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Re: Parallax Propeller

From Peter Jakacki <peterjakacki@gmail.com>
Subject Re: Parallax Propeller
Newsgroups comp.lang.forth, comp.arch.embedded
References <lCsIs.2517$1k5.1748@viwinnwfe01.internal.bigpond.com> <XeqdnWlVy7ZKFm_NnZ2dnUVZ8r2dnZ2d@bt.com> <LFxIs.2582$Ow3.159@viwinnwfe02.internal.bigpond.com> <50f5b79d$0$6574$9b4e6d93@newsspool3.arcor-online.net>
Message-ID <aKrJs.2633$1k5.2262@viwinnwfe01.internal.bigpond.com> (permalink)
Date 2013-01-16 06:26 +0000
Organization BigPond

Cross-posted to 2 groups.

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On Tue, 15 Jan 2013 21:10:08 +0100, Rafael Deliano wrote:

>> you will probably continue to have this misconceptions. Is that the way
>> that the Propeller comes across? I've always wondered about that.
> 
> Un unusal/non-mainstream architecture will always be initally misjudged.
> 
> But some of the misconceptions are due to Parallax:
>    if it has a smallish videogenerator then its probably
> a retro arcade game machine chip ?
>    While the spin language is usable, there
> is nothing people like less then learning new weird languages.
> (
> http://www.parallax.com/portals/0/propellerqna/Content/QnaTopics/
QnaSpin.htm
> "Spin was inspired by portions of C, Delphi, and Python,
> and a host of problem/solution scenarios ..." )
> It could have easily been an extended BASIC or FORTH.
> 
> There are issues in implementation:
>    The upper half of the 64k byte memorymap is a 32kbyte ROM
> that contains the small 4k byte spin interpreter. That ROM is rather
> underutilized with data tables.
> This spin interpreter firmware is encrypted
> http://propeller.wikispaces.com/Cracking+Open+the+Propeller+-+Original
+Page
> Which makes implementing other languages ontop of it certainly much fun.
>    Not much copy protection for the user
> as the chip boots the application from an external serial EEPROM to its
> internal SRAM.
> 
> There are issues in the basic concept:
>    The round-robin access doesn´t scale very well.
> If you go from 8 to 16 cores, the clock has to double otherwise speed is
> down. So a 100 pin chip can hardly have 64 cores.
>    One can think of COG-RAM to HUB-RAM as an analogy
> to the zero-page of an old 6502. But the speed penalty is much worse: 4
> clocks for COG versus 8...23 for HUB.
>    Identical cores are one-size-fits-all. The propeller
> may be flexible and fast concerning I/O, bit banging.
> But an I/O core that interprets bytecode is probably no match for even
> the smallest ARM in executing high level language.
> 
> MfG  JRD

Round-robin access doesn't have to scale, it is what it is and trying to 
judge it based on how it might operate as it is but with 64 cores is 
weird!! Just judge it as it is. Besides, the successor chip still has 8 
cores but allows 8 longs to be accessed in one "round-robin" cycle. The 
fixed round-robin access provides a guaranteed access time for cogs which 
might otherwise have been upset by some resource crazed object. 

The smallest or largest ARM has to handle more than one task plus 
interrupts etc so it never ever achieves it's full speed. If everything 
fits in 512 longs of a very code efficient cog then it is very fast but 
even more so because it's not bogged down like an ARM. I can't write any 
ARM code that doesn't have to do everything including washing the dishes 
but the ARM does have a large code space without a doubt. The high level 
code rarely needs to run fast though, it's all the low-level stuff that 
needs priority which on an ARM requires some complex interrupt processing 
to hopefully service that special interrupt in time. No such problem ever 
with the Propeller though. 

When I first developed code for the ARM it was on the LPC2148 which I 
ended up entering into the Philips/NXP 2005 ARM design contest as the 
"noPC" with which I was bit-banging VGA graphics under interrupts along 
with SD access, audio generation, PS/2 keyboard & mouse as well as serial 
etc. That was a lot of hard work on the ARM and left very little 
processing time left for the application but doing the same thing on a 
Propeller chip is better, easier, and faster.

