[Blindapple] Emulating Echo

[GUI Access]

>Hi.  Is there a way of finding out what it sends to the slot to 
>detect whether there is a real Echo or not?  I tried various tricks 
>to find out but as yet have been unsuccessful.  Obviously I know it 
>sends something because that is how the Doubletalk knows when to 
>switch.  Is there a way to patch Textalker to only look for a card 
>in slot 1?  I think I am reasonably close to making A2 simulate an 
>Echo but I need a way to trick Textalker into sending to slot 1 even 
>though there is no Echo there.  I know there is a way to do this 
>with the older versions, but what about the 3.1 APH series?  I 
>believe that even though we can't really ever use a real Echo under 
>emulation, it can be simulated fairly easily.  I played with this a 
>little and looked at the C source and it looks simple enough. 
>Aalas, if A2 only emulated sound!  However, if I can get something 
>going under A2, it might be possible to make it work with a better 
>emulator.  Please, if you know any C programmers, contact me!  This 
>would take a good programmer very little time to do since I think I 
>know what needs to be changed.
>
>For those interested, all this stuff is in jump.c and vidout.c.  The 
>jump.c opens a2.printlog if someone activates slot 1.  The vidout.c 
>is obviously for video output and opens a2.log if running under 
>Linux.  Both look simple enough and I think they could be easily 
>modified.  The only other thing I might need is a dump of the Echo 
>ROM, which I think is in the c400 range for slot 4 from within the 
>monitor.  I could very well have no idea what I'm talking about, but 
>I would like to try more experiments.  My initial attempt did work 
>reasonably well, but not quite good enough.


There is no Echo ROM that shows up in the $C100 - $C7FF address 
space.  Textalker looks at the I/O lines for each slot at $C090-$C09F 
for slot 1, $C0A0-$C0AF for slot 2, ... $C0F0-$C0FF for slot 7.  I 
have no idea what it looks for and/or what data it stuffs into these 
addresses to identify an Echo.  But all communicating with the Echo 
is through these addresses.

GUI Access




>
>If anyone else wants to try this, do the following from DOS.  First, 
>unload the screen reader and the synth drivers.  I use Vocal-Eyes so 
>I do "ve /u" and I use the DEC-Talk Express so I do "dtexp /u." 
>Then, assuming you are in com1, do the following:
>
>a2 >com1 disk.dsk
>
>Replace disk.dsk with a bootable disk.  Speech should come directly 
>out the synthesizer.  Try cataloging to make sure.  If something 
>bombs, hit Control C, "q" and enter.  If nothing happens, repeat. 
>Exit the DOS window or somehow reload your screen reader.  This 
>isn't perfect since you don't get review mode at all and it doesn't 
>always speak right away as it should, but it is a good start.  I 
>believe that it can be done, maybe easier than I thought. 
>Criticisms are welcome.
>
>Oh, I made a mistake about A2.  It is not licensed under the GPL. 
>Make sure to read the comments in the source before changing 
>anything.  It allows free copying and distribution, but it doesn't 
>comply with the GPL so may not be considered "free" by some people. 
>I'm not personally bothered by it, but others might be.
>
>At 08:21 PM 7/27/2005 -0400, you wrote:
>>Actually my Doubletalk can be freely switched between Echo and Doubletalk
>>mode.  To use Doubletalk, in Basic you just type pr#X where X is the slot
>>where the card is installed.  Then the card emulates a printer in that slot,
>>so anything sent to it will be spoken with the Doubletalk voice.  To use the
>>Echo emulation, which isn't perfect but does get the job done, you must load
>>the Textalker software as if you had a real Echo installed.
>>Jayson.
>
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