Date   : Mon, 12 Sep 2005 08:45:15 +0100
From   : Sprow <info@...>
Subject: Re: 101 uses for a speech system (number 47)

In article <4324AE3E.8080406@...>,
   W.Scholten <whs@...> wrote:
> Sprow wrote:

> > Hi,
> > The original speech system upgrade came supplied, in the UK at least, 
> > with a
> > dictionary of words spoken by newsreader Kenneth Kendall in an english
> > accent.
>
> I'll have to check the US beeb for the speech ROM someday...

Why bother, just fit an reprogrammable speech system in a normal beeb!!

> Btw, can the bank number be reprogrammed by software or a switch? Also, 
> what I'd really like to see (a is the speech emulator you made but with a 
> larger PCB with 
> socket for the original speech PHROM. Would be cool to have both using 
> the emulator with a different bank number.

Space wise (bearing in mind the 1770 interface hovers over the TMS5220) I
think it would probably make more sense just to fit a micro with another 16k
of flash ROM, such that one emulator decodes 2 bank addresses. I could
probably do that as a special for you if you ask really nicely.

The bank number is set at assembly time, so can't be reprogrammed (there'd
be a problem there since you need the bank number in order to know where to
send the programming command). 

There are however 3 spare option links on the back of the board along with
all of the other components you can't see in the photo, one of those links
could perhaps be used to set one of the bits of the bank number?


> As to PCB cost:
>
> [ IDE card with 8K/32K RAM ]

> > but due to space constraints on the IDE PCB conflicting with the 
> > desire to
> > use DIL parts there's no SRAM.
>
> By space constraints you mean it'll cost a lot more for a somewhat
> bigger PCB at the place you had them made? If so, how much more?

Not quite, rather that the PCB size was a fixed design parameter, as was the
desire to use all DIL components. You run out of space quite quickly that
way.

As I was doing the layout for JGH, his requests get higher priority. I'd
have probably gone for a programmable logic device and all surface mount,
but that's just me, and means it's no longer made from off-the-shelf parts.

> I've checked the cost increase for different sized PCBs for one firm (in
> NL) that had all the prices on the web (incl. drilling holes etc.), and 
> it wasn't much at all...

PCBs per square inch adder is small I agree, most of your money goes on
setup,
Sprow.