MockingBoard Mini-manual 9/96

[rubywand@aol.com (RUBYWAND)]

     Okay, here is the current version of the MockingBoard
Mini-manual. (Thanks to Edhel Iaur and Mike Mahon for much
valuable info on the later models.)  Corrections and additions are
welcome. 

MockingBoard Mini-manual (9/96 revision)

Part 1: Kinds of MockingBoards

    The original MockingBoards come in four basic 'flavors':

Sound I--    produces music tones and a variety of sound 
   effects (3 voices to 1 Audio Output)
Speech I--  produces speech or limited sound effects
  (1 voice output to 1 Audio Output)
Sound II--   2 x Sound I on a single board (3+3 voices
   to 2 Audio Outputs)
Sound/Speech I-- Sound I + Speech I on a single board
  (3+1 voices to 2 Audio Outputs)

Note ...
Audio Output: This goes to a speaker or hi-fi amplifier
Voice: a musical note, sound effect, speech sound, etc.


    Quite a few of the original MockingBoards were sold. Later MB's
use model names like "MockingBoard A", etc.. The main difference
between the original series and letter-named boards is wider
availability of Speech.

    Edhel Iaur and Mike Mahon supplied details on models A-D.
Prices are from a Sweet Micro Systems ad in the December, 1985
issue of  _A+_  magazine:

MockingBoard A is a stereo music and sound synthesizer with six 
voices.  Suggested retail price is $99.00. This model has two sockets
for adding speech synthesis IC's so that a user could add speech to
one or both Audio Outputs. Except for the speech upgrade options,
MB-A is very similar to the earlier Sound II.

"MockingBoard B" is just the name of the Speech Upgrade; it is not
a separate MB board. The kit consists of one speech synthesizer chip.
Earlier MB's used the 16-pin SC-01 speech IC, while later board runs
provided 24-pin sockets for the newer (but somewhat flawed) SSI-263
speech synthesizer chip. Suggested kit retail price is $89.00.

MockingBoard C is simply a MB-A that has been upgraded by plugging
in one speech chip. Suggested retail price is $179.00. (There was
an 'undocumented' upgrade, obtainable by plugging in the other speech
chip, which allowed the board to "sing harmony" with itself!) 

MockingBoard D is a stereo music, sound and speech synthesizer for the 
Apple IIc. It connects to a IIc through a serial port and is, of course,
external (unlike the Slot board models for other Apple II's).  Its drivers
are
very different from the slot I/O of the other MockingBoards. Suggested
retail price is $195.00.

Phasor is a MockingBoard-compatible sound card produced by Applied
Engineering. Looking at the software that comes with the Phasor may be
helpful to MB users. Phasors may still be available from ABC Direct
at 1-800-800-3680 for something around $100.


    MockingBoards work on Apple II's with at least 48K RAM. MB can go into
any Slot (except for MB-D, which must plug into a IIc). Most programs
expect
it to be in Slot 4; however, it is fairly common for a program which
supports
MB to ask you to enter the Slot #.

    Most for-MB products will work with Sound I, Sound II, Sound/Speech I,
A, and C. (Some work with D.)  Products that use MB include Ultima III,
Sky Fox, Wiley Byte', Thunder Bombs, Lancaster, Under Fire, Music
Construction Set, GuitarMaster, and Music Star.

    MB's 0.5 Watt Audio Output(s) can directly drive an 8 Ohm speaker.
You can also run the Output(s) to a hi-fi amplifier. 

    Except for speech-only models, MB uses the General Instruments
AY-3-8910 Programmable Sound Generator IC. The PSG has 3 on-chip
tone oscillators (via channels A, B ,C) and a Noise Generator (NG).
So, for example, the Sound II can play up to 6 notes or effects at once.
The NG on each PSG can be mixed with any, all, or none of the three tones.


    Many MB "Speech" version boards use the Votrax SC-01 Speech
Synthesizer IC. The SC-01 uses 64 phoneme sounds to produce speech.
MB software lets you adjust duration of each phoneme in 4 steps, create
"rules"
for custom sounds, and speak sentences from text in BASIC programs. The
SSI-263 speech synthesizer appeared on later model MB's. (At present, more
info on the SSI-263 is not included here.) 

    All MB versions use the 6522 Versatile Interface IC to handle board
I/O.
Except for the Sound I board, early models have circuit board points to
which you can add cables to utilize I/O ports not needed for Sound or
Speech.


Part 2: Sound Programming

    Each Programmable Sound Generator (PSG) has 3 output Channels: A, B,
and C. There are also 3 Tone oscillators, one committed to each Channel,
and one Noise Generator (NG) which can send its output to any Channel(s).
Amplitude (output Level or Volume) and Envelope Control ON/OFF is set for
each Channel. 

    The PSG's Enable/Disable register has 8 bits. Three bits let you
decide whether or not to send a Tone oscillator''s output to its Channel.
For example, you can enable Tone outputs for the oscillators going through
Channels A and B while disabling Tone output for the oscillator connected
to Channel C. 

