Adventurer #10 30 сентября 1999

История

Interface - a success story Apple Macintosh.

     (C), Mikhail Smirnov (CLEAR) Rybinsk


                 PART II

               (Continued)


     Now we go again about the sound and
not only that. (Brad as nonsense - nothing special).


     Ideal computers and there never
there will be no glitches are everywhere, with the only
difference is that some of their more than
others. (Gluck - code, or hardware
nedoglyad developers.)

     Constant disputes adherents Amiga and
PC to read, of course, very interesting, but
world of computers is much wider, so I
talk about almost unknown in Russia and
CIS computer, ranked second in the
the world in prevalence after the PC -
Apple Macintosh. (Apple has managed to
80 score Macs entire system of "popular" education dollars - 
from kindergartens to universities). I hasten to note - I did 
not call home to buy the Mac, so as it will be very irrational 
(in CIS).


     The history of creating the first computer
Apple's a bit like a story
Amiga is a story of ups and downs, not
cease, and to this day.


     Everything started with the "garage", two other
Steve Jobs and Steve Wozniak, learned of the output
in light of a new microprocessor firms
Motorola, decided to create a computer game on one card (up to 
this point they both were fascinated by electronics,

In addition Wozniak worked in the firm
"Hewlett Packard", and Jobs in the firm
"Atari"). They planned to distribute it among the members of 
the computer club "Home Brew Computer Club", they have also 
previously organized. On the development took about six months, 
ready to board was then placed in a wooden cabinet. Computer 
show the newly attributed to the owner of the local computer 
store, who was a member of the club. He ultimately offer Steve 
the deal: they make 50 per month computers, and he pays them in 
cash on fact.


     Then it's time to come up with the name of his firm. 
Charter sort out intricate variations Jobs jokingly suggested 
"apple" (apple). Quite unexpectedly, a word like both, and it 
they stopped. April 1, 1976, they established firm Apple.


     Evenings and weekends Stiva continued to work on your 
order. Exactly on time, they put 50 computers at the price of 
an Apple 666 dollars 66 cents. Satanic number

caused a firestorm of local communities, members and customers 
- the price had to change.


     Cases began to go uphill. Millionaire
Markulla invested in the company U.S. $ 250,000 and began to do 
business, providing Wozniak and Jobs freedom of creativity. The 
company's turnover in a short time was millions of dollars, and 
employs hundreds of workers and employees. 

     In 1979 (3 years), the situation
began to deteriorate - the computer market
PC came from the "Big Blue"
(IBM). We had to do something.
Jobs together a team of talented engineers (some were from the 
"Xerox") and began work on a project called

"Mac." This project was completely
independent of the computers under the name
Apple (which continued to be issued).
Jobs did not suit IBM - this configuration, operating system, 
PRO-DOS and other things. According to his plan to a new 
computer, everything had to be built otherwise.


     At that time, Apple was carried out three projects: 
Macintosh, Golden Delicious and Pippin - all named for the 
varieties of apples. The name "Macintosh" picked up engineer 
Jef Raskin, who, like many Americans suffered spelling - grade

Apples was written "Mcintosh". But the bug fix did not.

     That is such a curiosity owed his
name of a newborn computer that uses no text, and graphical 
user interface. It was a real revolution in computer technology.


     The official birth year, "McIntosh"
- 1984 th. Firstborn name or Macintosh XL
Lisa. He had 3, 5 "floppy drive, 9" monochrome monitor, mouse, 
and a very modest current concepts of memory.


     Since then, "Poppy" fully grown, grown up and become
indispensable artists, publishers, and all those who are not so
it is important to delve into your computer
engaged in it my favorite thing.

     To date, Macintosh is the only real alternative to the PC. 
With the release of "Windows 95" PC users are hoping that their 
heartthrob will be equivalent to the Mac. What in really?


