based so a 68030, 68040 and 68060 based accelerator is a good idea.  
The Natami project is very good , I like it but that is not our much loved old HW. I am sure I will buy one but beside that I will always have the A1200.

One of the main drawback of the A1200 is its 14Mhz local bus. You can design a fast accelerator but that will always have to talk to the motherboard using 14Mhz clock driven protocol. That is why if you make different tests with different  accelerators the CHIP ram read and write time is nearly the same for all. An accelerator card itself is a small computer which is fast on its own board but access to outside (towards the A1200 motherboard) is slow.
This however doesn't mean that we have to give it up!

I started to think on a new design which is using FPGA for the main bus driver plus memory controller logic and have SIMM modules (or even DIMM SDRAM) as memory. CPU would be a 68030 040 or 060 but in order to make a twist on the design and create something new I would put 2 CPUs, a 68030 and a 68040/60 on it. During power on the system would startup with the fastest CPU but if you would hold down a key a menu would appear where you could choose between the onboard 020, the accelerator's 030 or 060 CPUs. Just like in WinUAE you set the CPU type. After you have chosen the system would reboot and startup with the chosen CPU.
One more important thing would be that if you would choose the motherboard's 68020 as CPU then you could have 8MB of Fast RAM from the accelerator card (even if you have a 128MB SIMM on it).

I beleive it is possible and even if this would not make money it would be a good experience to create it. I don't know whether it will ever come true but I started to investigate the hardware docs and how the Amiga bus system works. I will make some feasibility studies and develop some part of it (e.g. DRAM controller, A1200 motherboard local bus bridge). If any of you have good, unpublished or rare doc about the A1200's inside please share that with me!

Thanks

[tone007]

I don't think about a big gun like PPC or faster processors. I beleive the old Amiga systems must stay 68k based so a 68030, 68040 and 68060 based accelerator is a good idea.  

There seem to be enough of the lower-end accelerators to go around, judging by prices, at least for the A1200/2000/3000/4000s.  Do you think you'll get a newly designed one for less money than existing accelerators?

[Boudicca]

Why ? Because you can ? or a technical exercise ?

http://www.lauterbach.de/frames.html?ice68020.html doesnt it already exist ? With a bit of glue and nails ?

or even http://www.lauterbach.co.uk/frames.html?ice68040.html

[Cammy]

There seem to be enough of the lower-end accelerators to go around, judging by prices, at least for the A1200/2000/3000/4000s.  Do you think you'll get a newly designed one for less money than existing accelerators?

There are NOT enough accelerators around, what are you talking about? Every time one pops up on eBay you get a bidding war and they sell for as much as new hardware or more. One accelerator with more than one person trying to buy it means there's not enough supply, but plenty of demand.

If you make a new A1200 accelerator or RAM card, people WILL buy it. You would sell the whole run in no time. Just look how quickly GVP-m ran out of A1200 accelerators when they announced a new batch earlier in the year (or late last year, whenever it was).

[tone007]

I guess it depends what kind of accelerator we're talking about. The '030 cards are fairly common, and sell for ~$200 generally.  AmigaKit has had some listed at $229 for months now, either they've got a ton of them or people are holding out for something better, or are finding what they need on the used market.  I doubt a newly designed and manufactured card could compete with those prices.

The '040s and (especially) '060s are another story as there seem to be a lot less of them kicking around.

As for simple RAM cards, I've never paid much attention to those when it comes to the 1200, but from what I've seen they do sell for a bit more than I'd pay for one.

[sim085]

What about this project:
http://eab.abime.net/showthread.php?t=36596

Looks fairly realistic to me. It is for the A600 and maybe the A500. But its a start.

[Cammy]

An accelerator like the one proposed here would be far faster than an 060, and that'd really give classic Amigas a well needed performance boost. 030s aren't that hard to come by, that's true, but the 060s are rare and generally go for more than most of us can afford to pay.

The 020 for the A600 and A500 is going to be awesome though, I'd gladly get a few of these once the project is finished.

I think a simple 8MB RAM card (with automatic switching to 5.5MB when the PCMCIA slot is in use) with a Real-Time Clock on it would be a nice new expansion too, and perfect for WHDLoad and basic internet stuff (even one page at a time browsing). Just like a new internal 8MB RAM/RTC/Clockport expansion for the CD32 would be awesome, especially if it had an ethernet port on it.

[DIBBEERZ]

hmm have allways thought of what happens to the on board 020 when an accelerator
is plugged in ? i guess its switched out the curcuit turned off ? seames a waste what with miuti cores cpu computers would it be possible to re switch it back on and use it some were like on a interupt and allocate it some ram ?
 
doh im not thinkin interupt a 030 to exe a 020 = slower ! maybe its a stupid post and you carnt have both cpu on the bus together they would totally crash

[Zac67]

Depending on accelerator design it could theoretically be possible to keep both CPUs on the bus, but don't expect anything Amigaish to support a 2nd CPU for SMP. You'd need to run a separate OS on the secondary CPU (similar to a WarpOS setup) and some elaborate method to make them communicate.

[bloodline]

Depending on accelerator design it could theoretically be possible to keep both CPUs on the bus, but don't expect anything Amigaish to support a 2nd CPU for SMP. You'd need to run a separate OS on the secondary CPU (similar to a WarpOS setup) and some elaborate method to make them communicate.

PowerUp

[tone007]

Depending on accelerator design it could theoretically be possible to keep both CPUs on the bus, but don't expect anything Amigaish to support a 2nd CPU for SMP.

Wouldn't be SMP either way, unless your second processor was the same as the one onboard (or acting like it.) Asymmetric multiprocessing, anyone?

[recidivist]

Many would be happy just to  get their hands on a new production of  PPC accelerators.$600 and up for old 200 Mhz  600 series PPC cards shows tyhere is demand.

[NovaCoder]

If you're talking about using the classic chipset (eg a 1200), the faster the accelerator the less sense it makes (as detailed above).  

It makes more sense for a 3000/4000 though because they don't actually use the chipset (in which case are they even really Amiga's in the first place?).

[tone007]

It makes more sense for a 3000/4000 though which don't actually use the chipset (in which case are they even really Amiga's in the first place?).

This nonsense requires clarification.  No Amiga chipset in the 3000/4000?  Where are you getting that?

[tone007]

If you're talking about using the classic chipset (eg a 1200), the faster the accelerator the less sense it makes (as detailed above).  

It makes more sense for a 3000/4000 though because they don't actually use the chipset (in which case are they even really Amiga's in the first place?).

You seem to be a bit confused.  The 1200 and 4000 share a chipset, the 3000 is closer to the "original" chipset but they're all the Amiga chipset, just different revisions.