(C) 1998 VY Chertkov
Music: THE BEST ITALIAN-'VENICE 'by KENOTRON
ZX-Spectrum and operating system (OS)
More recently, asking anyone spektrumyuzeru question:
"What is an operating system for Why did she want? ", you could
get the answer: "I do not know!" And it is not surprising,
since ever existence, on the Spectrum never had OS
fully understood, because it was originally a computer
conceived as a game. As in all such
PC, at the Spectrum instead of the OS was installed BASIC in
ROM, as This language has the basic features inherent in
operating systems. But Spectrum BASIC is very primitive, does
not support disk, press tokenizirovany (very poor syntax), and
develop it further is extremely difficult. ROM Spectrum is
built according to the "monitor" - there are no functions
available to the user devices to service a computer with a
single interface (in normal computer is called the BIOS or
Kernal). There is only one standard entry point
Monitor (restart) - everything else described in
various literature on the Spectrum - a sub-program monitor, and
nothing more. Ie, ROM is a "black box" which can not climb.
Unlike the computer that Yamaha. Model
MSX-1 is also, like ZX-Spectrum has only BASIC in ROM, but the
Basic is much steeper than Spectrum and imagined future use
drive. In addition, it is similar to Microsoft BASIC,
but greatly expanded - supports graphics
(Sprites) and sound (AY). In addition to BASIC, the ROM
contains the system BIOS, and it gives the opportunity to
develop all the basic software with no loss of compatibility,
since No one inside these programs does not climb - there are
standard entry point. In general, their own
ROM has every device (RS-232, RTC 'CMOS).
Program tied to any external events (input-output to tape I / O
RS-232), not synchronized program delays CPU, and based on a
real time clock, ie on CPU speed correctness of the drivers are
not independent (compare with the Spectrum). Moreover, the
functions BIOS available to the user's software - it's just
wonderful: firstly, there is independence on the equipment, and
secondly, to write programs much easier, because all low-level
I / O is already created!
In the model of MSX-2 was without problems is running
MSX-DOS, ie, computer worked without the BASIC, though, if
desired, it can be run on the OS commands. After restarting
computer, in the absence of a system disk in the drive, also
carried out in BASIC. Ie without OS computer looked like a
normal MSX-1. But Basic was already a disc - all teams to be
forwarded from tape to disk (without any RANDOMIZE USR 15619:
REM :....), although the possibility of working with cassette
remained. Old tape of the program worked fine from the disk,
they did not have to be adapted to great difficulty, both on
the Spectrum in TR-DOS, their had to just copy from tape to
disk - and all!
And I said all this to the fact that if Spectrum has been
designed as a human, then many would problems now did not
exist. No need to kid ourselves, not even in the hardware
capabilities of the case, the underlying ideology of the
computer is outdated! In the form in which there is now a
Spectrum, it pointless to develop - the next revision will not
change anything, on the contrary - the car will be even worse.
Looking for a qualitative change. After all, the Spectrum was
developed as a cheap gaming computer, but we are now with him
cope, as a professional machine. Even Clive Sinclair himself by
1984 had lost interest in him because he was already obsolete,
but we're still sitting, and that is trying to from him to do
....
Almost as primitive as the ZX-Spectrum
48, were his competitors - C64 and Atari. But these
firm in time changed his mind and released the brand new 32-bit
model, having nothing to do with the old 8-bit. 32-bit Spectrum
QL failed, of course, very sorry ... For the development of the
new ZX took firm Amstrad, firing again very bad model Sp128 +,
+2 and +3. They are very not far removed from the Spectrum 48,
while the price has increased significantly - the sales speak
for themselves. A after all there was also an opportunity to
make a good, albeit 8-bit, the new Spectrum. Would take the CPU
Z-180 or Z-280, which almost fully compatible with the Z80,
at the same time more productive and memory addresses
1MB and 16MB, respectively. Some programs on
These processors would not have gone, but no great loss.
On a new PC can be fitted normal OS
to support the older programs can be done
something like an emulator, though, if you look at it
up to 1985 good games, we can say never happened.
Yes, many things could be done. Instead,
concocted something called Spectrum 128K - apparently developed
this "after yesterday." What was done in this model - it is
done hastily and not the best way. In the same wells and the
memory is addressed more convenient, and there are no such
restrictions, as Spectrum ...
