ZX Club #05 29 октября 1997

Железо

Iron - On Covox'ah, General Sound'e and Sound Drive 2.

               What an idea!


   Essentially topic was opened in the fourth
room "ZX-club" in Article V. Mayatsky "More
just about COVOX ".'s name and concept headings
came later. Defining the idea rather
simple: Enough talk, is not it time
thing to do ...


   Having read and heard plenty of breathtaking ideas of 
computer hardware in general, you can fall into pessimism and 
with distaste an eye on your Speccy, sorry about the lack of 
money or that live far from the places where these same ideas 
slowly, gradually implemented. Then, of course: why do COVOX, 
when in St. Petersburg this topic was closed and going to 
overwhelm Russia General Sound. But we have something you do 
not live in St. Pete! 


   You can not delay the case in the long
box, with minimal cost, to test
something from the "closed" to those here and now!
Easily, in terms alien theoretical calculations, the move to 
reject the simple things. Much harder (and much nicer) to 
perform an experiment: roll up their sleeves, very simple thing 
to do. Perhaps this thing turns out to be not so trivial, but 
the result of actions surpass forecasts ... Argue is preferable 
to complete on a reason: experiencing your own!



   Some of the topics relevant to Barnaul (not only) users:

1. Sound: covox, sound drive (see "ZX For
   mat ", 6).
2. Modem connection for ZX Spectrum - let

   and simple, but the last "field research
   pytaniya.
3. Peripherals:

   hard disk, keyboard, IBM.
4. Memory expansion.


   It is desirable not only to gather and experience, but also 
to document their research: overview (which is available on 
this topic in the press), report (charts, tables, descriptive 
text), and practical advice. 


   If you are ready to provide services to upgrade the 
Spectrum, or are looking for partners to test the modem, or, 
conversely, need a qualified professional assistance for 
hardware, .. Serve deployed (To the extent you have no limits) 
ads. 


   And finally: the conceptual or theoretical articles will 
also find its place in section.



                *


(C) PREDATOR


       The main drawback covox'ov - is
that they can not operate without the support of the processor. 
In general, this reduces to not all his benefits. Even if the 
CPU spends all his time to the ejection of bytes, and then the 
sound is not enough quality. I mean the inability of 
professional work with audio on computers Spectrum. Available 
at 128th and more powerful machines, three-channel 
FM-synthesizer (ie, music by coprocessor AY) clearly does not 
satisfy the demands of music-maker'ov. Recently, a new device 
for playing digital music without the computer's CPU - this 
General Sound. Alas, despite all its possibilities, there are 
also some disadvantages. Some of them are added the already 
high (as Spectrum's standards) price. 


       Realizing some time that
covox really promising device, I thought about General Sound. A 
small digression: covox not promising device because Z80 is 
clearly not pull it. Previously it was assumed that system 
performance will be increased, and along with it, it will be 
possible really support covox, but reworking the entire fleet 
of vehicles is not possible, as development, and acquisition of 
user new car.



       So, first question was
reducing the price of General Sound. Alas, there is almost no 
hope, because the cost of GS (215 t.r) close to the cost of the 
product. 


       Price Sound Drive 2 (since our device will be called) 
will of course be less than the price GS, but not as much as

I would like. But the hardware has surpassed SD2
GS. The most important difference - the greater the amount of
Memory: 1 Megabayt (on GS - max 0.5 mb).
SD2 will be software compatible with the GS, so
that buying SD, you buy yourself SD and more
GS. Nothing will be lost. Giblets SD
will be quite different. In particular, we have no idea about 
the internal schema GS, but for program is not important - 
Ports and Commands will be the same.



       Separately, about formats. Will support the team format 
*. STM and, most total, *. MOD. By the way, the board will be 
installed capacity of 2.4 kb ROM with bootloader OS Sound 
Drive. This again will reduce price and give you the 
flexibility to change players and fix bugs without pereshivki 
ROM. 


       Alas, it is so far only in
Our thoughts and something on paper, but there
reason to believe that the case will be brought to an end. 
After a month and a half exactly scheme will be ready, perhaps 
- the loader. Time of start of production is not conjecture. 
Circuits and firmware ROMs will be available to enthusiasts and 
could zhelezyachniki assemble the device.



       For those who are already going to buy
General Sound can say: if you wait another two or three months, 
you will be able to buy a more powerful device at a

low price. Yes, and software that supports
GS (and SD) will be more.


       In describing the GS has been said that
the sound quality will be closer to "Amiga". A "Amiga" quality 
- as in Audio CD! With a part of its Spectrum SD, you

can really do sound.
By the way, IBM'ovskih sound blasterah is
shestnadtsatibitny only one channel, while
SD - four chetyrnadtsatibitnyh! Plus a full hardware 
independence. The IBM PC, of ​​course, some sound cards

equal-power SD, but here the price they
from $ 200 and above. So it is now, and we
something to be proud.



         Technical Information:

              SOUND DRIVE 2

CPU: Z80H/12mhz
ROM: 2-4 kb with OS-loader
RAM8: 1024 kb (SIMM)
INT: 44.2 khz (CD'shnoe sound quality!)
Channel 8 bit + 6 bit volume control: 4
Outside i / o ports: as General Sound.
Inside i / o ports: as Sound Drive 2!