DonNews #12 09 сентября 2000

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NEOS - The story the authors of the operating system.

       New OS for Spectrum or NeOS

--------------- Xtrimer aka Aztec Graphics

   Our team went to such "cruel"
step, given the urgent need to
new core for the Spectrum. At first, everything was
somehow spontaneously: we have not looked at the BIOS and
on NeOS, as the serious food. Only
seeing them for some future, we are really close interest in 
these projects. And especially now, with the advent of new 
computer modifications (extended Screen 512 x 192, 16inks, 
16papers, 16borders, switching screens, without blinking) a sin 
not to use the full force.


    To be more precise and close
relate to the theme articles, we can say that
written BIOS (Basic Input Output System) -
kernel itself, the simplest OS (Operation System) - NeOS, which 
already can work with disks, memory, screen, etc. and of course 
a full OS - Studios (Tm). If the first two more or less clear 
(about them below tells Megus), then Studios (tm) - is a 
graphical front (Library, as you like), which supports 
psevdomnogozadachnost, work with absolutely any device, has

attractive appearance and is fully
written under NeOS (so severe last
restriction imposed on it due to the revolutionary ideas 
NeOS'a). Because our task at this stage consists of writing and 
support for the kernel and operating system. And as exemplary 
features of the new OS - Studios, I will cite only a small part 
of the planned: 

 - Psevdomnogozadachnost
 - Will be protected from failures
 - Works with most disk systems
 - Its disk system
 - Easy to use graphical interface
 - Simple installation and support
 - Scalability (ability to

   gradual addition of new

   components)

Megus of Brainwave Association ----------
    This article is rather brief
review of the new BIOS for the Spectrum. Immediately
make a reservation, but lest there be misunderstanding -
written not only the BIOS (system functions)
but the simplest OS, working with this BIOS, dubbed NeOS.

    The idea of ​​creating a new BIOS for the Spectrum
ferment in the minds of many people, already
long enough. Only here one for some reason did not start 
serious work on the project, and the BIOS remains only at the 
level ideas and thoughts about how cool it all

be. Perhaps the only one then
dare to go beyond zadumok, Paul was
Fedin. He led the work alone, but after learning about
his project, I decided to help him. The result of our brief, 
unfortunately, were some specific cooperation ideas to 
implement the BIOS. One of the major decisions was the idea of 
​​placing the BIOS ROM and not in RAM, as is done in IS-DOS. Was

decided to remove the BASIC ROM 128, putting on
his place BIOS. This ROM is still one
not used, as well as by the 128
BASIC, so the loss of this part of the ROM is not
would affect compatibility. Decision
BIOS is placed instead of 128 BASIC, but not in the free page 4 
of the ROM was for two main reasons: on some computers, the 
fourth page is already occupied (eg in Scorpio), but for most 
machines on which the page is free would require a hardware 
revision, allows to include this page. We

would like to install a new BIOS required minimum hardware 
interventions (replacement ROM can make each). 

    This is our Pasha Fedin promising cooperation did not last 
long, so how people in different cities

(Moscow and Yoshkar-Ola) and communicate only
by FIDO, to work together more difficult. Therefore, work
BIOS stopped, however, and I and
Pasha were some achievements. So would
perhaps the idea of ​​the BIOS, and bent, if not
development of networks based on the Spectrum. For writing 
network software for networking, especially with FIDO want a 
convenient and powerful system to work with files. TR-DOS 
provides no such facilities, so as not a full disk system. That 
is why the authors of the network software has all the 
convenience of working with files to implement themselves. And 
since these authors are not alone, then all of them have to 
travel this work. And often the main time is spent on writing 
the file system name, and not own program. Deciding to 
facilitate the work of authors, we decided to resume work on 
the BIOS. The truth now Pasha Fedin not participates in the 
work, as he gave up on this idea. 

    Such is the brief history of the idea of ​​creating
BIOS for the Speccy. Now a little about what
It gives the programmer and the simple user.

    BIOS is written primarily for programmers who develop 
primarily complex system programs. However, the BIOS

may be useful not only for writing
sistemok, it can help when writing
games, and possibly demos. The basic idea BIOS
- Solve the problem of different nerovmestimosti
Spectrum models. In general, they are not compatible in terms 
of management more memory (greater than 128 kilobytes), but 
there are also difference in some other areas, such as working 
with hard drive, with CMOS and etc. BIOS will be different on 
different models, but the functions remain the same only 
another unfulfilled. Therefore, one of the conditions of 
writing programs for BIOS is the fullest possible use of its 
functions. The function is implemented by BIOS restarts - calls 
to fixed addresses in Rom. Each restart is responsible for any

a group of functions. Functions are divided into the following 
groups: 

 - System-wide functions;
 - Options to the screen;
 - Circular functions;
 - Features the work of memory.


    To work with any external devices realized the system 
drivers with which is carried out and work.

For certain classes of devices (mice,
keyboard, disk systems) will be determined standard features. 
Thus solve the problem of compatibility of mice,

keyboards, modems, etc. In addition, BIOS
becomes a multisystem (in terms of
discs), then there is no difference with what
the disc format you're working, the main thing that
a driver for this format, which ensures correct operation.

    BIOS relieves programmers responsibility to maintain the 
extended memory of all machines (or deprive the owners of other 
machines), different types of mice, etc. And users are deprived 
of the headache associated with question: will go to his car any

program, or would not. All programs
written by BIOS, and written
correctly, should go for all types of machines that are running 
this BIOS (of course if the resources of this machine is 
sufficient for run the program).


    Now a small review of the simplest
operating system, which will also be
located in ROM. NeOS's just a shell, which includes most 
necessary for team. In addition to the teams work with the disk 
he has a command to the screen, memory, and

others work with the interpreter can not
only direct input commands
keyboard, NeOS allows them to perform well
called batch files, representing
from a simple text files with commands NeOS. Since NeOS 
provides minimal comfort in the work, which is enough for more 
serious use of it, the package delivery will be include two 
versions of the shell. The first is for the ordinary users who 
are not involved in the development programs for NeOS. In the 
second version will be added to the team, facilitating the 
development of programs. 

    On this, perhaps I will finish this article. On all issues 
related to the BIOS and NeOS, you can get answers by contacting 
us. 


    Technical questions and suggestions:

  Tel. (8362) 22-66-09, 19:00-22:00 (Msk)

      424019, Russia, Yoshkar-Ola

      st. The festival, d.77, kv.13

           Roman Petrov (Megus)


         Organizational matters:

  Tel. (8362) 22-60-05, after 21:00 (Msk)

      424019, Russia, Yoshkar-Ola

       st. Yvan Kyrlya, 21, kv.7

         Lezhnin Dmitry (Xtrimer)


     2:5052 / 7.37 @ Fidonet (Subj: BIOS)