Perhaps you have been Googling and clicking on some very old links but 
the Spin interpreter source code etc is openly available and has been for 
years although I don't know why whether it's encrypted or not should have 
been worthy of any kind of mention.

Higher-end CPU users and those who require secured firmware should take a 
look at the forthcoming Propeller 2 due out sometime in the next few 
months or so.
 
*peter*

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Thread

Parallax Propeller Peter Jakacki <peterjakacki@gmail.com> - 2013-01-13 06:37 +0000
  Re: Parallax Propeller MK <mk@nospam.co.uk> - 2013-01-13 10:26 +0000
    Re: Parallax Propeller Peter Jakacki <peterjakacki@gmail.com> - 2013-01-13 12:22 +0000
      Re: Parallax Propeller Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-13 07:24 -0600
        Re: Parallax Propeller Peter Jakacki <peterjakacki@gmail.com> - 2013-01-13 13:55 +0000
          Re: Parallax Propeller mhx@iae.nl (Marcel Hendrix) - 2013-01-13 17:13 +0200
            Re: Parallax Propeller Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-16 06:23 -0600
              Re: Parallax Propeller Peter Jakacki <peterjakacki@gmail.com> - 2013-01-16 15:01 +0000
                Re: Parallax Propeller Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-16 09:12 -0600
                Re: Parallax Propeller Peter Jakacki <peterjakacki@gmail.com> - 2013-01-16 15:36 +0000
                Re: Parallax Propeller Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-16 10:59 -0600
                Re: Parallax Propeller Peter Jakacki <peterjakacki@gmail.com> - 2013-01-16 23:38 +0000
                Re: Parallax Propeller Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-17 04:04 -0600
                Re: Parallax Propeller Mark Wills <forthfreak@gmail.com> - 2013-01-17 04:52 -0800
                Re: Parallax Propeller Hugh Aguilar <hughaguilar96@yahoo.com> - 2013-01-24 22:48 -0800
                Re: Parallax Propeller Mark Wills <forthfreak@gmail.com> - 2013-01-24 23:10 -0800
                Re: Parallax Propeller Hugh Aguilar <hughaguilar96@yahoo.com> - 2013-01-28 17:42 -0800
                Re: Parallax Propeller "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2013-02-05 06:05 -0500
                Re: Parallax Propeller Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-02-05 08:41 -0600
                Re: Parallax Propeller Paul Rubin <no.email@nospam.invalid> - 2013-02-05 10:21 -0800
                Re: Parallax Propeller Bernd Paysan <bernd.paysan@gmx.de> - 2013-02-05 21:37 +0100
                Re: Parallax Propeller "Elizabeth D. Rather" <erather@forth.com> - 2013-02-05 10:44 -1000
                Re: Parallax Propeller Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-02-05 15:52 -0600
                Re: Parallax Propeller Paul Rubin <no.email@nospam.invalid> - 2013-02-06 00:29 -0800
                Re: Parallax Propeller Paul Rubin <no.email@nospam.invalid> - 2013-02-06 00:31 -0800
                Re: Parallax Propeller Bernd Paysan <bernd.paysan@gmx.de> - 2013-02-06 19:46 +0100
                Re: Parallax Propeller Paul Rubin <no.email@nospam.invalid> - 2013-02-09 00:11 -0800
                Re: Parallax Propeller anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-02-09 10:25 +0000
                Re: Parallax Propeller Hugh Aguilar <hughaguilar96@yahoo.com> - 2013-02-06 18:26 -0800
                Re: Parallax Propeller Hugh Aguilar <hughaguilar96@yahoo.com> - 2013-02-05 15:07 -0800
