On-Line #17 31 декабря 1995

IS-DOS     Программирование

Page sysop - "Rise of the dashing, landing ... hare." (About the system IS-DOS).

         iS-DOS: RISE dashing, LANDING ... Zaitsev?
                   OR
        2:1 in favor TECHNOLOGY RESEARCH.



   In autumn 1992 at the software market
ZX-Spectrum compatible computers, a new promising operating 
system iS-DOS, created by the Peter ISKRA-SOFT and widely 
publicized in the pages of ZX-Review in 1993-94.



   Having read about the new, hitherto unseen opportunities, 
the owners of the Spectrum of all stripes and colors rushed to 
search for and buy up all the available drives with this 
system, the benefit of, at the time, system developers have 
worked on the shock fruitful field of fleet replenishment 
programs and systems for her, promising us a new level and 
style of programming and megabytes surprising matobespecheniya. 
Built audacious assumption that maximum of one year the main 
operating system for the Speccy - old TR-DOS relinquish its 
seat on a newborn daze "Sparks" and will be little more than a 
handmaiden of the new "boards". 


   However, the time judged differently from sparks and flames 
did not was destined to ignite. Now, after several years,

TR-DOS, not only is not going to capitulate, but not without 
the direct participation of our renowned and lesser-known 
coders and Hacker, is experiencing a rebirth, drawing on their 
toward its most ardent fans iS-DOS, koim and your humble 
servant. Therefore, I find it hard to write notes on this 
topic, especially under such a title, but still I will try to 
be objective and fair to consider the advantages and 
disadvantages of both systems without raising slander to any of 
them. 


   So, thanks to the efforts of "ISKRASOFTa and SLOTa iS-DOS 
slid from the crest of popularity and demand for it is not just 
fallen, and disappeared altogether. Now no one asks the sellers 
in the market or that iS-DOS disk. It is worth paying attention 
to the fact that even in "Inforkome" no more now a tenth of

that "iS-DOS plenty" that was, say, six months ago. Apparently,
M. Helloween still was not right to call the N 1 ZX-Review for 
1994 year to transfer the software on the iS-DOS and guidance

order on the disks. It seems that time has passed iS-DOS and 
its fast rise may result in the best case, an emergency landing.



   What is the cause of this situation? In principle, the 
answer to This question does not require detailed explanations, 
but all the same try to answer it. 


   I beg your pardon aces programming for what will set out 
basic things. But the ON-LINE daily for all therefore, I write 
for everyone. Also, excuse me, and for any inaccuracies and 
errors. Anyway, I'll be glad to any criticism, comments and 
suggestions. 


   As is known, iS-DOS performance on machines with volumes of 
RAM ranging from 48 kilobytes, and occupies the upper memory 
addresses. Depending on the configuration of the address of the 
nucleus can change. When established five levels of the nucleus 
it is equal to 50,400 (# C4E0). Thus, these five levels take 
about 15 kilobytes. 


   Immediately prior to the core area is reserved for drivers 
and resident problem. More below are currently open channels, 
ie continuous memory locations, used by the system and the user 
program for temporary storage or transmission of the variables 
and parameters. 


   Going down even lower from RAMTOP we discover another 
interesting and no small chunk of memory, namely the cache 
(cache) or virtual disk. In essence, it is easily available a 
copy of those disk sectors are accessed most frequently.

The cache size is given in blocks of 260 bytes. Minimum size
it is 6 blocks, ie 1560 bytes. However, in this case
Work iS-DOS disk slows down terribly and will remind
hellish flour, the more that turn to drive iS-DOS is very fond 
of. By default, this value is assumed to be 29 units (7540 
bytes). All those who wonder why it was done this way and not 
otherwise and where did it exist values ​​a virtual disk 
volume, I refer to literature listed at the end. 


   And finally, the region with the address 23900 (# 5D5C) 
before the cache available to the user. Realistically, you can 
count on the 6,188 bytes of memory, ie, a little over 6 kb. I 
confess I was a bit discouraged, when, trying to write 
something in assembler under iS-DOS, was to poke his nose in 
these same 6 K. The feeling, I confess, as in a coffin - a 
narrow, cramped and no freedom of movement.