     In the world of IBM PC - compatible computer computers 
themselves and their software is usually developed different 
firms. Therefore, comparing with PC Windows and Macs, compare 
features installed on them operating systems. However, since

used the whole complex - the computer and
OS, such an approach is not quite right. When buying a Mac user 
receives an integrated system in which software is closely 
associated with hardware. Clearly, in the case the PC is not 
so. Recently I read in Computerworld: "Many of the features

InDesing (new publishing program)
were shown how to
Macintosh, and in Windows. However, in
Progress Windows - version of the system error message is a 
memory that the audience responded with laughter and applause. "


     A friend of mine recently visited
Switzerland, where he talked with the local network 
administrator in some school (50 and 9, Mac PC), so he 
complained that he had to tinker mainly pisyukami and to Macs, 
he almost did not fits.


     The main advantages of Macs
as they were, and remain easy to use, the possibility of 
multimedia applications, the lack of compatibility problems. 

     Despite the significant steps
Microsoft's "ochelovechevaniyu" interface
new operating systems, Apple remains
leader in this field. If we are talking about
ease of use of computers in general,
then Apple benefits from the operating system. Given that the 
development graphical user interface (GUI) in the Apple

started long before similar studies for the PC, the company was 
able for it Time to go far in front. McIntosh to

So far easier to use, especially if
we are talking about the integration of computers into a local 
network or configure them. 

     Macs, as long isolated part of the computer business,
today are the most "compatible"
computers. In this area, Apple has made great advances, and 
overcome the gap between Macs and PC. Today, Macs can not

only read and write PC - floppy disk drives CD-ROM, but also to 
perform Dos and Windows application. To this end, various 
Windows - emulators, one of the most last - Virtual PC (fully 
emulates Pentium MMX). In turn, the PC also have a Mac 
emulator. How it works under these emulators - a separate 
conversation, may require a separate article. Briefly what he 
saw himself: Virtual PC on Power Computing 225 MHz (clone Mac, 
Power PC processor 604) emulates Pentium 90 (Frequency 
Processor), video works almost two times slower; on a G3 350 
MHz - Pentium 166 MMX with no brakes. Basilisk on the Pentium 
166 MMX, overclocked to 187 MHz emulates 68020 1 MHz! :) (This 
is not a joke) 

     I do not think that the emulator was written specifically 
for Mac BASIC and an emulator PC assembler (though who knows:)).


     In the early 90's, Apple again
there were problems due to poor management of the company (by 
this time the founders of Company Steve Wozniak and Steve Jobs 
went out of Apple and doing his own projects), anyone who feels 
like she began to prophesy ambulance death and withdrawal from 
the market of personal computers. Apple grabbed the "straw" in 
the idea of ​​creating a RISC processor, the basic concept of 
which were laid in the mid 80's, and together

with IBM and Motorola have released a new processor PowerPC. 
Almost immediately, along with the announcement of the PowerPC 
Apple unveiled a new computer on the basis of their "Power 
Mac". PowerPC processor was in some way

response to Intel 'y on the Pentium MMX, and after
Released Pentium II was presented to PowerPC
G3. These steps, though correct the situation,
but before the crisis was far away.


     In general, the struggle for markets between Apple and
IBM is a struggle not so much between platforms as a whole (if 
we take the technical side, but not marketing), but among the 
processors. Intel, as the leader, stepping on the technological 
and architectural progress, collect all the "bumps, banks,

running track, "wound on the condition and make
not too shabby masterpieces, struggling not for long
forward.

     After leaving in 1971, a landmark
Intel 4004, this trend is seen
the naked eye. Many firms found that the production of 
processors brings good dividends and have rushed to sculpt the 
"stones". Someone walked in the footsteps of Intel, someone 
went his own way, but the majority created their creations (at 
equal - the data bus and frequency) is much better than the 
leader. Example Z80 and 6800 more productive than the i8080.

It was not in the frequency and bit rate, and in
internal architecture of the processor: 6800
had only two general register
(Both can operate simultaneously as batteries), using 3 cycles 
for the read-write when addressing memory. 

     In this race, Motorola, barely kept pace with the leader 
(given only to certain processors): 8080 - 6800, 8086 - 68000, 
80286 - 68020, 80386 - 68030, 80486 - 68040, Pentium - 68060, 
Pentium - Pro PowerPC, Pentium II - PowerPC G3.

