[Blindapple] source for echo II

Jayson Smith jaybird at bluegrasspals.com
Fri Jan 29 11:49:13 EST 2016


Hi,

The problem is that the Echo card itself has absolutely no ability to 
generate speech from text. All the Echo really is, when it comes right 
down to it, is a chip that turns a certain type of LPC data into sound. 
That's all it is.

The Textalker software running on the Apple, and using the Apple's 
processor, memory, etc. turns text into phonemes, then turns those 
phonemes into the proper control signals and timings to send to the Echo 
card to generate the right sounds. So when you hear Echo speech, all but 
the last step, that of actually generating the sound you hear, was done 
in software running on the Apple.

If the Textalker source code still exists anywhere, I don't know it, and 
wouldn't know who to ask. Even if it did, it would almost certainly be 
written in 6502 assembly, the 6502 and its variants being the 
microprocessor used by Apple II computers. There was a version of the 
Echo for PC, but again, the Textalker software would probably have been 
written in 8086 assembly.

The bottom line is that emulating the hardware would probably not be a 
problem, but that wouldn't get you much. Textalker would probably have 
to be completely rewritten from scratch in order for it to work on 
anything modern.

A possibly more attractive idea would be to have a really stripped down 
Apple emulator which did emulate the Echo card, and create a custom disk 
for it which could interface with NVDA running on the PC in order to 
have the Echo act as a speech synthesizer plugin for NVDA.

Jayson

On 1/27/2016 1:16 AM, Guillem León wrote:
> Hi,
> Yes, MESS itself is completely open-source. The problem is that the Echo II card is being directly emulated. So if you wanted to use it in external applications you would have to find a way to get that emulation working for all the parts of the card (the TMS5220, the text-to-speech part, the audio output) and I'm not sure how that would work.
>
>> On 27 Jan 2016, at 05:06, Jason Custer <jscuster at gmail.com> wrote:
>>
>> Hi.
>>
>> Really enjoying the apple emulator, takes me back. Just curious, is the code for the echo II open source? Just curious.
>>
>> Thanks,
>> Jason
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