Hi Chris Yes, but this wasn't a screen-reader, or was it? My own little sub-routine utilised a little adapter and the Braid Systems speech synthesiser. It was a lot more expensive than your own solution which, I confess, I've never heard of until now. I am curious as to how this thing worked actually so maybe, just maybe, there was a way of accessing the screen on the C64 which I wasn't aware of. My own solution was very primitive, and there was no way to review the screen's content in any other way than live. So you had to be on your metal and listening intently to what was happening. There were also gaps because the high graphic content of a lot of C64 software simply couldn't be spoken properly. Those who used ASCII and ANSI to draw their graphics gave me a huge problem because the synth would just speek nonsense when it encountered those.
Gordon On 30 May 2012, at 17:19, Chris Moore <[email protected]> wrote: I used to have Currah speech for the c64. It was a cartridge that had a din cable coming out the back of it which you plugged into the audio 5 pin audio in socket next to the cartridge slot of the C64. I think it cost £29 at the time (1984) and you used the say command within your C64 basic to get it to speak. You can hear a sample at:http://www.youtube.com/watch?v=CBx1nTcVPEU&feature=related Chris On 29 May 2012, at 16:55, Martin McCormick wrote: > I figured at the time that a person could write an > interrupt service routine or an extra patch of code just as you > described. > > The Apple II had an interrupt but nothing on board used > it, not even the keyboard. I had a Mountain Hardware > clock/calendar board plugged in to the mother board which > actually did supply an interrupt once per second and I did play > with it a bit, but you had to butcher up the clock board to get > any more frequent interrupts than once per second and I just > didn't see the value in that at the time. > > As for the access interface, I started out with a > routine that fit in to low RAM which hooked the address for the > screen buffer and converted all the data that could be converted > in to Morse Code. That was sure a start since I already knew > Morse, but the TSI speech board and the Votrax were each a big > step up from the other. > > While we are on the topic, the sound generator in the > C64 was spectacular compared with anything else at the time. The > Apple II had a D-type flip-flop for both the loud speaker and > for the cassette tape interface. To make sounds, you addressed > which ever one of those devices you wanted and that would cause > the strobe to pulse which stepped the flip-flop from the state > it was in to the next state so, for example, to make a 1000 HZ > tone, you wrote a counter routine to hit that address 2000 times > a second which cycled it on then off, then on again for as many > times as your counter was set to loop. > > The IBM P.C. systems had a slightly more versatile noise > maker in that there was a programmable counter on a dedicated > chip which you could set to a 16-bit number which determined the > pitch of your tone. The counter/timer chip received a roughly > 1-MHZ clock signal and your tones were whatever frequency you > got by setting the counter to any number from 1 to 65535 with > that value giving you a buzz around 25 or 30 HZ. > > The C64, on the other hand could have generated speech > as it had a 3-voice chip as you mention below. > > Had my life gone a little differently, I probably would > have been really proficient in the C64 as it was quite the > machine in its day. > > You say, > >> As for the C64, I wrote a very rudimentary screen-reader which sat in RAM >> at location 679 and dumped everything textually sent to the video port to >> the C64's user port. In those days I had a little adapter which allowed >> me to interface a "Braid System" speech synthesizer to the C64 using its >> parallel input. The voice was dreadful, but not as bad as some of the >> more modern software speech implementation, such as that horrible DecTalk >> 32 that ships with Window-Eyes, and the DecTalk Express and DecTalk PC >> which used to be quite popular for some reason. > > DecTalk always reminded me of somebody who had had a few > too many or who had suffered some trauma that one might be > curious about but prudence would keep one from asking any > probing questions. > > You said, > >> The sound on the C64 was innovative for its day and could probably still >> hold a >> candle to some more modern hardware of its type. > > It definitely could. What we have here is evolution. DSP > chips of which the C64's sound generator is one are an example > of dedicated hardware doing one thing extremely well and it > probably wouldn't be worth a darn doing anything else. > > It sounds like we were playing with similar toys in the > eighties. I ended up learning the Motorola 68HC11 which is a > digital controller chip. It is a 6800 processor with some > timers, interrupts and an A/D converter. > > It had a monitor ROM one could use to develop > assembly-level programs so you could use it to control whatever > your imagination desired. The 68HC11 was originally designed to > be the engine control unit in 1980's-era cars. > > I had a lot of fun playing with the 68HC11 as it was a > lot like the 6502 except you could sure do a lot more addressing > modes and therefore more powerful programming. > > So long for now. > > Martin > > ======================================= > > The Techno-Chat E-Mail forum is guaranteed malware, spyware, Trojan, virus > and worm-free > > To modify your subscription options, please visit for forum's dedicated web > pages located at > http://mail.tft-bbs.co.uk/mailman/listinfo/techno-chat > > You can find an archive of all messages posted to the Techno-Chat group at > either of the following websites: > > http://mail.tft-bbs.co.uk/pipermail/techno-chat/index.html > > Or: > <http://www.mail-archive.com/[email protected]> > you may also subscribe to this list via RSS. 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