    The Enable/Disable register also lets you decide whether or not to
send the Noise Generator's output through a Channel. Three bits let you
decide which Channel(s) the NG's output will go through. For example, you
can enable NG output through Channels A and C but not through B; or,
disable NG output through all three Channels, etc.. 

    If, for example, Channel A's Tone oscillator output is enabled and NG
output is enabled for Channel A, then, a mixed Tone + NG signal will go
through Channel A. Setting Channel A's Amplitude controls the Level for
the mixed signal.

    Often, a programmer will want to individually control the Levels of
Tone outputs (for music) and Noise outputs (for sound effects). This is
accomplished by using one PSG Channel only for Noise and two Channels only
for Tones. Since the MB Sound II has 2 PSG's, a typical game application
using the board will have 4 music tones and 2 effects sounds-- each
individually controlled for Level.

     More specifically, the user can set Tone Frequency (12 bits,
4 coarse & 8 fine) and Amplitude (4 bits) for each channel individually.
A fifth Amplitude bit lets you decide if a channel's Level will be "fixed"
(use the Level value)  or "variable" (i.e. follow the current Envelope
pattern).
You have 4 bits to set Noise Generator Frequency.

 Tone Freq = A2 Clock Freq/ [ (4096 x Coarse) + (16 x Fine) ]
 Noise Freq = A2 Clock Freq/ (16 x NG value) 

    The Envelope of the combined outputs of enabled sources can be 
controlled for Period (16 bits, 8 coarse & 8 fine)**  and, roughly, for
Shape (4 bits).

 Env Freq = A2 Clock Freq/ [ (65536 x Coarse) + (256 x Fine) ]

    The registers of the PSG are described briefly below:

Reg.  Function & Bit(s) used

00       A Freq. fine (0-7)
01       A Freq. coarse (0-3)
02       B Freq. fine (0-7)
03       B Freq. coarse (0-3)
04       C Freq. fine (0-7)
05       C Freq. coarse (0-3)
06       NG Freq. (0-4)
07       Enable =0/ Disable =1

  NG on A (5)  on B (4)  on C (3)
  Tone on A (2)  on B (1)  on C (0)
  Ex: Writing $F0 to Reg 07 plays tones A, B, C plus noise on C

08      A Level (0-3) and
     Envelope Control (4):  1 = Use Env;  0 = Use Level value

09      B Level (0-3) and ...
0A     C Level (0-3) and ...
0B     Envelope Period Fine (0-7)
0C     Envelope Period Coarse (0-7)
0D     Envelope Shape (four bits) 

  Continue (3)  0= do 1 cycle and set Level to zero
  Attack (2) 1= count up  0= count down
  Alternate (1)  1= reverse count direction each cycle
  Hold (0)  1= do 1 cycle and hold count


   To program the MB you write to the board's 6522 I/O chip(s). All
addresses
reference here are for a MB Sound II (2 Audio Outputs) in Slot 4.

$C400  ORB1  function to perform, OUT 1
$C480  ORB2  function to perform, OUT 2
$C401  ORA1  data, OUT 1
$C481  ORA2  data, OUT 2
$C402  DDRB1 data direction, OUT 1
$C482  DDRB2 data direction, OUT 2
$C403  DDRA1 data direction, OUT 1
$C483  DDRA2 data direction, OUT 2

Before sending music, etc. data to the MB you must Initialize the board's
I/O. To Initialize the 6522's: Store $FF at $C402 and the other three
DDRxx
addresses. This needs to be done by your program just once.

Your program gets access to a PSG via the 6522 by using a few basic
Function
codes which set the PSG's I/O control lines:
  
  Set Inactive = $04  Set PSG Reg# = $07   Write Data = $06   Reset = $00


To Write to a PSG register: Tell the PSG which Register you wish to access
(i.e. Set the "current register" #) and Write the data. This is easiest to
do
with subroutines to handle the basic Functions.   

Example Subroutines (for Output Channel 1):

Set Reg #     1000:  A9 07   8D 00 C4   A9 04   8D 00 C4   60

Write Data    100B:  A9 06   8D 00 C4   A9 04   8D 00 C4   60

Notice that each Function sub ends by setting the PSG control lines to
Inactive. 

Similarly, to do a Reset (set all PSG regs to zero) ...

Reset           1016:  A9 00   8D 00 C4   A9 04   8D 00 C4   60


To put the value $55 in PSG Register 02 (Channel B Freq. fine) ....

1080: A9 02         put Reg#  in A
1082: 8D 01 C4    store A at the Data address ORA1
1085: 20 00 10     JSR to Set Reg#  (sets "current register" to Register
2) 
1088: A9 55         put the value $55 in A
108A: 8D 01 C4    store A at the Data address ORA1
108D: 20 0B 10    JSR to Write Data  ($55 goes into PSG Register 2)
1090: 60              Exit from subroutine

Rubywand