   Of course, the skill in terms the size of the cache can 
bypass this problem and increase the amount of free memory 
space. However, with this approach you will still lose, because 
the memory of you so and so is not enough, and podzagruzki from 
disk will take longer time than usual, ie when the size of the 
virtual disk specified by default. 


   As you can see, you'll have to write a bunch of overlay 
modules for its creation and, possibly, their own level of the 
nucleus. In the Programmer's Guide to the iS-DOS environment, 
you and advise: Write your own level, plug it in and appeal to 
it as needed. Oh, and do not forget to tell the system restarts 
your table level, but nothing of this scheme will not work. 
Break all the available maximum (it is the same at least) the 
literature on iS-DOS, I have not found any indication of how 
the same still pass this ill-fated system table. I had to spend 
time hacking a couple of databases (imagine what it task - 
opening programs under iS-DOS?) and find out eventually that 
the report, it appears, do not need anything. Simply place the 
table directly in front of their standard codes and it's done.



   The reader who is even slightly familiar with the 
possibilities of iS-DOS and the basics of programming in it, 
can reproach me that there are a couple ways to increase 
available memory. For example, remove the top two levels of the 
nucleus - 3 and 4 (win.sys and shell.sys respectively). I 
agree, of course you can, but as a result lost the opportunity 
to work with the panels and windows and in addition there is a 
necessity whenever the output from your program reboot the 
system kernel in memory, which is not so nice. 


   On windowing system, wired into the code iS-DOS, you can say 
a few more. And have to begin with, it's not so bad have at 
hand a ready window interface, with a rather correctly 
implemented the menu system. But, again, the same amount of 
memory imposes some restrictions on the use of this interface. 
Firstly, any size box you would not have opened, the image 
under the window is not saved, because the extra memory does 
not exist even in the 128th car. Secondly, the cursor control 
on the menu is set once and for all and no changes are subject 
to. Third, the menu itself can only be vertical, but for the 
realization of the horizontal menu, located along the screen, 
you will in any case have to write their procedures, ruthlessly 
razbazarivaya precious bytes of memory. 


   So, using the memory iS-DOS, we broadly understood. Let us 
now see how this system will be disk space, and then proceed to 
examine existing software. 


   Dear reader, take any iS-DOS disk and carefully
look at the contents of its main directory (I mean SHELL,
SERVICE, UTIL, etc.). If you are not happy owner of a 
128-second computer (though this may apply to the happy owners 
of them), you will notice that 1 / 3 of the disk occupied by 
the files needed for proper system operation. The remaining 
60-70% of disk space is given to the needs of the user. Thus, 
out of 800 KB for iS-DOS disk, you can use Only 500-600 KB. 
Besides it, the more key system files, must be present at any 
iS-DOS disk, excluding only archive. Wait, you say, but then 
the MS-DOS keeps on disk system files and any claims to 
IskraSoftu in this regard There should be no. Yes, your true, 
but the ZX-Spectrum is you do not IBM and even a 5-megabyte 
hard drive, it does not have, so the rational use of disk space 
on the agenda can not be removed. 


   A few words about the format of the disc in the iS-DOS. In 
contrast to TR-DOS This system creates when you format on the 
track instead of 16 sectors of 256 bytes, and the 5 sectors of 
1024 bytes. This format allowed the developers of the system 
not only increase the disk capacity of up to 800 Kb, but also 
make the drive autostart when performing not only standard 
startup command TR-DOS RUN, but such as LIST or CAT. The result 
of implementing such a solution was a complete incompatibility 
of iS-DOS and TR-DOS disks. To transfer a file from one system 
to another have to spend a certain amount of time to copy 
files, convert them (if necessary) appropriate format, etc. And 
then we wonder why iS-DOS was slow even more than before. In 
the end it turns out that program to transfer files and 
to_tr.com from_tr.com ruthlessly cut back cache.



