No Subject

[jfox@xxxxxxxxxx (Jeff Fox)]

>Hi All,
>        Could someone (Jeff?) post details of what you actually get in the
>$350 development system and the $100 kit. And how do you actually run it. Do
>you need to use the on board video other than to refresh the dram. Does it
>come with some sort of PC host software like the Novix did. 

The $350 system is fully assembled and has a simm.  The $100 kit is a board,
MuP21, UVPROM, and I think a part list and manual, and diskette.  I
don't think you get all the sockets, xtal, resistors, etc in the kit.

It comes with the OK menu system and its boot code and video code on the
rom.  It boots up and is controlled by 7 buttons.  It has menus, demos,
graphics, hex dump, and some of OKAD, as demos and examples.  You
connect 8 buttons (one for reset) and a monitor, and power.  The
software source is for DOS under an FPC version of Chuck's assembler
for MuP21.  So you get Chuck's Forth assembler with OK as an
example and library of routines.   You can also get a different
assembler from Robert Patton, or the P21Forth compiler (with its own
assembler).  Chuck's and Bob's assemblers run on the PC to create a
UVPROM or PCMCAI card boot image.  Dr. Ting also includes a routine
to convert vga graphics to P21 graphic images to be loaded into the OK
demos.

The P21Forth can use a parallel or serial keyboard.  So you can use a
PC as host as was done on the Novix kits.  I am still metacompiling 
the P21Forth on the PC, but I am porting the source code and the
minimetacompiler to the chip so it can metacompile without the PC.

>Another thing that isn't obvious is whether the chip can be slowed down so
>you can use slower drams? I've read that the xtal is only needed for video,
>one could interpret that as meaning the system clock is internal, though
>this sounds unlikely.

The CPU is NOT clocked.  It runs as fast as it can and is only limited
by how fast and how often it gets access to memory. 

Slower than 80ns?  No I don't think so.  The CPU speed will be
more or less proportional to voltage.  It does slow down at 3 or
4 volts, and goes very fast at 6V, but so do the RAMS.  The
memory interface on MuP21 is not programmable.  It generates
timing signals for 80ns DRAM and 15ns SRAM and 250ns BootRAM.  You
could use cheaper 256kx4 DRAM, but I don't know if you can get
1 megabyte simms in the 72pin package.  Also 256kx4 DRAMS only
have 512 word pages.  So the address space would not be normal. The
upper half of every K of memory would be a copy of he lower half.
I did write a version of the metacompiler that would generate a
system for a target like this.  You could get 640K bytes of DRAM this
way for about $25.  But there are problems with using them on the
present boards and the software is a little strange.
 
>Thanx Eddie.M.
>
>
>Edward Matejowsky.
>Queensland University of Technology
>Centre for Eye Research
>email E.MATEJOWSKY@QUT.EDU.AU
>Wk +61 7 864 5731 Hm +65 7 2825382
>
>There is nothing permanent except change.

Jeff Fox
Ultra Technology