Recently, many electronic publications raised questions of
further development Spectrum, the comparison of different
models for "Slope", and some places have begun to realize that
the OS in general, it is necessary. And asking someone whether
he heard about operating systems, you can get the answer: "Did
you hear, hear" - referring to the TR-DOS, iS-DOS, CP / M or
MS-DOS. But, first things first.
The fact that the TR-DOS in general is not an operating
system, written even in the corporate governance (read
instructions can sometimes be useful) it's just a disk
interface. When conceived this interface, the main task was to
approximate it to the cassette, ie, that all operations were as
much as possible like the similar "cluster". The meaning of the
interface - just broadcast Cassette I / O to disk. But even
that turned out pretty poorly - everything needed to redo the
program, and relatively easy to distilled Only the most simple
program loader on BASIC. Funny, but when craftsmen recreate
BETA-DISK for "our" spare parts, apparently for reasons of
compatibility with the ROM in 1990, the window entrance to the
TR-DOS was shifted to 256 bytes forward - at the beginning of
character generator (at address 3C00H on 3D00H). It is easily
seen by looking at software, "throw" Multiface-128. In the
"old" BASIC such programs, it happens, stays loader, where it
is clear that TR-DOS command is invoked like:
RANDOMIZE USR 15363: REM: LOAD "file" CODE
On this basis, it becomes clear why
no one (!!!) program TR-DOS, which came to
us from the West - they just did not work. Another interesting
fact is that the beta-disk - this is the worst of disk
interfaces ever created for ZXSpectrum, and he settled down
with us! And even in an erroneous implementation. What do we
have a country that survives only in her worst ???....
And, in general, TR-DOS reminds the Monitor Spectrum, ie
has the same shortcomings. At the same time occupies entire 16K
- although such a "system" and 2 kilobytes much. Challenges for
3D13h - it's not BIOS (Ie, primitive, even for BIOS) and much,
much less DOS. If you're not lamer, you will agree with me. As
and BASIC, ROM TR-DOS to develop practically impossible - to
begin again the problem (in) compatibility.
Another thing iS-DOS - goes for any Spectrum, works pretty
fast, here are some screaming: "iS-DOS - Best Of The Best !!!!"
- Not fully understanding the meaning of these words. Although
she quickly separates file panels, working with
sub-directories, has external command, etc. In general, creates
the illusion that your computer is running the OS, but it's
worth a look in the programmers' manual - as all will become
clear - it is just a wrapper, empty, You blatantly cheated! No
OS and No trace. And if you're taking this leadership will come
to more or less prepared for the programmer Amiga or PC, and
start him to prove that the iS-DOS the operating system (I'm
not talking cool) then, at best, he wagged his finger to his
temple (Or call 03). All that is there - a set of functions for
drawing windows, text output and input characters from the
keyboard. File Subsystem (Part Operating system, manage files)
is missing completely. Also, there is no memory management
system, what is done - is in its infancy. And if it is compare,
for example, MS-DOS, then this level of BIOS, ie simple device
drivers. Yes, and how drivers they are defective: there is no
clear structure, uniformity of input and output parameters,
connectivity, custom drivers (like on PC). In normal system,
all low-level procedures constitute the system BIOS, and to
connect the extensions (plug-drivers), there exists some
mechanism in the iS-DOS is a mess. No not that clear, in
general there is no structure, And it is with the structure and
begin to write the system .... Before writing the OS, you must
first work hard to know what it is and how it works.
I remember how they told me this system bummer. After
reading in the advertisement: "... The newest operating
systems! ... Subdirectories ... just can not believe this is
unbelievable!" - Of course I was delighted and immediately ran
to the post office to order the basic kit (in Inforkom, of
course). Imagine my disappointment when I was at all
it looked - it's just indescribable. So break off! Even
formatter was not, but, by the way, this basic set, I copied
the first same day they are even the same utility ARZT (or a
Doctor, not I remember already, as it was called), such that's
the case.
I certainly have nothing against the authors
this program - they did a great job, but
Unfortunately, all for nothing ....
