Faster/wider CPU...

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Brane2
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Re: Faster/wider CPU...

Postby Brane2 » Tue Jan 31, 2012 7:16 pm

I, ve just took a peek at MC68SEC's Usem manual addendum and it seems like optimal solution.

It is fully static, which means that you can vary its clock in however you want inside declarated limits- you can even stop it completely.

It is meant to operate at 3,3V, but is fully capable working at 5V and addendum says that it is fully compatible with classic 68000.

I like it better than EC version. Farnell in Slovenia offers it for €12.

Nice static RAM 512kx8 - 10 ns in TSSOP44 is €6.12 - this seems optimal for fast "slow RAM"...

Nice cool, cheap CPLD is for example Xilinx XC95144XL €144 macrocells and 113I/O pins for €6+

Edit: If you don't mind FBGA housing, Lattice hase even (much) better model from MachX0 series - 159 I/O, 640 macrocells, 500 MHz fmax for €10+...


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tofro
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Re: Faster/wider CPU...

Postby tofro » Wed Feb 01, 2012 12:07 pm

and, probably the most important:

It can be made to live with an 8 bit data bus.


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Brane2
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Re: Faster/wider CPU...

Postby Brane2 » Wed Feb 01, 2012 4:37 pm

Why is that important ?

I mean, why would you use 8-bit bus on expansion card ?

AFAIK it's not like you could swutch it dynamicaly and use it only for some address regions ( e.g for ULA2)- it has to be selected before first instruction is executed...


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Re: Faster/wider CPU...

Postby tofro » Wed Feb 01, 2012 6:23 pm

Brane2 wrote:Why is that important ?


Ehhm, maybe because the original poster asked for it?


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Brane2
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Re: Faster/wider CPU...

Postby Brane2 » Wed Feb 01, 2012 7:47 pm

After all, this might become interesting pissing contest:

Who can make fastest 68000-based QL. With original Motorola or its successor Freescale and no 10/20/40/60 or any other numbers except 000.

It would be utterly futile, but interesting... :mrgreen:


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Re: Faster/wider CPU...

Postby Dave » Wed Feb 01, 2012 9:46 pm

Can we have a developer's area where only *registered developers* can have conversations in peace? :)


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Re: Faster/wider CPU...

Postby Brane2 » Wed Feb 01, 2012 11:59 pm

Registered, where ? As in sprinkled with holly water by uncle CLive ? :mrgreen:

It's easy, really.

Open the new theme with the name of your project and in the body of the first post set the rules.

Just say directly what you want.
No need for faggotisms of political correctness.

Allthough, if you reed calmly ym posts again, I bet you could see useful suggestion or two there.
If you don't need them, fine. But I don't feel bad for giving them, since you asked for such suggestions when you have opened the theme.

As said, if you don't like it, why don't you open another and set different "rules" there ?


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Peter
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Re: Faster/wider CPU...

Postby Peter » Thu Feb 02, 2012 1:46 am

Hi folks,

what a long thread about new hardware... maybe I should make a few comments.

I'm aware of Natami. I contacted them in the hope their FPGA core was more correct than the one I use. Their answer sounded vague and not too optimistic. Moreover, their core is not available for others. My attempts to have a look at it failed. So unless one wants pure Amiga, I see not a big chance there.

My FPGA system can execute C compiled 68k code or Atari/Amiga code for half a decade. No problem on that level. But hand-optimized QL assembler code, especially Minerva, is a much harder challenge. While it is true that I lost many years for the operating system/driver issues, I have at least rudimentary versions of Minerva and QDOS Classic by now. The problem _today_ is a CPU problem again, which is extremely difficult to debug. And lack of time.

SMSQ/E is useless as basis for new major hardware. This was done by installing a new license more than a decade ago. Ever since then, not a single QL-style mainboard etc. made it.

