Newsgroups: comp.robotics
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From: jfox@netcom.com (Jeff Fox)
Subject: P21 Forth kits was Re: Forth's reputation
Message-ID: <jfoxD47Iso.C4s@netcom.com>
Summary: correction of details
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References: <6.14254.723@spacebbs.com> <3i1i0a$irq@hopper.acm.org>
Date: Sat, 18 Feb 1995 17:48:24 GMT
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In article <3i1i0a$irq@hopper.acm.org> ANGELUS@PASCAL.ACM.ORG writes:
> / /
>I think the cost of an evaluation board is only $300.  It has to use only the
>fastest RAM for obvious reasons.  We plan to offer a CPU based on this chip
>later in the year.

The minimal configuration is a P21 chip and a UVPROM, however this is not
enought for the processor to generate a video signal.  There is a 
kit for $100 with a board with chip and that can use a DRAM SIMM. 
The CPU can load and execute up to four Forth instructions in each
memory fetch, so 80ns DRAM can support up to 80 MIPS without cache
or a cache controller.  If you go with 15ns SRAM you can run at 100 MIPS
on some code sequences.  But the neither the kit board or the development
system board are socketed for the 15ns SRAM parts.  The assembled kit with
the 14Mhz clock for generating video and DRAM SIMM is $350.  Both versions
of the kit come with Chuck's assembler and code to set up the video
processor to 384x482 pixels in an NTSC format, and link graphics to the
menu system in his OK software on the boot prom.  There is also an
ANS Forth available on prom for the kit, and there will be more.  I
hope we will see some PD board designs available cheaply via the net
some time in the future.  :-)
The P21 does not have an external interupt, and the closest thing is
the clock for the programmable analog output processor that generates
the video signal.  So P21 does not have the external interupts and
timers and A/D or even the onboard ram or rom that people find so
very useful in microcontroller based robots.  But P21 does offer
more computing power per watt or per buck than many other alternatives.
I also like the video output from the processor.  Things like a GUI
or visualization of a robot's perceived environment and advanced
diagnostics are things that I think will be very useful in cheap 
battery powered robots.
Chuck is now in the custom silicon business.  So he will be designing
variations and perhaps some will be what people want for some
robotics applications.  I know the idea of a P8 with some of the
more conventional microcontroller circuits on chip sounds like a good idea
to many people.
Robotics is one of the targets for the F21 processor in development.

Jeff Fox