Now we discuss the system CP / M. Many
(Not all, of course), who saw the CP / M to the pros, why
is convinced that CP / M - is the actual panel file shells
CopyK, although it is certainly not the case. Interesting, but
similarly judged and the MS-DOS shell to Norton Commander.
Seeing how slow CopyK, many will say: "CP / M - this shit!".
But it all that CopyK - it's just a program running
under CP / M - and the fact that she ugly napisanz does not
mean that the CP / M system is bad. It just means that CopyK -
brake program! And CopyK we must pay tribute, in a time when it
was written (92-93g), on the Spectrum nothing (!!!) this was
not observed, although generally it and now the situation has
not changed much.
OS CP / M - is an add-on equipment
computer, the intermediary between programs and devices. At the
disposal of the programmer is a set of functions, which greatly
simplifies writing programs. Those who disketiroval game in
TR-DOS, they will not believe how easy it is to work with
files, even in standard CP / M (on the extended versions, I do
not say). System provides ease and convenience working with
file structures. Program, working through the CP / M, will work
on a floppy disk, a screw or electronic drive - to work on
another device, it should just go copy and do not need to redo
it. Complex manipulation sectors, tracks, teams controller - all
it takes the OS. You do a direct solution of the problem,
rather than recreate some parts of the OS at each program (as
is well known, qualified in all different programmers ...).
* TO BE CONTINUED *
fragments of the OS at each program (as is well known,
qualified in all different programmers ...).
* TO BE CONTINUED *
vobodnoy from the intro of
- Why?
- I do not know!
(C) 1998 VY Chertkov
Music: SPECIAL COMPOS 'by KENOTRON'96
ZX-Spectrum and operating system (OS)
(Continued)
Now for the visual comparison of the systems. The point
that "see" the operating system can not, ie
because this is just a set of functions - is not a program such
as musical demonstrations - which draws chtoto on the screen to
the music - it's not something ... System can only be assessed
on their abilities (Both existing and possible future).
Although, like it is! The magazine ZX-Format N4 Nemo,
reflecting on the Spectrum, gave a comparison of existing
systems to ZX. We compared the CP / M, iS-DOS, TR-DOS and MagOS
(!). Nemo, not stupid like a man, a good article says, but he
thought of comparing CP / M with MagOS? It's like comparing a
scooter with a "nine". After all, people are not very versed in
this, after reading the article have thought that the program
MagOS on Scorpio - is a system comparable to the level of CP /
M. The same just wild! And indeed, in this series CP / M - is
the only operating system, so I do not understand how they can
be compared.
Despite all that, in comparing these systems
won, what do you think, what? Yes, all right,
iS-DOS! In CP / M, it appears, and the interface is not (I
wonder how it all works then?), And segmented, and "long"
files. You are wrong, all it is, why it can not not be. The
only thing the human Nemo - subfolders in the usual CP / M
actually no, but there are areas of the user - USER'y. I agree
that working in the command line is not very convenient, but no
one did not make work exclusively in it (you're in MS-DOS too
both work?) - writes the file wrapper, and all
becomes very cool! The main thing that has not considered Nemo:
CP / M - is a real OS, and as a consequence, is able to develop
and improve (example - system DOS 4.0 (the pros) is compatible
with CP / M and supports subdirectories). I certainly
understand that iS-DOS was created in his native city for Nemo,
but all well, you can not be because of this so biased.
Reading the various journals and newspapers,
I noticed an interesting trend: Many agree that the OS Spectrum
is needed, but everyone wants to create its own system
(naturally, VERY BEST), which has nothing in common with the
previously existing ones. Since, in their opinion, all the old
system - bullshit. As a rule, these people already have
achieved some success: created several dem (And possibly very
steep), intruh, disketirovali a variety of programs, etc. But,
I dare say if you've written at least 50 superkrutyh demo, it
is not means that you create at least one operating
system (the opposite way, too true). Yet the process of writing
the demos and the OS is slightly different. Many simply do not
understand how difficult to develop an operating system from
scratch. After all, you must fully think through the system,
for example:
1 How it will interact with the programs
external devices and their own
components;
2 How to be organized by an external memory (in the form
files or otherwise);
3 How the system will allocate memory, includ
le extension; ie, how it will manage the PA
myatyu;
4 If the system will manage the files, it will be
whether to use any of the existing
filesystems (ekstentnaya CP / M, FAT, NTFS,
HPFS or another) or will be developed Sauveur
Shannon new file system.