About the Pentium III, it is not a new processor (in the usual 
sense, the new processor on the old software on the same 
frequency The results are faster), this Pentium II

with the addition of several new commands for
work with the Internet, and more appropriate to be
had called his type - "Pentium II +". But in
a situation where competitors come on
heels, incomes fall takes a bit
zapudrit people brains (Marketing:)) and
corrected it - the crowd pushes US users outdated Pentium II at
the far shelf, and run to the store to buy
"Modern Pentium III".

     Now for the G3 - a full 64-bit
processor (with Intel Mersed still in draft)
5 pipelines, 2 of them for floating-point data, the L2 cache at 
least 512 KB. 

     In September, appeared G4, and on its
based Power Mac G4, which provides
performance of more than 1 billion floating point operations 
per second (peak performance of the PowerPC G4 reaches 4 
billion in the second). A distinctive feature of the new 
processor is embedded SIMD-module (under named Velocity 
Engine), allowing high speed parallel processing of vector data 
and has additional 162 processor instructions registers and 32 
bit depth of 128 bits. When using a set of tests developed by 
Intel to demonstrate CPU speed Pentium III, PowerPC processor 
G4/500MGts was on average 2, 94 times faster Pentium processor

III/600 MHz. When comparing the performance of the program SETI 
@ Home (the project the search for extraterrestrial 
intelligence) PowerPC G4/500 MHz processed within 6 hours of 
such a wealth of information, which is a Pentium III 600 MHz 
processed within 25 hours. For more information, please visit:

http://www.apple.com/powermac/
processor.html.

     The lag in release processor models Apple neustraivalo in 
order to end with this and was formed an alliance with Motorola

and IBM in the early 90's. Although 68060 was
more productive Pentium 'A marketing ploy Intel' a - refusal to 
use digital system in the designation of its new processors 
nullified all attempts competitor to earn good money from

increase in sales of Apple Macintosh. At the
while the ratio of processors
the desktop was about 1: 10 in
favor of Intel. Fading rate induce sales of Macs Motorola fewer
invest in developing the next generation of processors 680h0. 
Apple, experiencing another crisis, needed a miracle and a 
miracle in the form of alliance has brought not only financial 
investments but also intellectual and technological, 
represented by IBM.


     In 1993 he appeared PowerPC, which has within RISC - 
architecture (reduced instruction set) emulation commands 680h0 
just software, in contrast to Pentium, which is only partially 
RISC - 80h86 hardware emulation commands

(Intel, burdened with compatibility, not
could afford such experiments).
Pentium Pro was already a pure RISC, but for
Compatibility with previous generations
Number of processors crammed with such
logic, that its production has now become almost unprofitable.

     Apple, jumping on the PowerPC,
not particularly think about the consequences, to choose
it was not anything else - "sink or swim." Download 680h0 
worked the brakes, and popular programs had to re-

recompile under PowerPC. New versions of the programs began to 
emerge with two installations for 680h0 and PowerPC 



     The first processors PowerPC (601, 602,
603, 603e) inferior in performance
similar to Intel, and only the PowerPC 604
were able to beat them, with the advantage
was hardly significant.

     Along with the PowerPC 604 was released first samples of a 
64-bit PowerPC processors 620, which has doubled more 
transistors than the 604-th. It was the biggest disappointment 
- superior Pentium Pro was not More than 10%, so in the next 
PowerPC 750 changed the microarchitecture, and obozvali

PowerPC G3 (Generation 3 - CPU
Third generation).


     Simply using a PowerPC G3 at
Macs are not allowed to significantly increase
sale. At this point, Apple's back
(After the failure of "epic" with a computer
"Future" - NeXT) one of the "founding fathers" - Steve Jobs. 
Under his strict guidance Apple has taken the path changes 
design of computers (both external and internal).


