"The Atari A to Z"
                              by Mark S Baines
                      Copyright (c) 1998 Mark S Baines
                             All Rights Reserved


       YOU MUST READ "READ_ME.NOW" BEFORE YOU LOOK AT ANY OF THIS FILE
*****************************************************************************


Y


YM-2149
The Yamaha-made programmable sound generator chip used in the ST-Falcon range 
with three independently programmable tone generators, a programmable noise 
generator, a mixer for tone and noise, analog output, fifteen logarithmically 
raised volume levels and programmable envelopes. It comes in a 40-pin 0.6 inch 
DIL package and is based on the General Instruments AY-3-8190 family found in 
most 8-bit computers. It also performs a secondary function of controlling the 
computer's parallel printer port because of its two bidirectional 8-bit 
parallel ports. Each tone generator can produce a sound frequency from 30 Hz 
(just within audible range) to 125 kHz (far above audible range) on each 
channel. The amplitude or volume of each channel is programmable and each 
frequency can have its own envelope which is a description of its attack, 
decay, sustain and release characteristics. Such versatility can give each 
channel different effects, such as a constant tone, a rising or an oscillating 
one. Each channel can be mixed by programming with any number of others and 
wired together to be output via the monitor port pin 1. Using CPU intensive 
and effective programming, sound samples, such as speech or music, can also be 
output to this chip and played out through the monitor loudspeaker.


Ymodem
A data transfer protocol which is derived from the Xmodem protocol with CRC-16 
and 1 K blocks and incorporating a batch transmission facility so that many 
files can be transferred with one command. See Xmodem, Zmodem.


Y
2 entries
EOF