World: r3wp

That one gets the type and put it in result. And that wasn't what 
you asked, I just realize. :) Let me think...

>> ex: rebcode [/local a][set.i a none eq.i a none ift [print "a 
is none"]]
>> ex
a is none

Above example done under Windows with: REBOL/View 1.3.61.3.1 18-Nov-2005 
Core 2.7.0

In rebcode none is same like zero so if you want to check value where 
are integers or can be none, than it's not enough. The best way how 
to solve it now is not to use such a logic, or use something like 
this:

   ex: rebcode [a /local r n no][type? r a print r   set n none type? 
   no n  eq.i r no ift [print "a is none"]]

which is quite heavy. Or find out the integer value for each datatype. 
Or is there any better way how to work with value returned by  the 
type? opcode?

type? none is in rebcode integer 28 so to test none value it's possible 
to do:

r: rebcode[a][type? t a  eq.i t 28 ift [print "a is none"]] r none

I found it using this: r: rebcode[][set i 0  set n none type? n n 
while [lt.i i 10000][eq.i i n ift [print i] add.i i 1]] r

I feel, the main goal for rebcode implentation is speed, so it makes 
sense, that none is the same as zero. It would probably hit performance 
a lot, if you had the usual REBOL datatypes in rebcode.

Maybe it's confusing, that rebcode has NONE at all!?

Maybe it's confusting that something as basic as NONE? doesn't have 
a corresponding opcode.

Ready for some fun?

Here's a MOS 6502 emulator written in rebcode, I made over the last 
few days:
http://www.fys.ku.dk/~niclasen/rebol/language/em6502.r

Geomol: you are crazy !

And no, you can't play Elite with it! ;)

I made this to test the speed of rebcode. That's my primary goal 
with this. So there is no Operating System stuff of any kind, so 
no I/O for keyboard, joysticks or screen.

Guiseppe: I know! But shhh, don't tell the others!

It's v. 0.9.0, and I didn't call it v. 1.0.0, because it needs some 
more testing, I think. It's GPL license.

Well, I am at the command prompt, I did a do http://www.fys.ku.dk/~niclasen/rebol/language/em6502.r
and the prompt is here again. What could I do ?

It require REBOL/view v. 1.3.50. That's the rebcode version, I used, 
because it's the one, that run on most platforms.

is there any ram file to test with?

Nothing ! I want to play Last Ninja 3, how could I do this ? :-)

To make a little test:
do http://www.fys.ku.dk/~niclasen/rebol/language/asm6502.r
do http://www.fys.ku.dk/~niclasen/rebol/language/em6502.r
ram: asm6502 "lda #&01 adc #&02"
em6502 ram 0

Those 4 lines do this: load the assembler, load the emulator, call 
the asssembler with a 6502 asm program returning 64kb ram, and finally 
run the program.

Why you are using the old and slower rebcode version?

Not much to see, but the program ram. To check things, put e.g. print 
lines in the end of the emulator. Like those 2 already in there commented 
out:
print A
print P

which will print the content of the A register and the P (status) 
register.

Oldes, because that's the one I have under OS X.

how sad:/

I think, we can convert it to the other version with one of (I think) 
Ladislav's scripts.

Yes, there is a script called convert-rc.r by Ladislav Mecir.

And what's the result of your test, how fast the rebcode is?

I only did very little test so far. I got around 1.5 MHz. The cpu 
(actually a 6512, it seems buth with 6502 instructions) in the BBC 
was 1MHz.

I plan to do more tests in the coming days. Or maybe some of you 
wanna test too!

Script Error: rebcode has no value

And this is on a 1.2 GHz G4 powerpc on my iBook.

Guiseppe, make sure you run rebol 1.3.50!

I am running view 2.7.5

You must have version with the old rebcode

only 1.3.50 and one more version has rebcode. not later versions

Ok, I will try later

This win version should work: http://www.rebol.net/builds/031/rebview1350031.exe

OS X version: http://www.rebol.net/builds/024/rebview1350024.tar.gz

Linux version: http://www.rebol.net/builds/042/rebview1350042.tar.gz

For 6502 asm documentation, I use the "BBC Advanced User Guide" found 
here: http://www.nvg.ntnu.no/bbc/docs.php3

I'll see, if I can make a good ram-file to test with. And maybe a 
little wrapper, so it's possible to monitor, what's going on in the 
emulation.

Oldes, the older rebcode version wasn't slower, it just had less 
features. We had to change the naming convention of the opcodes to 
add the features.

Just to clear things out regarding performance. This is an emulation 
of a 1MHz cpu. It requires quite some computing power to emulate 
another cpu. To give a hint: an instruction line INX, which increment 
the X register by 1 requires 2 cycles on the 6502. So you can do 
half a million of those instructions on a 1MHz 6502 each second. 
In my emulator, that INX instruction become 11 rebcode instructions 
plus 6 rebcode instructions to control the loop, a total of 17 rebcode 
instructions. And it takes less than half a second to do 1 million 
of those, which is like a 4MHz 6502. So with this initial test, I'll 
say, rebcode is useable.

John; still can't get into 6502.org but the site holds quite a bit 
of source code, from snippets to floating point math by Steve Wozniak.

A first version of a MOS 6502 workbench tool is ready:
do http://www.fys.ku.dk/~niclasen/rebol/language/m6502wb.r

It'll load the 6502 assembler and emulator. It's a tool to compile 
6502 assembler programs to machinecode and run it with the rebcode 
emulator. It's possible to see the 6502 registers and flags. Both 
asm6502.r and em6502.r has been updated.

You'll need REBOL 1.3.50 to run this!!!

Scroll the 65kb ram with arrow-keys, page-up/down, home and end.

It works like this:
1) Write some 6502 asm in the text area. Example:
lda #&80

2) Press the button "Assemble". Now you can see the opcodes in the 
ram at address 0000.

3) Press the button "Begin" to run the emulator with the produced 
machine code and see the results in the registers and flags.

Hm, probably a bad idea to use arrows to navigate ram, because it 
makes them not work in the text area.

A performance test program:

lda #0
sta &1001
.l1
lda #0
sta &1002
.l2
lda #0
sta &1003
.l3
lda &1003
adc #1
sta &1003
lda &1003
bne l3
lda &1002
adc #1
sta &1002
lda &1002
bne l2
lda &1001
adc #1
sta &1001
lda &1001
bne l1


It takes 40s to run on a BBC emulator emulating a 1MHz 6502. It took 
around 14s using the rebcode emulator on my 1.2 GHz G4, and it took 
9.5s using the rebcode emulator on my 2.4GHz Pentium 4.