El Nov 7, 2014, a las 4:17 PM, Jules Richardson <jules.richardson99 at gmail.com> escribi?: Votrax speech synth This will fill in some blanks: http://www.classiccmp.org/cini/pdf/pe/1982/CE1982-Dec-pg47.pdf Francois

The SC01 is a well-known Votrax speech synthesiser IC. I am sure you can find a data sheet somewhere (I have it, I think, but my stuff is still packed after the move!). A 24 pin ROM is not going to be more than 8K (It would be useful to know how big it is). You _might_ get text-to-speech in that. With no UART, I guess it bit-bangs the serial protocol (I am surprised there's no CDP1854 on the board). Pity. If there was a UART you could stick a 'scope on the baud clock input and find out what bit rate to use. -tony

If it's bit-banged, I find it plausible; taking a highly oversampled CR character and deducing the effective divisor from it is relatively easy. Back in the '80s, I played with a Votrax-branded speech synth. Based on rather fuzzy memory from that, you want 8N1 or 701 - IIRC the protocol stuck to ASCII, in which case 8N and 70 are equivalent. Unfortunately all I can recall of the protocol - even assuming it's the same on the device I used as on the device at hand here - is that it used short sequences (two? three? octets) to specify various phonemes, with conversion, if any, from spelling to phonemes happening on the host. /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML mouse at rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

As described, this can't work if the sender's speed is slower than 1/10 of the receiver's speed, because then the receiver's entire character time falls within the sender's start bit. (Of course, that's enough to span a factor of 8, which is enough to be somewhat useful; it allows autobauding from 9600 down as low as 1200, for example: 0x0d=N, 0xe6=N/2, 0x78 with a framing error = N/4, 0x80=N/8, 0x00 with a framing error = N/10 or slower.) Handling faster speeds is more difficult, and may vary based on details such as whether the sender's speed is slightly more or slightly less than (say) double the receiver's speed. But, if it's bit-banged, then simply greatly oversampling the autobaud input can allow autobauding even to unusual speeds like 4000 baud, provided they're within range. I said 701, not 7O1. I initially wrote 7Z1, but its converse is ambiguous (because "one" and "odd" both begin with o). I didn't think of M and S; I wish I had, because the set M S E O is less likely to display ambiguously than 0 1 E O. /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML mouse at rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

You know, this entire discussion requires a user to reliably hit the RETURN key. At least once, at the right time, and after connecting with a modem, or whatever. I have never had any confidence in a human _ever_following instructions. I worked for a few years with a woman who always used the line feed key instead of CR (or return, or enter, call it what you will, decimal 13). I found that cycling through a limited list of baudrates based on framing errors, waiting for the BREAK signal, was more reliable.

No, the keyboard will always generate a CR (CTRL-M, 0x0d) when the return/enter/whatever key is pressed. Unix/Linux line discipline translates it into an LF (if, IIRC, ICRNL is set). The semantics for stty change from Unix to Unix, but a CR is always decimal 13, a line feed is always decimal 10. Check "man ascii".

Am I the only one who finds it hilarious that this statement was posted with paragraph-length lines - ie, without hitting RETURN? Yes, and a human who tries to type Dvorak on a QWERTY keyboard will lose too. There's only so much broken-user it's reasonable to try to accommodate. In the case of a speech synth that takes phoneme codes rather than natural-language text, I see nothing wrong with assuming it's going to be talking to software rather than a human, possibly excepting debugging (and debuggers can usually be trusted to be more capable of adhering to protocol than end users such as the woman you describe). /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML mouse at rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B