It is beyond me, why Rich promotes SMSQ/E as "surely the preferable way to go". Of ocurse it is not, and I'll try to explain again for this forum. I wasted years on attempting a free QL OS as a basis for new hardware, instead of dealing with the technical core challenges. It would be nice if at least a few persons understand the tragedy.

1. The socalled SMSQ/E registrar can always reject code contributions. Not much of a problem for small, low-risk contributions. Or for folks who have the right personal "connections". But who shall work on large amounts of code, on which hardware investments depend, while he has absolutely no guarantee his work will ever make it into the binary ???

2. SMSQ/E reserves the right to go closed source again. And some parts are closed. One can hope it will never happen, but pure hope is not a good basis to invest money into mainboard development. The risk seems small nowadays, simply because SMSQ/E has become unimportant, but it is still there.

3. It takes an indefinite amount of time until the "registrar" decides to include code. Shall the hardware guy risk to wait years before even small bugfixes can be passed to the user? Not be able to sell mainboards during all that time? How about the financial side? And the fact that hardware quickly becomes outdated? How about users who have bought hardware and have problems during those years of waiting for Mr. registrar?

4. SMSQ/E has been made incompatible to many open source licenses, not only the GPL. So if your code is covered by one of them, it is illegal to link with SMSQ/E. Re-invent the wheel for hardware support, just to satisfy a ridiculous license?

5. Oh yes, one could theoretically distribute changes to SMSQ/E as binary patches and every individual user would have to build his OS himself! How practical is that? What if the SMSQ/E binary is updated? Version maintainance? How will the hardware run, if the boot process already requires patches, which the user can not apply because he can not boot? How about the extra difficulty to create code in a "patchable way" instead of inserting/modifying at the place where the code belongs? Waste days for that? Weeks? Waste more time on every update of the OS? If it was practical, why did nobody ever do it?

All the best
Peter


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Re: Faster/wider CPU...

Postby Brane2 » Thu Feb 02, 2012 2:32 am

@Peter:

Great post. few questions:

1. What is the nature of your solution ? I mean, is it to be closed-source solution ( without the VHDL/Verilog sources) or open one and if so, how much ? I mean, will there be schematics& PCB available ?
How about source for whatever OS you decide to implement ?

2. What exactly is on board ( which FPGA, what kind of RAM & qty, which intterfaces and in which form is it- is it in some kind of ITX form for PC case or something else ?

3. What are roughly capabilities of your core ? HOw about the rest of the hardware ? Graphics ? Sound ? DMA channels ? Extension bus type and bandwidth ?

4. I don't understand your gripe about having the troubles with "optimized assembly".
Do you mean to say that Minerva authors did some time sensitive looping in there ?
Even if so, was it really such problem to debug it ? Minerva is "only" 48K binary... :)

EDIT: I reread your point. I understand now, but I don't get why is CPU now such a "challenge" and "extremely hard to debug"... :roll:


5. Even if problems with Minerva proved to be not worth the effort, couldn't at least QDOS successor be created ? Judging from the API book, whole QDOS is not that much more than a bunch of TRAPs...

EDIT: I type to fast, even before I actually read the response... :oops:
So, you have Minerva and QDOS working. Still, how much of an effort would be to offer next-gen QDOS as basis for further development ( so folks could create GUI etc) ?
Last edited by Brane2 on Thu Feb 02, 2012 5:56 am, edited 1 time in total.


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Re: Faster/wider CPU...

Postby Dave » Thu Feb 02, 2012 4:48 am

Hi Peter,

I really appreciate your input into this thread.

I agree with you on the SMSQ/E license situation - I think it is a very unfortunate license that was designed not to encourage development (which it hasn't) but to protect incumbent interests (which it has.)

Is it possible to contact Lau and obtain the sources or rights to Minerva? I am convinced he knows it's economically worthless now, and if he decided to extract a price for it, it could be reasonably small. Is that an option? I know most of it is freely available, but the whole thing, not quite.



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