   But something is going on at the front of the software for
iS-DOS? For more than three years of existence of the system 
for her, but Forth and assembler, was not created by any 
language, any programming system. A iS-DOS BASIC? " You ask. 
But, sorry, and supports the TR-DOS BASIC, and more democratic 
apply to the coder and to the hacker. Try iS-BASICe create 
anything, though, would be to calculate your exchange rate / 
graduation project at the college or institute. Where do you 
get to, for example, a data file, if memory space is not enough 
for even the most program, not to mention the fact that the 
data files as such in iS-BASICe does not exist? About Forte and 
other packages, we will talk later, and now turn to perhaps the 
only decent and well-written iS-DOS program - the text editor. 


   I have not sinned against the truth when I say that the 
iS-DOS EDITOR can rightly be called a professional text editor. 
If not, the system under which the editor was written, he up-to 
perfect competition ZX-WORDu, Fwordu, SpeccyWrite and EDITORu, 
not to mention the TLW. It is possible that he was-would 
de-facto standard for text editor to create text and messages, 
documents and articles. Compared with others, I have mentioned 
above, editors, iS-DOS EDITOR has powerful opportunities for 
formatting, content search and replace, print text. Want to go 
to any line number in the text? Please! Want to insert into the 
text contents of another file? Please! And how do you like 
"rubber" pseudographics? Why suffer in the search key, which 
hung the symbol of the left upper corner of the frame when the 
cursor keys can be easily draw the entire frame, with either 
double or single, and if necessary at all to erase it. Yes, and 
the volume text, there are no restrictions, because the text is 
almost entirely located on disk and in memory is stored only 
piece of his work. Of course, this slows down the editor, but 
not so much to get irritated and begin to help your finger to 
spin the drive. The advantages of the editor should be 
attributed also to work in alternative encoding.



   Speaking of the iS-DOS EDITORe impossible not to mention 
other programs for word processing, such as: text viewer 
(tv.com) and archivers texts (arctext.com, unarc.com, 
arcview.com). TV.COM, for example, has such a wonderful option 
of either viewing the text on the screen without pressing any 
keys. That is, you sit in front of the screen on which upward 
or downward smoothly glide lines. Well, scrolling speed You can 
change to your liking, fear and risk.



   Let us briefly consider other software packages for iS-DOS 
and begin, perhaps with another editor - graphic. 


   1. GRAPHIC EDITOR PICASSO. As soon as we are talking about
this editor, so let's just its author elementary
grammatical errors, which are full of menus and documentation, 
the more that it is not in them. So is go around with their 
attention issues related to the "Ping" the package even

128-x machines. It's not that. The question posed to the 
developer somewhat differently: How is it to make the program 
almost completely analogous to "ARTIST II" and use its 
interface, so more, reducing the original features to a 
minimum, while quietly, you can draw any picture using both

ArtStudio, and Artist, and then, using the standard, and I 
emphasize the standard of iS-DOS transfer this file to it? Of 
course, I could argue, for Picasso allows you to create 
Pictures larger than the standard screen size. So what? After 
this is not the main criterion for selection of a graphical 
editor, the more so that the screen for users as iS-DOS, and 
TR-DOS is one and the same-size, but the printer is not true of 
everything. 


   2. iS-DOS ASSEMBLER. In general, it is the same old kind
Gens, complete with dozens of new guidelines, plus the 
opportunity to cook a program from several object modules. 


   And now imagine the old inveterate fan
TASMa, decided to expand the boundaries of their creativity 
beyond the TR-DOS and tailor them to the offspring "Iskrasoft. 
But he was not used wait for the result of assembling ten 
minutes! Therefore, he soon sneeze at this thing and reformat 
your drive with the iS-DOS Assembler for TR-DOS no matter what. 
I do not want to thicken and already bleak, but for programming 
(specify - serious programming) in the iS-DOS, if we close our 
eyes to all its impartiality, requires a minimum of debugger 
type MONS, not to mention more. Such a debugger iS-DOS does not 
have yet far.



   3. DATABASE DATALOG. Perhaps, along with a text editor,
this is the only iS-DOS system, which could be up-
competition of this kind matobespecheniyu a TR-DOS. Let wishing 
to become familiar with this database and see if they need it 
or not ... Although, like everything written by iS-DOS, Datalog 
can scare you with its inhibition. That the same concerns 
TR-DOS, then I personally know two more or less worthy of the 
database, working with her. This, of course, Masterfile, and 
BK-Cardfile, is channeled through the "Inforkoma. 


