Interval Smalltalk redux (was "SqueakOS")

Tommy Thorn thorn at meko.dk
Fri Oct 4 01:47:09 UTC 2002


Tim Rowledge wrote:

>>Not that I'm suggesting it, but FPGAs have progressed significantly in 
>>recent years. Yesterdays ASICs might be reimplementable with todays 
>>FPGAs (at a considerbly lower NRE cost).
>>    
>>
>If you were thinking of some magical hardware interpreter, forget it.
>

I'm not thinking of anything, just replying to your comments about 
custom hardware which used expensive ASICs.

You said that the native code compiler wouldn't be useful for most 
people and I was asking if it required special hardware support, or if 
the reason it wasn't useful was simply that most people don't have ARMs.

>Completely pointless unless you're doing it for fun or longterm
>research. Much better to put the effort into a good translation system
>to make good use of plain ol'vendor parts that will be twice as fast and
>half the price by the time you have it done. Don't fight Moore's Law.
>

I never said anything like that. I was refering to replacing your ASICs.

However, now that you brought it up, making a hardware (FPGA) 
implementation of Smalltalk would indeed be fun (it looks like Jercel is 
doing that) and it *might* make sense in some settings. Why do you think 
Xilinx and Altera spend millions to develop their softcores (MicroBlaze™ 
and Nios respectively) when obviously their performance can't reach that 
of a substantially cheaper of-the-shelf part? Softcores make sense for 
example for an embedded device where board space is at a premium and 
there already is a substantiel need for custom logic.

Of course for a custom general purpose system there really is no way to 
beat the performance of a $100 x86 chip.

>>Again, what special hardware support is needed? Object memory like on 
>>the Newton?
>>    
>>
>Bandwidth. Big onchip cache (128Mb would be nice :-) More bandwidth.
>Very fast interrupt handling (ARM does this part well).
>  
>

What special hardware support did the _Interval_Smalltalk_ require was 
what I meant. The StrongARM doesn't exactly have bandwidth nor big 
on-chip caches and the MediaPad's custom (external) ASIC clearly didn't 
implement a big cache.

For utmost bandwidth buy a P4 and fit it with 533 Mhz Rambus memory, but 
then we're obviously out of the embedded space. StrongARM is probably a 
bad choice anyway if you're seriously concerned about bandwidth.

/Tommy





More information about the Squeak-dev mailing list