Plutonium #19 20 августа 2001

Софт

Soft - X-DOS on the development plans of the new opertsionnoy system for the Spectrum.

                           ·



 (C) Boh / Image Crew ...


     Projects for the future ... Ceychas we have here as it 
simply turnover rate is, then there is no any plans not to 
build, and just live.


     Unless specifically about X-Dos, then a lot of things were
invented, and many started. But everything has to make me one,
and too many things to me hanging (and not only on the Speccy)
so almost nothing is finalized. And then there just was not ..

     - Database, which incidentally is already working well
visual structure editor, the case for brauzom costs.

     - XMetaFile, part of an ideology whose presence in
muz.pleere X-MetaPlayer, namely, there is a format for XM,
combining absolutely any music formats.

     - And the most important was the plan, it's X-Dos 2.0 ... 
For which have already been written memory managers and the 
problems (nevytesnyayuschaya multitasking).



     Now, new programs appear when I have someone
utility will ask some to write, or, well, like a game
Life. For something more to me one time is not enough, and
nobody else really not.


     And what do you mean by "how people perceive"? Those who
delving into it, quite happy and pleased to accept something
new. C such that you download, run run look:) Also
I wrote to bend only one I know of people, but now he
probably already forgotten it ...


     With the advent of global zxnet though I rassprostranil
kernel + some program (of course not all), but the response for 
some reason sooo small. I'm certainly not the sea of ​​letters 
and waited, but in fact more interested in only you let another 
one. 


     Now tell on specific ... At this time - about
universal container X-Metafile ..


  Well, I tell ...

     X-MetaFile - it files with the usual extension XM. (Not
confused with the music modules on the PC!)

     This format has been coined specifically for the 
universality store any data perfectly, and also with 
information about them!


     Opisenie give the current version of the format, although 
IMHO it is needed still in development, because some things are 
missing. 

     Must first introduce a concept of the atom. Atom - is
4-character text identifier of the file's contents. The fact
which the atoms are already specified later, but give you an 
example: the atom "ASM0" means that it contains music format 
ASM 0.XX! 

     Thus, each xm-file has a 128-byte header
directly followed by the data come from. Here is a description 
of the title (Pascal-style):


 Atom: array [1 .. 4] of Char;
 Len: Word; {full size}
 Reserv: array [1 .. 11] of Byte; {11} bytes reserve
 Name: String [50], {Name}
 Author: String [50];} {author
 Date: String [10] {Date}


     Line also in the style of Pascal (ksdos with such up and 
running), where the first byte - length of string, and the 
number in [] - Max length.  For those who do not understand, 
here's an analogy to the ASME: 

 ATOM DB "ASM0"
 LEN DW (length)
 RESERV DS 11
 NAME DS 51
 AUTHOR DS 51
 DATE DS 11
 In total 128 bytes.


     Starting from the atom, the program seeks overlay Player 
Player, which registered the atom as his own. Thus,

identification of the file is very simple. So far recorded only
music formats, here is a list of atoms, and the contents of 
xm-file Atoms:

 (All without the players)

 ASM0 module from ASC Sound Master v 0.XX
 ASM1 module from ASC Sound Master v 1.XX
 PT2X module of Pro Tracker v 2.X
 PT24 module of Pro Tracker v 2.4
 PT3X module of Pro Tracker v 3.X
 PSC1 model from Pro Sound Creator v 1.XX

       the first two bytes of data contain an updated version 
number 

       eg # 01 # 07 - PSC 1.07

       then the music itself
 ST module from the Sound Tracker
 STP module from the Sound Tracker Pro


     It is still all but to support the new format, we need only
overlay write.

     Now a bit about the program X-MetaPlayer. This overlay
Player X-MetaFile, but is able to understand and
original (non-XM-header) files from the above
muz.redaktorov. Done it this way. Overlays are separated
into three types: input, player and visualisation. On the order 
of each type:


     input - an overlay that recognizes the file type and 
automatically converting it into X-Meta format (with header)


     player - player-specific or more
atoms (eg ASM0 ASM1 and implemented in a single overlay)

     visualisation - rendering the music:) Kanalchiki,
indicators, frequency analysis, or simply any effect in
the lower third of the screen.

     When you select a file in a directory (or as a parameter in
kom.stroke) algorithm is as follows:

     - Caused by the order of all the input-overlays, while some
of them will say that this file it. After that, it is 
considered that in Memory is a ready-xm-file.


     - Checked all the player-overlays to support the desired
atom. If a player is found, start playing, otherwise
announce that you want is not the player.

     That's all, because everything is very simple. And since 
all the overlays on ramdiske, search speed acceptable.


     On the format overlays and their functions while I will 
not tell, if necessary, then the next time.


     Let me just say that they were thought to extend the 
header to 256 bytes. Thus simplifying the loading and the rest.



                                          To be continued ...

                    Ekaterinburg city 2001.