   4. FORTH. The very idea of ​​implementing this language to 
iS-DOS I do not understand because it is "a language for the 
elite," ie, not everyone needs it and not everyone will be able 
to write. Especially, that the implementation itself is buggy. 
What is the point of having to Speccy another compiler that 
without the presence of memory the compiler itself will not 
trigger any of your program. And it's - with total deficiency 
of free memory. 


   5. Spreadsheets and electronic note book. Here
All the same, namely, low speed, minimum service and minimum 
interface with the user, although the internal iS-DOS tools 
allow you to create a fairly powerful window interface. In 
general, these designs look pretty pathetic in comparison with 
similar systems written for TR-DOS. 


   Such iS-DOS systems such as Lotus or English-Russian 
Dictionary I can not say anything because I was not able to 
meet them. On the other hand with respect to the dictionary, I 
note that it is not so bad realized I mentioned above, file 
cabinet BK-Cardfile. Of the reasons the developers of the 
system to write programs such as warehouse and material values, 
Shop I think we are not talking. Of course, it is nice to know 
that our good old Speccy able to perform the same tasks, over

that up a sweat beating IBM. But on the other hand, why should 
write a program whose future was originally on landfill or a 
good memory programmers, because even in the most run-down 
office of computing will find in the worst case, adding 
machine, "Felix-M or a calculator Citizen, but you will not see 
the proud letters ZX ... 


   As you can see, most of the problems associated with the 
iS-DOS, runs into one and the same-namely, the disastrous lack 
of memory when writing their own programs. Of course, the 
average user or player it's not necessary, however, as she 
iS-DOS. A Here coder or a hacker would have to pretty sweat 
before he make sure that it does not work. And the best way out

the situation will be spit on iS-DOS and, like the prodigal son 
to return to the bosom of the good old TR-DOS. The only ones 
who can still be a useful product IskraSofta, so it's "writers" 
who spend most of the computing time for the establishment and 
listing of every text. 


   "So the same" - asks the user. - "Do take and
reformat iS-DOS disks under TR-DOS? "No, of course.
All disks do not need to reformat. You can leave some of the
them, for example, basic kit, of course, the disk with the 
editor and working text, database DATALOG. Believe me, they are 
ever more useful to you. But the rest ... The rest - a matter 
of taste and affections of everyone, although again, I note 
that programs running under the TR-DOS cope with their tasks 
better, faster and more efficiently. 


   Why do the same IskraSoft created a new operating system? 
Was it only in order to maximize "IBM-izirovat Spectrum? Or to 
express themselves? Let this question remains open. Better if 
it will answer you, dear readers. Me, it seems that the iS-DOS 
was created in order to write programs under ... iS-DOS. 
Although my opinion may not be fair. What do you think? 



             L & T E R A T U R A



   1. Programming in iS-DOS. Programmer's Guide.
"Iskrasoft", St. Petersburg.; "Slot", Moscow. 1994.

   2. Operating system iS-DOS. User's Guide.
"Iskrasoft", St. Petersburg.; "Slot", Moscow. 1993.

   3. Leontiev, A. Demidov. Short course of history iS-DOS.
Revue ZX-N1-1994, p. 7.

   4. M. Golovin. Adaptation of gaming software systems to the 
TR-DOS professional system iS-DOS. Tam, p. 10.


   5. Visiting the company's "SLOT" (interview). ZX-Forum 1, p. 
38. 

   6. M. Golovin. Programming experience in the operating system
iS-DOS. Example of writing a printer driver. Tam, p. 47.

   7. I. Forest. iS-DOS (. exe - files). ZX-Revue N5-1995
p. 13.

   8. What exactly is iS-DOS? ZX-Revue N3-1994, p. 57.

   9. iS-DOS. ZX-Revue, a collection of over 1993, p. 190.


                    Hallowe'en Research Inc
                        24 dec 95