Re: questions (about x21)

[Greg Alexander <galexand@xxxxxxx>]

> I don't need much RAM and I want to keep everything as simple
>> (and low power...I'm contemplating powering it off of my own movements,
>> so no DRAM for me...I might even forego EPROM and have it only bootable
>> when connected to one of my other computers to download the bootcode)
>> as possible, so I don't think any of the existing boards will do what I'm
>> looking for.  I don't care much about performance, so on any other chip
>> (like the PTSC1000), I'd just run the clock lower, but I get the
>> impression that the P21 doesn't have a clock per se.
>
>No, lower the power and it will slow down. Raise power and it is running
>faster. P21 boots at about 4.75V and can be pushed to 7V if other
>components will go along. ( They won't, so 5.5V is recommended maximum. )

That's certainly one option.

>I don't think that P21 will have troubles to talk to 60-70ns FPM-DRAM
>chips. The integrated memory cprocessor is designed for that.

I'm still more interested in SRAM because then I can take the battery out
and (for a while) maintain my information.  This is rather important since
I'm not planning on having any ROM devices in it.

>> 	Also, I want more concrete details on the P21.  I suspect C.H.
>> Ting's MuP21 Programming Manual has what I'm looking for.  While I don't
>> mind paying for the thing, I would like to have something to read before I
>> order everything.  I'm a college student and $50 is still enough money that
>> I'd like to at least do some research before shelling out the cash.  I'm
>> looking for instruction set summary, pinout, maybe current draw info,
>> etc., just so I can get a feel for the chip.
>
>Of course, the ultimate web-site for you is Jeff's
>   www.ultratechnology.com.
>
>Jeff decided to offer the S21-simulator for free. Also he provides the
>boot-ROM's with tons of P21-stuff ( math's, graphics, I/O ) for free!!
>It is the P21-forth 1.02 and the newer P21-forth 1.04. They are designed
>for different boards.

All that is very nice but I have no use for compiled ROMs (I wouldn't even
if I were using the C.H. Ting board, but I'm not even sure the ROMs would
be useful at all with a different board.  At any rate, I thoroughly intend
to reinvent that stuff myself.  The S21 simulator sounds interesting but
it's not really what I'm looking for (I have never found simulation to be
useful before: if the on-chip development environment is so shitty that
it's worth the effort to simulate then I'm not going to get much done
anyways -- it's not llike I'm building an embedded system that will be
hiding in a VCR, this thing is supposed to have a good interface for
debugging).  If it has the instruction set listed in its documentation
that might be useful, but last time I looked the S21 was all based around
the F21.  In fact, everything on Jeff's site provides very much
information on the F21 but practically nothing provides any info on the
P21 (definittely not anything detailed and definitive) and I didn't see
anything listing differences (i.e., are the instruction sets the same?)
	I want current draw information, pin out, instruction set.  When
this information is provided to me I will buy the P21.

>Dr. Ting provides best service, talk to him! The MuP21-manual covers a lot
>of stuff and covers different versions of chips and testboards. It maybe
>very confusing when studying the manual on its own.

Does the manual include all of the information I'm after? (current draw,
pinuot, instruction set)  If so, I'll just buy that and consider myself
dealing with your commmon semi-proprietary company that proudly
misunderstands the hobbyist customer base.  (even Intel publishes data
sheets online for free!!!!!!!!!!!!!!!!!!!!!!)  !!! !!! !!! !!!! !!! JEFF
FOX READ HERE EVEN INTEL PUBLISHES DATASHEETS FOR FREE (and I'm not
talking about tshe F21 here!)!!!  I've not even had too much trouble
finding them.  If I'm not going to get the level of developer support
for a develooper-only chip like the P21 that I would get from a consumer-
targetted chip for the x86, then I don't know what yuo're thinking.

>If you are really going to explore P21 in order to get a feeling for these
>chips ( I started that way, too ) feel free to contact me. I can send
>you a lot of stuff to start with. 

Thanks.

>I'm still so excited about these Forth-engines. I have much fun and learn
>a lot and I have real hardware meanwhile. So I can test nearly everything
>on these chips and it convinced me even more, that Chuck's design
>methods are outstanding. I love these little toys a lot! ;-)
>
>I deeply admire Chucks's obsession in getting the most out of a
>small piece of silicon and Jeff's and Dr. Tings research and engineering
>efforts to bring up MISC-computers. Thanks to them.  

Yeah, I'm really glad that they did all this stuff.  It's some oof the
most interesting stuff happening.  it's just extremely frustrating to see
that they've doone all the hard parts (design, implementation, fab,
testing) but they've messed up on the easy parts (providing enough
documentation so that a low-budget hobbyist could mmake an informed
decision).