     Almost a year ago the world was surprised by the new 
development of Apple - iMac, especially designed for home 
entertainment and Work on the Internet. System unit

iMac 'and is combined with a monitor (candy bar)
and the dimensions of "monitor" from this almost
not increased, body translucent -
shows that under it, no 3, 5-th
drive (seen in the states he no longer needed
- Wherever tkni, around Internet). Since January 1999, iMac 
'and come in packages of five different colors: 


     - Blueberries

     - Lime

     - Strawberries

     - Mandarin

     - Grapes



     Now in more detail (May, 1999
city):


     PowerPC G3 333 MHz Cache 512Kbayt
(Backside L2) system bus 66-MHz cache
Tier 64Kbayt 32Mbayt RAM expandable to 384 MB Memory Bus 64-bit


     Internal hard drive 6Gbayt
CD-ROM 24-x


     2 USB ports for connecting up to 127
peripheral USB devices to each rate of interaction with devices
12Mbps


     Built-in 10/100BASE-T Ethernet Modem 56-K, supporting the 
K56flex standard and V. 90



     Display: - Type of multiple-scan, the tube
shadow mask: 15 ", the size of 0, 28 -
6Mbayt video memory - Refresh
up to 117 Hz

     Video: - Built-chip ATI RAGE PRO
Turbo 3D akselleratsiey with 2D/3D graphics


     Two built-in speaker with support
The SRS Integrated microphone connectors
input / output


     Keyboard Apple USB: - Change
angle of the keyboard - Works well
as a USB hub

     Apple USB Mouse


     Height: 39, 5 cm with stand

     Width: 38 cm

     Depth: 44 cm

     Weight: 17, 3 kg


     Display mode


     Mode Frequency maximum resolution of 640x480 117 Hz, 
24-bit, millions of colors 800x600 95 Hz, 24-bit, millions of 
colors 1, 024x768 75 Hz, 24-bit, millions of colors




     The reaction to the emergence of iMac in the U.S.:



     "IMac - it's Christmas in August! -
said Paul Ramirez, vice president of
Marketing ComputerWare. "We sold over
One Saturday iMac computers more than
All desktop PC in July. "


     "IMac 'and sold the majority of our dealers this weekend," 
- said Steve Jobs (temporary manager (CEO)

Apple). "Until next week we will launch in stores, tens of 
thousands iMac 's. "



     "IMac might be one of the most
selling models at all times. When
the sales process goes, may be sold
several million cars, "- says
Roger Kay, an analyst at IDC. Jim Helpin,
executive director of chain stores
CompUSA, said that sales of iMac will
in history. "If this weekend we'll sell all the computers that 
we have it will be the best-selling iMac computer, which we 
have ever seen. " 


     Representatives of the chain stores MacMall
say they can not meet
all orders. "We sold 1,200 units. Only
this morning, "- said one of the managers
Sales MacMall.


     In the less than five months, iMac became
best-selling computer in the U.S., it was
sold 800 thousand units (more than
PC). About 55% of users are
adherents of the old Mac, 32%
first purchased a computer and 13% - the former users of 
"normal" PC. 

     In Moscow, iMac 266 costs about $ 1250,
iMac 333 - 1450 $.

     According to the test BYTEmark iMac 266
half times faster than Pentium II 450MHz,
and two times than the Celeron 333MHz.


     In early 1999, Apple released
new Mac for the professional market - Power Mac G3, the amazing 
buildings - a transparent plastic saturated blue and 
milky-white flowers, combined with faired.




     Inside:


     PowerPC G3 processor with a clock frequency of 300 -, 350 
- or 400-MHz, 512 KB or 1 MB cache second level, type

backside, on the processor module with a frequency of 150 -, 
175 - or 200 MHz respectively depending on the speed of the 
processor system bus is 100 MHz Integrated co-processor for 
floating point operations, and 64K processor cache, the first 
level (32K for data and 32KB for instructions) 


     64 MB or 128 MB of RAM
Four types of PC100 SDRAM memory expansion slot
DIMM, supporting up to 1GB of memory type
PC100 SDRAM, with the following
DIMM'ov: 32MB, 64 MB or 128 MB (64-bit
64-bit technology) 128 MB or 256 MB
(64-bit, 128-bit technology)


     Drives:
6GB hard drive or 12GB Ultra ATA or
9GB Ultra2 LVD SCSI card with Ultra2
LVD SCSI PCI 24-speed (maximum)
CD-ROM or 5-speed (maximum)
DVD-ROM with DVD-Video playback (reads CD-ROMs at 35) Zip-drive 
(some configurations) Place two additional Ultra ATA, UltraWide

