Programming - some issues of creating file shells on SPECCY and a review of SPECTRUM's DOS's.

Deja Vu #0A
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(C) 2000 KAPsoft
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            BOOTING

   In my article I want to discuss some
basic questions about creating file shells on
SPECCY, and consider SPECTRUM's DO-
S's, in general.
   So let's begin...

 PART I

 CATALOG SYSTEM IN TR-DOS

   Everyone knows the convenience of catalog systems.
Everyone knows that TR-DOS is not a catalogue.
system. Many programmers (and, indeed,
Now, everyone who seriously works for SPECT-
RUM) know what torture this is...
   There is a way out!!!
   I suggest creating a catalog system
not at the DOS level (this is impossible), but at
file shell level.
   Let me explain in more detail. The disk contains
a file that contains information about the
catalogs of this disk. File Commander
reads this file and gives it to the user
directory structure of the files on this disk.
   Thus, the disk structure is
but does not change - the same 128 files in one
catalogue. But for the user they will be
stuffed into small directory folders.
   Next I suggestfile-description standard
catalogues.

  - Maximum number of files  128
 - Maximum number of directories  32
 - Directory name length  6
 - Number of files in the directory  up to 128
 - Subdirectories yes

The length of the descriptor file is 2 sectors.
 Descriptor file name - director.C

 1 sector:
 32 entries of 8 bytes:

                  0-5  directory name
                    6  start of information
                        about files and sub-
                        catalogs in the 2nd
                        sector.
                    7  number of files andsubdirectories in
                        this directory.
 2nd sector:
 N records of M bytes each ( N -
                   number of existing ca-
                   talogs; M - quantity
                   files in each directory
                   loge. ):

                  0-M1 file numbers in
                        1st noun catalo-
                        ge.
                  0-M2 file numbers in
                        2nd noun catalo-
                        ge.
                  etc.

  File numbers: 0-127 - files from TR-
                           DOS
                           catalogue.
                 128-159 - subdirectories.
         128  - first
         129  - second
              . . .
         159  - thirty-second

   Hope someone understood my idea.

   In principle, this could be the basis for
finish the description of the idea, but I want to give
one algorithm for working with a description file
lem.

 * PUSHING THE FILE INTO THE DIRECTORY *

  Input: A-file number (subdirectory)
        W-which directory (0-31)

 1.Look at sector 1: byte (a*8)=0?
 Yes - exit (error - directory not
 exists)
 2. Let C=(a*8+6)
┌─3.Cycle I=0 to 31
│ 4. If (I*8+6)>C, then (I*8+7)=(I*8+7)+1
└─5.Next I
 6.Look at sector 2: shift the bytes by
 starting from C to 254 to one.
 That is. (C) = (C+1)
 (С+1)=(С+2)
 . . .
 (254)=(255)
 7. Let (C)=A
 8. Upload a new catalog:
 SAVE "director" CODE

   And one more thing. How to determine which
Which files (directories) are located in the main
catalogue? Very simple - all files and ca-
tags whose numbers are missing in 2
sector are located in the main directory. Name
main directory - disk name.

   I also want to say that such a system
needed not for game discs, but for work
sneeze It is also desirable that it be used
was in powerful file shells that
have the ability to work with overlays.

   Consider this article as an establishment
standard for this type of system. I ho-
I think that the creators of ...-COMMANDER's will re-
used my ideas and created a convenient
a file shell for working people.
   As a last resort, I myself, when they get there
hands, I’ll make something like this COMMANDER (I hope that
this will happen somewhere in the middle of 2001
yes).


 PART II

 DOS's on ZX - O-O-H MY GOD...

   So what do we use...

   TR-DOS (good old fairy tale)...

Advantages:

   1. Perhaps the most important advantage
of this system is that it is built into
Computer ROM. No problems with loading
which system -no matter what happens, she will not
where it will not disappear from the ROM.
   2. Its second and last advantage
is HUGE software support.
All systems and games are written only for DR-
-DOS.

   Disadvantages:

   1. Lack of directory structure.
   2. All files are sequential, written
in a row even on faulty areas.
   3. No support for additional memory
and RAM disk.
   4. Illiterately written.
   5. There is no way to change DOS (here are the
advantages of the fact that it is in ROM).
   6. ...

   Thus, how well someone wrote
lard in Review, TR-DOS - accelerated vari-
ant tape recorder.

   IS-DOS

   Dignity:

   1. This was a successful attempt to write in
SPECTRUM is a real operating system.
   2. Directory structure, support for up to
additionalmemory and everything that would not be
lo at TR-DOS.
   3. Quite a lot of software
readings.

   Disadvantages:

   1. The system was focused on popular
new at that time NORTON COMMANDER and was
simply copied from him. But commander
That's why he's a commander, he can be thrown out
and install another, more modern one
ny. Try to separate IS-DOS from SHELL.
There's no way it's going to work.
   2. Lack of multi-windows. This, in about-
in some ways, not a big drawback, but I...
then I found myself in a situation when I needed
was to watch something without looking up
EDIT. I remember I swore a lot :).
   3. The system is more compatible with MS-DOS,
than with TR-DOS, which, of course, is not encouraging.
   4. From the very beginning IS-DOS was oriented
was a business person, but making money
Only a few can make money on SPECTRUM:(.

   For these and some other reasons, in
in general, a good DOS did not become standard
vol. Currently in IS-DOS only
write documents (EDIT - the best program
for IS-DOS)...

   Well, that's all for today. So already on-
wrote more than two hundred lines.Whoever disagrees with me - with pleasure
We'll talk.
   Who is interested in the first part of my
articles - write.
  I will answer everyone.

 612831  Kirov region.
 V-Kama district.
 pos. Rudnichny,
 st. Ordzhonikidze,
 building 33, apt. 48,
 Kiselev Alexander Petrovich
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