Born Dead #06 17 февраля 1999

Amiga     Программирование

World Amiga - Amiga eyes RRA: Basic privileged commands on the Amiga (Part 2).

                         Amigo. PART II


(C) 1999>> RRA>> / AF / SG


    Cheers! In this article I'll introduce you to the command 
system processor family MC680x0. Because I do it in the scrap, I

as ever been charged of "fire water" volume of 0.5 liters,
prudently smearing himself with two stacks of liquor
order not to abandon the writing of this manuscript.
Nizheopisany document I took not from the sky, and from 
proprietary Documentation percent of Motorola, and many thanks 
for her tovarischu Market'u of the infamous SAGE GROUP. All 
this I also seen on the Amiga in the Russian version, but the 
author seems not even tried to adjust the text converted into a

lazhovoy translation software. Napimer phrase
"Stack Window" He does not fit into my teapot
somehow "stack frame" to me sounds nice and intuitive.
Incidentally, one of those prog kind word "Amiga",
translated as "computer manufactured by Commodore", and
after such a treatment of this word, but also from overseas 
glitches translation of the text is even a very unreadable, but 
we smeyalisi not less than two hours. On the Russian version of 
I scored after reading its two lines, and relied on English as 
a handbook not giving me a lie, and as a list in alphabetical

order. I mean, it's not tracing with any document'a. How could
explained to the point. Written off only to teams working with 
modules. But the team, which I absolutely do not bychu (for 
example, cpGEN - main function coprocessor) are not described 
here. Just do not I want to compromise himself lazhovoy 
information purely translated, or lapped up from somewhere.



    So, the team will be described in two sections: basic
team and privileged (read-only mode
supervisor). Teams will be arranged in alphabetical order.
Pisishnikam and spektrumistam be a bit unusual location
operands in the team: first is the source then the receiver. For
example, consider a simple command shipment:

on the PC: MOV AX, BX - AX <- BX
on the Speccy: LD A, B - A <- B
a on the Amiga: MOVE.L D0, D1 - D0 -> D1 (pay attention to it!)

On the Playstation location of the source and receiver in each
team different and generally there for 2.3 operands in the 
team, so that Amiga is not the worst. Well, about Akseli 
PowerPC general afraid to speak, only to look at a piece of 
prog: 

loop: lwarx r6, 0, r3

      cmpw r4, r6

      bne-exit

      stwcx. r5, 0, r3

      bne-loop
exit: mr r4, r6

Personally I do not understand anything (that I copied from the 
original instructions Processor PowerPC). It says that this 
comparison and swap. So processors MC680x0 (not to mention 
iNTEL) is florets in Compared with the above monsters, so I 
think you vkurite quickly in the command system, which I will 
describe below. 

Reductions that will be used to describe the commands:

<Ea> - effective address or any way of addressing.

         "Operand of the <ea>" should be understood: the 
operand address 

         <Ea>.
DST - operand-receiver
SRC - the source operand
Dx, Dy - any sensitive data
Ax, Ay - any address register
Rn - address register or data register
MSB - most significant bit, MSB, the sign bit
LSB - least significant bit, LSB
disp - displacement

And a few words of the paragraphs describing the command:

1) Operation - the re-description of the command for orangutans 
and 

              officers. This item is consider the most blunt, 
but 

              productive.
2) Syntax - the possible kinds of records this command to the 
ACME. 

              <Ea> - any addressing mode, except prohibited.
3) Size - size of operand - a byte, word, long

              word.
4) Description - a detailed description of the command.

5) Flags - describes what may evolve flags after

              team.

6) Prohibition Addressing - types of addressing that can not be

   used in the team.

 (Description of the commands themselves will be published in 
next issue)