SCSI or Ultra2LVD SCSI drives

Two FireWire 400 Mb / s
Two-port 12-Mbps Universal Serial Bus
(USB)
Port Apple Desktop Bus (ADB)

Built-in Ethernet 10BASE-T/100BASE-TX
(RJ-45)
Additionally possible to install an internal modem 56K 
(supports K56flex standards and V. 90) 

Four slots PCI: three 64-bit slots
frequency of 33 MHz and one 32-bit slot
with a frequency of 66 MHz allocated to
Graphics Card: ATI RAGE 128

15-pin mini D-Sub VGA connector and
Macintosh-VGA adapter

Minijack input / output 16-bit
stereo, with a frequency of 44. 1 kHz
Built-in speaker


     Graphics Card ATI RAGE 128
16MB memory SDRAM, providing
following features:

     2D acceleration
128-bit internal accelerator
Hardware accelerator graphics and video
Supports resolutions up to 1.920 x
1.200 pixels at 32 bits per pixel
(Millions of colors)

     3D acceleration
Advanced integrated aksellerator
Single-pass processing multitexture
Full 32-bit per pixel (b / n) Z buffer
and 8-b / n "stencil" buffer
Sustained support QuickDraw 3D RAVE and
OpenGL


     Keyboard Apple USB Keyboard and Mouse
Apple USB Mouse


     Power consumption (without monitor): 200W


     Height: 43, 2 cm

     Width: 22, 6 cm

     Depth: 46, 7 cm

     Weight: 13, 0 kg



     In tests BYTEmark computers
PowerPC G3/400 more than twice
faster computers Compaq Deskpro
Pentium II/450.


     To gain access to the connectors
extensions, pull the ring
on the side wall of the housing and open it -
all the boards are mounted directly on it. As
and IMac 's no floppy drive and
support SCSI. To use SCSI -
devices necessary to establish an appropriate fee in one of the 
connectors PCI.




     For lovers of Notebook'ov Apple releases Powerbook: 
elegantly rounded shape, translucent orange-molochnobely 
housing. 


     Each model comes with two
built-in expansion slots (which
can also be used as slots
batteries), including two slots PC
Card.



     Inside: 233, 266, or 300 MHz
PowerPC G3 processor, 1MB backside level
2 cache at 266 and 300 MHz processor module, 125 or 146 MHz 
64-bit backside-bus, 66 or 83 MHz system

Bus. Integrated module for floating point and cache 64K level 1 
on-chip (32K data and 32K instruction) or 32MB

64MB RAM; 2 x SO-DIMM, support
Up to 192 MB memory, 4MB ROM.


     Internal 2GB, 4GB, or 8GB IDE
Winchester, 2 expansion slots 3. 5 "
CD-ROM or DVD-ROM and other devices
Removable storage drive 3.
5 "1. 44MB memory expansion slot for 20-speed (maximum) CD-ROM 
for expansion slots 


     Port Apple Desktop Bus (ADB)

     -SCSI-port is not less than seven
peripherals

     -Serial (RS-422) port

     Port Power Adapter


     Built-in 10BASE-T connector
Ethernet (10 Mbps)

     Modem RJ-11 port supports
K56flex modem

     Infrared-(4-Mbps IrDA)


     -PC Card slot for two Type II PC
Cards or one Type III PC Card or
CardBus cards


     -S-video output connector

     -24-bit video out connector port (VGA-style connector)

     Sound:

     -16-bit CD-quality stereo input /
output


     Video:

     2MB, 4MB SGRAM, or VRAM supports millions of colors on 
external monitors up to 20 inches 

     -2D/3D Graphics via an integrated video controller

     -Support for Zoomed Video
in the lower PC Card slot

     Display:

     -14. 1-inch (diagonal) built-in display TFT XGA 
active-matrix supports millions of colors at

resolution 1, 024h768 pixels


     Two built-in stereo speakers


     Battery: 49 Watt / hour lithium-ion.
Average life: up to 3. 5 hours on one battery, up to 7 hours on 
two batteries under normal use



     Built-in full-size keyboard
76 (US) or 77 (ISO) keys,
including 12 function keys


     Apple track pad


     Depth: 26. 4 cm

     Width: 32. 3 cm

     Height: 5. 1 cm;

