Voice Messenger - Speech 64

This is one of many speech synthesizer cartridges for the Commodore 64 (others were the COMvoice, the Magic Voice, the ProVoice, the Voice Master, etc.). This one seems to have arrived on the market in 1984, and it is incompatible with Commodore's Magic Voice, meaning that it is probably completely unsupported by software. But let's face it, in those days that didn't matter so much, because most personal computer owners could at least program in BASIC.

Unlike some other speech synthesizers of the day, the Voice Messenger didn't have a pre-set vocabulary. It could translate any text into speech, and the programmer could specify the sounds using what the Voice Messenger's manual calls "allophones", which seem to be roughly equivalent to the "phonemes" of the Amiga's narrator.

The Voice Messenger adds commands to Commodore BASIC, so that BASIC programmers can easily use the unit. The BASIC commands are:

The Voice Messenger has an allophone buffer, which can contain up to 256 allophones. The BASIC variable SP% reports how much space is left in the allophone buffer, so that the programmer can avoid buffer overflow. This is necessary because the BASIC program continues to execute as the voice syntesizer works. Multiple SAY commands in a row can easily fill the buffer. Nothing bad happens, but words that don't fit in the buffer are never spoken.

There is also support for intonation, but this only works if the Voice Messenger is given allophones instead of normal text. Allophones entered as capital letters are intoned UP, and allophones entered as lowercase letters are not intoned.

The manual includes instructions and sample code for using the Voice Messenger in assembly language (machine code). In machine code, allophones are programmed using numeric codes according to these tables (note that there are no allophones for the letters x or q):

Note that there are less than 64 allophones. It takes only six bits to define this number (bits 0 to 5). Bit 6 is for the voice (0 = low voice), and bit 7 is for intonation (1 = intonate up).

Here is the sample ASM code, reproduced from section 6 of manual:

INIT	SEI		;disable interrupts
	LDA $A7F0	;select Voice Messenger ROM
	JSR $A121	;call set up routine
	LDA $A7F0	;disable Voice Messenger ROM
	CLI		;enable interrupts
*	LDA $02BE
*	ORA #$20
*	STA $02BE
	RTS

	JSR INIT	;call initialization routine
	LDY #$00
WAIT	LDX $CE5F	;is buffer full?
	DEX
	BEQ WAIT	;wait if so
	LDA DATA,Y	;else get allophone
	BEQ FINISH	;exit if finished
	LDX $CE64
	STA $CF00,X	;store allophone in buffer
	INC $CE64	;and update pointer
	INY		;next allophone
	JMP WAIT

FINISH	RTS

DATA	DB $5B,$C7,$7E,$75	;the four data bytes
	DB 0			;end marker

	JSR INIT	;call initialization routine
	LDA $02BE
	AND #$FE
	STA $02BE	;select low voice
NEXT	LDA DATA,X	;get character
	STA $CE70,X	;and store it in buffer
	BEQ FINISH	;if last char (null byte)
	INX
	JMP NEXT

FINISH	INC $CE63	;start conversion
	RTS

DATA	DB 'THIS IS A DEMONSTRATION OF TEXT TO SPEECH CONVERSION'
	DB 0

	LDA #$0F
	STA $D418	;set sound to maximum
	LDX #$00
STATUS	LDA $DE00	;is speech chip ready?
	BPL STATUS	;wait if not
	LDA DATA,X	;else get allophone
	STA $DE01	;and send to low voice
	BEQ FINISH	;end if last allophone
	INX
	JMP STATUS	;get next one

FINISH	RTS

DATA	DB $1B,$87,$3E,$35
	DB 0		;end of data

One very interesting feature of the Voice Messenger is that the supplied cabling actually feeds the speech synthesizer's output into the C64's audio input. This should allow the C64 to modulate the voice.

SAY "A B C D E F G H I J K L M N O P Q R S T U V W X Y Z"

SAY "1  2  3  4  5  6  7  8  9  0"

SAY 0 "VOICE MESSENGER SPEECH SIXTY 4"

SAY 1 "VOICE MESSENGER SPEECH SIXTY 4"

SAY 0 "BY YOUR COMMAND"

SAY "[aaAAaaaaAA]"

SAY 0 "hhhhhh"

SAY "HROTHGARS COOL OLD JUNK PAGE"

This interesting device, in its original box and with manual and cabling, was donated to my collection by Frank McCormick, CoSysop and programmer of McBBS, one of the best BBSes in the city of Montreal from 1987 to 2000. Thanks Frank!