Capture savegame as audio?

[lennart]

Hey guys,
I recently rebought my childhood computer, a cpc464, after I stumbled over it on eBay.
This feels a bit like Christmas '84 again - you can probably relate.
Anyway, the CPC in near mint condition but I plan to upgrade and refurbish it a bit.
New driver belts for the tape are already in the mail. I also plan to add an audio in jack to it, just in case.
I was was wondering about audio out though. I will be playing elite again and I will need to save the game. Are there solder points where I can grab the audio out as well?


Cheers
Lennart

[rpalmer]

The audio data comes from the Ay-3-8912.

The cassette data comes from the 8255 (ports B - bit 7 for RD data and port C - motor control and WR data). I understand the sound line on the cassette port is primarily for sync pulses to time the data, this is what is heard when data is either saved or loaded to/from cassette as it is also passed to the audio circuit.

You cannot capture audio as if it were data, since they are from different sources and are quite different.

rpalmer

[Zoe Robinson]

It would be really useful to be able to save data as audio, I have to admit. Imagine the ease of creating CDT files from your own type-ins, etc. rather than faffing about saving to a cassette and then converting that to a WAV to recompile as CDT.


Ah, we can dream.

[Chinnery]

Are there solder points where I can grab the audio out as well?

This is actually quite an easy mod to do. I've done it on my 464, so have 2 3.5mm jacks on the back and a teeny hidden switch to swap between the internal tape drive and an external. I'm sure the docs are to be found, but from memory you just need a link from gnd and blue* on the cassette deck to a 3.5mm plug.


If I get time, I'll open the wee beast and have a look.



(*it may be green, was a while back)


[Edit]
This is the guide I followed. It is in Spanish, but with a small help from google translate it was easy to follow.
http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/hi-has-anyone-ever-done-the-tape-in-mod-on-a-cpc-464/?action=dlattach;attach=4642

[arnoldemu]

I was was wondering about audio out though. I will be playing elite again and I will need to save the game. Are there solder points where I can grab the audio out as well?

If your tape drive on your 464 is working you can record the save game to tape using the build in tape deck. Make sure you use the cassette version of the game.


If you are referring to the actual played sound, then you can connect to "SOUND" on the expansion port. This is mono sound from the AY sound chip.
Alternatively you can use the stereo sound from the AY chip through the 3.5mm audio jack.

[arnoldemu]

The audio data comes from the Ay-3-8912.

The cassette data comes from the 8255 (ports B - bit 7 for RD data and port C - motor control and WR data). I understand the sound line on the cassette port is primarily for sync pulses to time the data, this is what is heard when data is either saved or loaded to/from cassette as it is also passed to the audio circuit.

My understanding is different.


The sync and data are all part of the data from the 8255. There is no additional sync.


The cassette sound you hear from the speaker is from leaking in the op-amps I believe.


The SOUND on the cassette is the same as the SOUND on the expansion and is the mixed AY sound.