             5. 3 cm to 14. 1-inch
Model Weight (depending on configuration);
computer with a modem, battery and CD-ROM
weighs 3, 5 kg


     At this while you can and finish the story about the 
history of Apple and Macintosh. Why so far? - Because

Apple is not going to turn up today:
shares on the market grows, sales iMak 's
too, so much so that in some regions of the world's foremost 
dealers in the face - all lacking! A recently published 
information that the Korean firm Daewoo Telekom and its

a subsidiary of Future Power PC are going to sell in packages 
under "IMac", Apple has already filed them in court.

Looks like to make money on someone else's popularity.


     In the next issue will be continued
and a description of new models of Power Macintosh
processor G4.


     In the 7 th issue, I mentioned about the limit
performance of silicon in the 2 GHz, according
in press have misunderstood me - razyasnyayu: 2GHz - the limit 
for freestanding transistors, the information in 1989 for ten 
years, as far as I know, the situation has not changed. Started 
doped by different substances, to This had not previously used, 
the gain - A few percent of performance.

When a few million transistors
collected in 1 cm 2 they start to each other
interfere, and work properly, they can at
much lower frequency. Most importantly, the
increase the clock speed is now constrained
several factors:

     1. Conductive path between the
transistors are so close to each
from a friend that there are parasitic coupling
between them.

     2. Each transistor has a certain
input capacitance, the charge that it takes time to reduce the 
time carriers need to reduce the resistance of conductors 
(recently published "copper technology" to replace the 
aluminum, but it is "penny"). 

     3. In the process of manufacturing ICs
technology less than 0, 18 micron wavelength
ultraviolet radiation greater than the distance
created between the tracks, out in the
wavelength decreases, and this requires
creation of new photographs, a source
radiation, which does not exist yet.
So the winner will be the one who has to
crystal transistors smaller, better architecture. In this 
regard, Power PC exceeds the Pentium. Many have probably seen 
advertisement Pentium II, a sort of garbage Pobol audiotapes, 
and recently I decided to look in freshly bought PowerMac G3 
350 MHz, in hope to see such a "miracle." Pull the

for the ring, door opens, and there is visible only a small 
radiator 5h5h1 cm from He looks at one side of the board L2 
cache in 1MBayt, the CPU itself is hidden under this board 
seated in the connector such as the Socket 7. The shell 
thickness of less than 1 CPU, 5 mm, only in the place where the 
crystal and the adjacent sink, the thickness is increased to 5 
mm. 

     Immediately after the release for sale
Pentium III 600 MHz Intel to announce that in
soon (at least until the end of the year) to increase the clock 
speed is not going to (come:)), and will improve the processor 
architecture (finally). 

     And now about the sound.


     In the late 70's when there was a development
with Philips and Sony standard
AUDIO-CD, computers had relatively little RAM and performance of
applying them in digital audio is not
was the question. Nobody thought then about
sampling frequency, and that after 6 years
appear based on this technology synthesizers sound. Therefore, 
the standard 44100 has been taken from the ceiling (almost). 
True were isolated cases of otsifrovok: firm Roland in 1982 
released a rhythm box TR-808, using analog and digital sound 
synthesis, sound of drums created an analog generators, all

plates were recorded in the ROM in the digital
code.

     The frequency of 44,100 to digitize and clean
subsequent playback, fits, and for use in synthesizers are not
altogether, as it requires to create evenly tempered scale of 
large computational resources. In prinipe it

explains why it took so much
years before engineers turned their
eyes on this technology. By the mid-80's
power of computers grew, and there
the first sampling, with pleerami. Taken as a basis for 
derivatives and 44,100 - 22050, 11025, etc. Perhaps this 
contributed to the software used to create AUDIO-CD, or the 
fact that the first samples intended for scoring games, but not

playing music, and sampling rate did not play a big role.

