[Blindapple] introduction

GUI Access guiaccess at covad.net
Wed Jul 27 01:59:22 EDT 2005


On emulating the Echo.  It would be technically possible, all be it 
in a roundabout manner.  The Echo stores the speech sounds it 
produces in LPC (Linear Predictive Coding).  So there's nothing 
particularly special about why the Echo sounds the way it sounds. 
You'd need to be able to grab high quality audio samples from an 
Echo, covering all of the individual speech phonemes the Echo can 
produce.

Directly getting the data off of the card or directly emulating the 
16 I/O lines which all Textalker's use to talk to the Echo is out of 
the question as this info is probably only known to a few people and 
getting this info in the year 2005 is highly unlikely.  I've heard 
that even APH who developed the most recent Textalker software ten 
years ago didn't know how this low-level code worked; it was written 
in the days of Street Electronics some 20 years ago and remained 
essentially unchanged.

So, my idea for an Echo emulator is to get your audio recordings of 
the Echo's speech sounds and write a patch to Textalker that instead 
of calling the low-level Echo code it'd call some code that'd do 
native assembling of the write speech sounds from the phonemes it was 
past and produce the desired speech.

There's lots more details that make this complicated.  I.e.  Getting 
the correct pitch (Echo's have 63 pitches), and getting the two 
correct rates (expanded/compressed).  There's probably more.  There's 
also the hardware freq pot on the Echo which allowed you to twiddle 
the frequency--totally independent of the ROM on the card.

At any rate while this is an idea I've toyed with for some ten years 
now, the likelyhood of actually doing it at this point is close to 
nil.

I'm just confident that a good approximation of the Echo is possible 
if someone had the time/money to make it happen.

Isn't it amazing that in technical terms a very minuscule 
text-to-speech synthesizer has managed to make as many inroads as has 
the Echo.  I've been tempted time and time again to assemble an Apple 
IIgs at work just to let others hear the Echo in all its glory.

Anyone ever have the pleasure of playing around with the music/sound 
generation capabilities of the Echo+?  Not many I know have owned 
this particular Echo, which is unfortunate as its the most 
feature-rich model of the family.  <SIGH>  Enough reminiscing...

GUI Access



>Hi.  As far as I know, I still have it.  I think I actually have a 
>couple different versions of it.  Getting it out of storage and into 
>a disk image form is a different matter though.  I was going to get 
>an IIgs but I've given up on that.  Besides I have nowhere to put it 
>and I don't know the first thing about imaging.  Also to be honest I 
>don't really have enough of an interest now to make it worth my 
>while.  I still like and collect Apple stuff, but I've pretty much 
>resigned myself to leaving my Apple stuff in storage permanently, at 
>least until I find lots of room to set up another computer.  I don't 
>have the luxury of a basement or other spare rooms, and I have three 
>or four computers set up already.
>
>Now, about emulating the Echo card.  This might be easier than you 
>would think.  Actually emulating the Echo sound would probably be 
>impossible.  You might as well forget about hearing an Echo voice 
>come out of your emulated Apple.  However, there might still be a 
>way.  I know of at least two emulators with source available. 
>Actually three, but one never got completed.  I am only talking 
>about emulators which are accessible.  One is called A2 and is 
>written in C.  The other is Applemu and is written in assembly so it 
>would be hard to port to anything but DOS.  The third is Appleemu 
>and is also in C and assembler but was never finished.  Probably the 
>easiest one to hack would be A2.  It runs best on Linux but can be 
>made to run under DOS.  Somehow it would need to be programmed to 
>set up a dummy card in slot 4 or somewhere that the Echo goes.  That 
>way you could run Textalker and it wouldn't crash.  Also somehow 
>that slot would have to route everything to a port, such as a serial 
>port.  What you could then do is plug in something like the DEC-Talk 
>Express into a serial port, run the emulator, brun textalker, and 
>you would have approximately the same thing as an Echo emulator.
>
>Now, if you know anything about speech, you will see one obvious 
>problem.  That is that the codes for the Litetalk, DEC-Talk etc are 
>completely different than the Echo.  Actually in that regard the 
>Litetalk would be the easiest to work with because the codes are 
>very similar.  My solution to that would be to write a new, 
>specialized Textalker or maybe look at Scat for the Doubletalk. 
>Someone would have to change all the codes to match the other 
>synthesizer.  Another option would be to do that within the program 
>itself.  In other words, when Control E, C is sent to slot 4, 
>increase the speech rate to 300 words per minute or something by 
>sending the [: code.  That would be a lot of extra programming 
>though, but Textalker is simple enough that it would not be 
>impossible.
>
>Finally, there is yet another idea which might work but I haven't 
>tested it.  I have an alternative screen reader for the Apple.  It 
>is not Textalker but is similar.  It's supposed to be compatible.  I 
>think, but I'm not sure, that I have source.  In that case, it's 
>just a matter of compiling that screen reader and using it in place 
>of Textalker.  Routing the slot to the serial port is easy, Applemu 
>will do it already.  A2 supports dumping anything sent to a printer 
>to a log file, so something similar could be done to send slot 4 to 
>Com1 or ttyS0.  Jayson also has this screen reader but it isn't 
>otherwise in general distribution.  Even if it doesn't have source, 
>I think it supports other synths easily enough.  Any thoughts?  Any 
>programmers on this list?
>
>At 05:13 AM 7/26/2005 -0400, you wrote:
>>Hi,
>>Sounds like Space Invaders to me.  Once again, I don't have this 
>>disk, but someone I talked to once had it.  Don't know if anybody 
>>here on this list still has it, but if so, we'd love to have it!
>>I do wish that an emulator did support the Echo synthesizer.  It'd 
>>have to be a Windows or Linux-based emulator, but if it were to 
>>emulate an Echo card, that would give us the accessibility to Apple 
>>stuff we want through the traditional Textalker software.
>>Jayson.
>
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