5 What status will be launched programs
we have: serial or parallel processes,
substituted modules or something else.
6 In what form will be a dialogue with users
Telem: as a command line, menu, or the Picts
gram.
In this list I bring the first thing that came to
mind, it has a lot left out! In addition, the program
control external devices (drivers) should
written by a man, at least a little knowledgeable in
hardware (preferably - good). Take for example
keyboard driver. Some may say: "No
could not be easier, and will, of course, wrong. What I have
seen enough in the same demah and email. magazines like crooked
interviewed key! here and unrepaired chatter, zavivisimost
speed replay (Repeat) and the delay before the first repetition
of the clock frequency of CPU and other defects. When Reed's
software keyboard, and he know does not know that there is such
a thing as a "bounce" keys (one must understand the physics of
the phenomenon). Wrote calmly program, they had to work fine,
but only with him. At the other company - is continuous glitch.
Or another example - the procedure for loading the unit with a
tape recorder (the same 1366 or # 0556) how many people
understand thoroughly ee? A because it was the most simple
examples, but there is still extended memory (also there is not
so simple as it may shown), mouse, disks (it is not very
difficult) other devices ... The device driver should be the
absolutely correct no matter from which, as it was his duty -
that's why it is written. Leave podprogrammki, anyhow, if only
work is not difficult. Modules that work well not only on the
machine of the author and do in any circumstances, create a
much more complicated, but still, and they must occupy as
little memory and run as fast as possible.
To develop and implement a new operating system can
leave year 2-3, not counting time spent on
testing, error correction, etc. In addition,
a completely new system, there will be no assemblers
no debugger, no programming language of high
level - nothing at all. The question is, who and why
Such a system is needed, whether it is 10 times steeper than
MSDOS, Windows NT or AmigaOS?
For example, when creating MS-DOS, the authors do not
steel puzzle, but simply took as a basis for CP / M
and improve it. Almost all software from the CP / M was easily
moved to a new OS (was even a special utility that allows you
to translate the source code i8080 assembler code for a
processor i8086). New systems for an 8-bit computers, which
appeared after the establishment of CP / M, as a rule, have
been with it compatible. That is, the system is a CP / M +
"something else" at the discretion of the developer. Because
creating a compatible system, not need to worry about the
underlying software, as it already created: there is a steep
and assemblers, and debuggers, and Languages Vysk level.
Thus, to create a completely new system for an 8-bit computer
that is not compatible with CP / M, totally meaningless.
There is one very important point. Case
that absolutely all of the programs for the ZX-Spectrum
were created, given that the OS on your computer
no. From this, in particular, that appears
any OS, it run the program for the Spectrum
will not (remember iS-DOS). All prog for ZX written on "naked"
computer, using all available memory. The program is running
any OS, in some way limited: they using only the available
memory, to perform certain actions cause the operating system,
after completion of the work through to the OS, but do not
reset memory, etc. Thus, the conclusion suggests itself:
Spectrum and any operating system are incompatible! The
situation would seem hopeless, but still I see solution.
Let's start with the fact that the interface TR-DOS - it is
non-standard device, it does not support any
one western Spectrum emulator for the PC, although supported by
virtually the entire periphery, ever existed on the ZX.
Standard is the same as It is strange - the tape recorder, or
rather, in emulators these are images of tapes - tap-files.
These files are "understood" any emulator, in addition, it at
any time you can write on this tape and upload to the This
Spectrum ... That is to say, the first time, not in favor of
TR-DOS.
It's no secret that the programs normally transferred from
the tape in TR-DOS, there is little, each can find at least a
little, but a glitch (that blocks marred, the picture, then use
a different disc does not want to boot, it does not
"understand" one-sided disk drive, then upload the disk does
not work). A program on the tape is quite normal to work,
without no problem ... Not only does the West program
come up all the broken, when moving to TR-DOS are
once more maimed. It is not often that the program is "purely"
moved - now in one problem or the other. And this is the second
time. Thus, in the long run, you can opt out of the interface
TR-DOS, returning "back to the tape" - but at a new level!
