ZX Time #06 09 января 2002

Концепции

Forum - Multitasking and OS.

Forum


                                Readers


  From the Editor: I remember at the very beginning one of the 
readers suggested organize under ZXTime some semblance section 
"Forum" from the ZX-Revue. First I have ignored this proposal, 
justifying himself by the phrase "Who can we write about will 
!"... But times have changed and today We already have a pretty 
decent luggage messages and themes for discussion. And now I'm

sure that readers will not be ignored, this initiative ... Yes?


   A topic of discussion today is ...


          Multitasking and OS


 The first floor is given cr0acker2:


  Here I decided to write on a multitasking operating system. 
In general, multi-tasking OS Speke pond pond. The earliest was 
the best. It was a DOMAIN OS. She was very well spun. Look 
magazines 96 years. There's all just talk The domain of the 
sprinters and wasps. She stuck other processes are already 
working, but waiting for input from the clave. And braking 
trdosovskih programs there were no more 2,550 percent. Yes to 
the axle a lot of adapted TR-DOSOVSKIH programs.

Why did she lose? I can not be
rights, but the main reason LAZINESS author.
The author struggled on the mortgage to release their OS
for sprinters. But that's not running for a sprinter, not an OS 
for the Spectrum. Understand OS raspostranitsya only if

she or her portion will be stored in Roma.
Modern Roma accommodates about
512K. Schema only need a rum
Connect! Now you're here talking about that
OS should be every time interpitirovatsya.
It will be very funny. On account of the language I
came to this conclusion. The language should be
C. With beautiful language though I do not
love. And this is a bluff that the cake is not enough
might work on C. I have a HT there
Minix and worth every day I use
gcc. Moreover, in HT 640KB memory. And the cake
48 - 4096. In our country walks with three versions: HiSoft C, 
another version of a peasant, and not always produced version 
RST7 (Uncle RST7 well, and where is your C?). Most normal

of them Hisoft C. But it has not received proliferation because 
of its 48sti. I think it becomes usability if you make changes 
in the following items: memory support 128256-512-1024-4096 
interface ALASM-like, Editor pozvollyayuschy edit

text on the entire file into TRDOSE (ACEDIT),
support 80 characters for the three schemes,
Alco, PENT, 8Profi, may make
support for GMX. It's all needed in the
compiler. In principle, having such
compiler can not write anything of his own, and the same port 
Minix. Now, iron ... I think the minimum configuration of OS 
should be 7Mhz-256 and the kernel should ponostyu, together 
with the Drava and the API to accommodate a 128 kb. When 512 is 
More something is located. And when 4.1 MB ... The memory must 
rameshatsya the entire disk, but will he? Now for what the car 
needed to navigate ... I think that we need to focus on 
manufactured cars. As far as I know now produced two cars: 
KAY1024 and Sprinter. Need to do two versions of the OS

kai and Sprinter. And that they were flying and
by Kaye, and Sprinter. In Sprinter wasps
shall be operated Sprinter. Now the graphics core. It should be 
based on three graphic gadgets: 


  1) the main mode: NO BORDER (Alco
scheme);

  2) Hardware Multicolor;


  These two gadgets can make yourself
each. They are very easy to do.


  2) the advanced mode - this is high
expansion of penta and profiles, as well as GMX
scorpion fish. We all need to twist Sprinter
at 640x200. OS should be sewn into the bios.
And it is an axiom. Otherwise it will fail. AND
last - the OS should have the TOOLS for
odaptatsii TR-DOSOVSKIH program to the OS.


  Well, that's all I wanted to say ...


                 - - -


  Following opinion came from Sinus'a of
Savers Alliance ...


  In Zx Time 4 was an article about multitasking with something 
like this sense: there are two bend in the memory, switch them 
to interrupt. Once I did so: brakes creepy. imho better to do 
on the principle of preemptive multitasking. If not

set prog priorities, it is
can be realized at Speke. So: suppose there is some 
multi-tasking operating system (and not pIS-DOS) window type 
(ex. WICROSOFT (R) MINDOWS (TM), Work Bench,

OS / 2, MacOS, ...). Further, for clarity
bring a piece of code:


   org # c000; start the program with # c000,

               , So you can keep

               ; A lot of prog in Banks


   ld ix, Wind; address window handle

   call wOpenWindow; open the window

   jp wMain; and jump to the OS

windowFunc; window function;)

   bit wPRESSED, C; whether USER has pressed the Settings button
                 , Ku?

   jp z, wMain; if not, then jump into the

                 ; OS

   cp # ff; if you click Cres
             ; Tick "(like" close window ")

   jp z, wCloseProgramm

   cp 1, the first button (CLOSE)

   jp z, wCloseProgramm

   cp 2

   jp z, # 0000 and the second button ('RST 0')

   cp 3

   call z, changeBorder; button (BORDER)

   jp wMain

cnangeBorder

   call rnd

   out (# fe), a

   ret

rnd ......

Wind db 5,5,10,20; x, y, h, l

       db "Test window", 0; window title

       dw windowFunc; address of the program
                       ; Processing


       db 1, wBUTTON, 0,0, "CLOSE", 0, number

                       ; Item type

                       ; Element, x, y,

                       ; Name


       db 2, wBUTTON, 0,2, "RST 0, 0

       db 3, wBUTTON, 0,4, "BORDER", 0

       db # ff; the end


  Now try to explain all this
delirium. How much of the bend, no longer
prog importantly, on the contrary, the window now
runs prog. Now the main idea: to
Operating system in turn calls windowFunc each window. If the 
program (as in the example) nothing else, it simply passes

running, or doing a quick
what we need, and, again, passes control to the OS. And so each 
application. In Consequently, if the user does not

does, and the prog does not spend on it
his precious clock cycles. And if he pressed in any window, 
button, only the application and react. And if necessary, until 
the user is doing nothing or working with another application 
something to count, then slightly modify windowFunc:


windowFunc push af, bc, de, hl; save

                            ; Registers

           call myProgCalc; something de
                            ; Barking

           pop hl, de, bc, af; recover

                            ; Registers

           bit wPRESSED, C ...

           ....


  Attention! That there was no such wild
brakes, as in windsurfing, the procedure
myProgCalc should be as
faster.


                 - - -


  Well, that's the whole "forum" for today. Now I'm passing the 
word itself:) (DWT). Immediately I want to say - "Forum" - a 
section purely library. Can bring up absolutely any topic! Some 
thought to the account of a can also send a "Forum". In 
general, give section "Forum" in your hands, readers.



  The only request: If your letter
oriented in this section, the so-
it (the letter) and mark (say, "In
Forum ").


                 *