                Re: Parallax Propeller Hugh Aguilar <hughaguilar96@yahoo.com> - 2013-02-05 15:49 -0800
                Re: Parallax Propeller "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2013-02-05 06:04 -0500
                Re: Parallax Propeller Hugh Aguilar <hughaguilar96@yahoo.com> - 2013-02-05 15:21 -0800
                Re: Parallax Propeller rickman <gnuarm@gmail.com> - 2013-01-16 18:09 -0500
          Re: Parallax Propeller Ben Bradley <ben_u_bradley@etcmail.com> - 2013-01-18 21:07 -0500
            Re: Parallax Propeller "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> - 2013-01-19 10:06 +0000
              Re: Parallax Propeller Arlet Ottens <usenet+5@c-scape.nl> - 2013-01-19 13:04 +0100
              Re: Parallax Propeller "A. K." <akk@nospam.org> - 2013-01-19 13:22 +0100
                Re: Parallax Propeller Bernd Paysan <bernd.paysan@gmx.de> - 2013-01-19 13:38 +0100
              Re: Parallax Propeller David Brown <david.brown@removethis.hesbynett.no> - 2013-01-19 17:12 +0100
                Re: Parallax Propeller albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-01-19 16:45 +0000
                Re: Parallax Propeller David Brown <david.brown@removethis.hesbynett.no> - 2013-01-20 17:49 +0100
                Re: Parallax Propeller upsidedown@downunder.com - 2013-01-19 20:54 +0200
                Re: Parallax Propeller Paul Rubin <no.email@nospam.invalid> - 2013-01-19 11:04 -0800
                Re: Parallax Propeller upsidedown@downunder.com - 2013-01-19 23:05 +0200
                Re: Parallax Propeller Mark Wills <markrobertwills@yahoo.co.uk> - 2013-01-20 01:05 -0800
                Re: Parallax Propeller Arlet Ottens <usenet+5@c-scape.nl> - 2013-01-20 12:11 +0100
                Re: Parallax Propeller upsidedown@downunder.com - 2013-01-20 13:53 +0200
                Re: Parallax Propeller upsidedown@downunder.com - 2013-01-20 13:26 +0200
                Re: Parallax Propeller Les Cargill <lcargill99@comcast.com> - 2013-01-19 14:23 -0600
                Re: Parallax Propeller Les Cargill <lcargill99@comcast.com> - 2013-01-19 14:18 -0600
                Re: Parallax Propeller David Brown <david.brown@removethis.hesbynett.no> - 2013-01-20 20:32 +0100
                Re: Parallax Propeller Les Cargill <lcargill99@comcast.com> - 2013-01-20 18:08 -0600
                Re: Parallax Propeller Walter Banks <walter@bytecraft.com> - 2013-01-20 17:12 -0500
                Re: Parallax Propeller Mel Wilson <mwilson@the-wire.com> - 2013-01-20 19:19 -0500
                Re: Parallax Propeller Walter Banks <walter@bytecraft.com> - 2013-01-20 21:12 -0500
                Re: Parallax Propeller David Brown <david@westcontrol.removethisbit.com> - 2013-01-21 09:01 +0100
                Re: Parallax Propeller Walter Banks <walter@bytecraft.com> - 2013-01-21 21:11 -0500
                Re: Parallax Propeller upsidedown@downunder.com - 2013-01-22 09:39 +0200
                Re: Parallax Propeller Mel Wilson <mwilson@the-wire.com> - 2013-01-22 10:14 -0500
              Re: Parallax Propeller Waldek Hebisch <hebisch@math.uni.wroc.pl> - 2013-01-20 02:03 +0000
            Re: Parallax Propeller George Neuner <gneuner2@comcast.net> - 2013-01-19 12:29 -0500
              Re: Parallax Propeller rickman <gnuarm@gmail.com> - 2013-01-23 12:29 -0500
                Re: Parallax Propeller Mark Wills <markrobertwills@yahoo.co.uk> - 2013-01-24 14:03 -0800