     Since then, 44,100 - standard. But this
applicable to machines with tens of hundreds of MHz and the 
ILO. But what about the things we on SPECCY? Two years, there 
is a General Sound, but during this time he did not become

standard. It is unlikely that this contributed
high price of fees is likely bolnstvu people turned out to not 
need an old technology in 1985. In the previous issue 
introduced a new 8-bit 4-channel map with direct access to

's capacity - a good alternative to General
Sound, at least not a "black box"
and most can be assembled (according to the scheme
will cost 2 times less GS). But how
seen from the description, there are glitches, and to
again, in 1985. Fantasy-that whether people are missing? 
Fixated on a single the same.


     Now the frequency output in GS, with a side of drawn 
frequency 37, 5 kHz? It is not clear. Could not squeeze out 
more? All world tends to parallelize the computation,

here - again go its own way (all
saddled on the Z80). In the MIRACLE # 3 someone
Dmitry suggested that what is sold in GS limit for an 8-bit 
audio. For the GS is probably the limit, but not for an 8-bit 
audio. 

     First, a little theory.

     How many have already noticed, Speck
rather the optimal machine. When you create a
sound card, you must also use the "highlight", rather than 
trying to just copy the old stuff. 

     Regarding the use of samples for
scoring game, everything is clear - the effect is lost and all. 
But when you create a melody better if the samples could loop

to a certain place, and how much to lose. Every sound has 4 
phases: attack, decline, support and damping. At each of the

They can organizavat cycle and modulate the amplitude of all 
this, the sample will be very short, but it takes a lot of 
calculations. They can be reduced through proper organization 
of cycles. Cycle should be multiple of 2 ^ x bytes, for 
example: 256, 512, 1024 etc. (in the calculation of addresses 
Jr. byte is ignored). This in turn will impose some 
restrictions on the period, it must be exactly 2 "X bytes. 
There still some nuances, but I still miss them.


     To get the music needs a table
division factor. Better if they are integral and odnobaynymi. 
There are some factors that have very small error, they are 
also called "magic" (read more about it in "RADIO" 1990, No. 3, 
p. 63). In Once I trying to collect odnogolosy

digital synthesizer of "Moog" on Z80,
decided to calculate the coefficients of frequency division. 
Armed with a calculator, plunged into the calculation, in about 
2 weeks I found a single-byte series of numbers, which provides 
the minimum error. The next day, leafing through the "Radio"

I stumble on the above article -
I calculated the numbers were "the magic" 2 weeks "down the 
drain! :) Synthesizer was received with great systems.


     In view of samples 2 ^ X and
"Magic" of the coefficients for
system, where the La 1 octave = 440 Hz, the estimated frequency 
of O = 21,973 Hz. At the same time the resulting "average" 
system will be as same as natural. This frequency is not 
unique, there are other with the difference between the nearest 
2 ^ (1 / 12). 

     In the application of 21,973 Hz, all at the top
srezhutsya sound, with a linear transformation it will be 
noticeable. But there is a way of nonlinear transformation, 
where high frequency is better preserved and less distorted (it 
is described in detail "RADIO" 1991 number 11 (page 48) and 12

(P. 47): "... for music signals
maximum power is reduced to 6 dB
one octave, starting at 2 ... 4 kHz.
Therefore, if the device used
LPF 1-th order with a cutoff frequency equal to
2 ... 4 kHz, while the conversion and will come with the rise 
of frequencies above 2 ... 4 kHz at 6 dB per octave, it will 
not cause an overload at higher frequencies, but will 
significantly improve the quality of the conversion. "Producers 
various sound equipment because and increase the sampling rate 
and bit depth that using a linear transformation, and only this 
can save sound quality.


     Once I gathered the nonlinear converter is described in 
the magazine and used as the ADC-DAC reverb with a bit depth 10 
bits. Conducted tests in his home studio, one of those 
musicians who heard, no one said bad things about the sound 
quality: noise mixer and amp reverb turned out to be more noise,

hear the noise of the reverb, I was able to
only on a professional pulte Mackie
2002, which has a SNR
106 dB.

     In my opinion, this converter
is the signal to noise ratio is not less than 70 dB. At a 
frequency of 40 kHz in comparison with the original 
misstatement was not, a 25 bit reduced the top, but overall 
quality was quite high. 

     All these technical wisdom and
should be used when creating a sound card. Something I did not 
tell, but it already in next time.