Cheetah Sweet Talker doc/test?

[system11]

An an aside don't use the zxpand+ with a memopak 16... Hopefully no long term damage was done but the regulators on the back of the zxpand will start burning like the sun for some reason, within a second of powering on they'll give you a burn!

[Moggy]

Yup done by Cheetah!

I have two at the moment and have had a couple more in the past which I let go and they all had the crappy "hand made" drilling!

If you find it too loud by the way just undo the case and on the board you will see the little 386 op-amp which does the noise bit.
This has been set at a x200 gain which I find too loud for a small room close up. Remove the small 10uf capacitor that connects to pins 1 and 8 of this chip. This will knock it down to a more manageable x20 gain. Always test with the case assembled as it adds a bit in way of perceived volume whereas out of the case the speaker sounds too quiet.

[Moggy]

An an aside don't use the zxpand+ with a memopak 16... Hopefully no long term damage was done but the regulators on the back of the zxpand will start burning like the sun for some reason.

If you're using the Sinclair power pack then the 5 volt reg burns hot anyway,( something I've discussed/argued ad-nausea with the spands creator ) try using something around the 7.5volt mark for a power supply and things run a damn sight cooler.

[Moggy]

Nice recording by the way, it seems you're getting the hang of it and gaining some enjoyment to boot. Great stuff.

[system11]

An an aside don't use the zxpand+ with a memopak 16... Hopefully no long term damage was done but the regulators on the back of the zxpand will start burning like the sun for some reason.

If you're using the Sinclair power pack then the 5 volt reg burns hot anyway,( something I've discussed/argued ad-nausea with the spands creator ) try using something around the 7.5volt mark for a power supply and things run a damn sight cooler.

Oh by hot I mean 'this is obviously shorting out' levels of immediate extreme temperature. I tried with a Memotech HRG in the middle, and a few other peripherals and those are all fine. The Memopak 16 drives it to 'will fail or desolder itself' hot in a few seconds.

[stroebeljc]

The Parrot is similar except it allows you to read the port to know when you are clear to send the next allophone. Does anyone know if the Sweet Talker can do the same?

Update:
I answered my own question. Here is the link to retrieve the program:
https://worldofspectrum.net/item/0010467/

[stroebeljc]

Update:
I answered my own question. Here is the link to retrieve the program:
https://worldofspectrum.net/item/0010467/

I will slightly expand on this statement. There is only an OUT instruction to write each allophone. So what causes the Speccy to pause for the proper amount of time before allowing the program to continue? I think the Sweet Talker asserts the WAIT line to hold the CPU in limbo during speech processing.
However, the ZX81 version may not, since doing so would introduce video synchronization issues. Maybe adding a pause is the only way to get it to work on the Zeddy.
Still looking for a definitive answer.

[Moggy]

Taking my own Sweet Talker as the example (used on a Zeddy) there is a small transistor/resistor jobby on the board and after some experimentation I discovered that lowering the resistor value caused fast garbled speech, increasing it caused a slow drawl so can only assume that this is what dictates the speech speed. Removal of the transistor and resistor still allows the unit to work but a large PAUSE statement has to be added when using BASIC for example to hear intelligible speech, which again confirms the above I feel.

I believe everything stops on the Zeddy except for screen flicker when the S/T is speaking and in my own case a small daughterboard was added to it by Sir Morris to change the units port assignment from port 7 to port 128, which gets rid of the flicker.

[stroebeljc]

Moggy,
Can you tell if the RD or WAIT lines are connected anywhere on the Sweet Talker board?

BTW,
I'd love to see pictures of your circuit board.

[1024MAK]

I would be surprised if they are using the /WAIT control line for any length of time. If the Z80 is held for too long, any DRAM that needs refresh via the Z80 refresh cycle will not be refreshed. And all other execution is also “paused”.

The /WAIT input is only intended to pause the Z80 for one, two or maybe three T-states (clock periods) so that a slow memory or slow I/O device can complete a data bus cycle.

Either, a register is able to be read that reflects if the operation has completed or the software has another method of timing how long the current operation takes.

As I don’t have the hardware, I can only speculate...

Mark