                Re: Parallax Propeller Hugh Aguilar <hughaguilar96@yahoo.com> - 2013-01-24 22:55 -0800
                Re: Parallax Propeller Mark Wills <forthfreak@gmail.com> - 2013-01-24 23:03 -0800
                Re: Parallax Propeller Coos Haak <chforth@hccnet.nl> - 2013-01-25 20:02 +0100
                Re: Parallax Propeller Hugh Aguilar <hughaguilar96@yahoo.com> - 2013-01-28 17:13 -0800
                Re: Parallax Propeller David Brown <david@westcontrol.removethisbit.com> - 2013-01-29 09:15 +0100
                Re: Parallax Propeller Anders.Montonen@kapsi.spam.stop.fi.invalid - 2013-01-30 12:19 +0000
                Re: Parallax Propeller David Brown <david.brown@removethis.hesbynett.no> - 2013-01-30 21:18 +0100
                Re: Parallax Propeller Mark Wills <forthfreak@gmail.com> - 2013-01-30 22:57 -0800
                Re: Parallax Propeller Alex McDonald <blog@rivadpm.com> - 2013-01-31 10:38 -0800
                Re: Parallax Propeller Mark Wills <forthfreak@gmail.com> - 2013-01-31 12:34 -0800
            Re: Parallax Propeller Paul Rubin <no.email@nospam.invalid> - 2013-01-19 10:42 -0800
              Re: Parallax Propeller bob@bob.com - 2013-01-19 19:56 -0600
                Re: Parallax Propeller rickman <gnuarm@gmail.com> - 2013-01-23 12:40 -0500
                Re: Parallax Propeller None <vandys@vsta.org> - 2013-01-24 23:26 +0000
                Re: Parallax Propeller Walter Banks <walter@bytecraft.com> - 2013-01-25 11:49 -0500
                Re: Parallax Propeller rickman <gnuarm@gmail.com> - 2013-01-25 09:25 -0500
                Re: Parallax Propeller None <vandys@vsta.org> - 2013-01-25 21:57 +0000
                Re: Parallax Propeller rickman <gnuarm@gmail.com> - 2013-01-26 18:07 -0500
                Re: Parallax Propeller Mark Wills <markrobertwills@yahoo.co.uk> - 2013-01-27 00:50 -0800
                Re: Parallax Propeller Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-27 03:30 -0600
                Re: Parallax Propeller Dombo <dombo@disposable.invalid> - 2013-01-27 12:58 +0100
                Re: Parallax Propeller rickman <gnuarm@gmail.com> - 2013-01-28 21:38 -0500
                Re: Parallax Propeller None <vandys@vsta.org> - 2013-01-27 03:09 +0000
                Re: Parallax Propeller rickman <gnuarm@gmail.com> - 2013-01-28 21:51 -0500
                Re: Parallax Propeller None <vandys@vsta.org> - 2013-01-30 02:10 +0000
                Re: Parallax Propeller rickman <gnuarm@gmail.com> - 2013-01-30 18:32 -0500
            Re: Parallax Propeller David Schultz <abuse@127.0.0.1> - 2013-01-20 11:21 -0600
      Re: Parallax Propeller albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-01-13 16:24 +0000
      Re: Parallax Propeller David Brown <david@westcontrol.removethisbit.com> - 2013-01-14 10:51 +0100
        Re: Parallax Propeller Peter Jakacki <peterjakacki@gmail.com> - 2013-01-16 06:06 +0000
          Re: Parallax Propeller David Brown <david@westcontrol.removethisbit.com> - 2013-01-16 13:43 +0100
            Re: Parallax Propeller Peter Jakacki <peterjakacki@gmail.com> - 2013-01-16 15:27 +0000
      Re: Parallax Propeller Rafael Deliano <rafael_deliano@arcor.de> - 2013-01-15 21:10 +0100
        Re: Parallax Propeller Peter Jakacki <peterjakacki@gmail.com> - 2013-01-16 06:26 +0000
      Re: Parallax Propeller gavino_himself <visploveslisp@gmail.com> - 2013-01-22 06:26 -0800
    Re: Parallax Propeller Peter Jakacki <peterjakacki@gmail.com> - 2013-01-13 12:44 +0000

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