Mist and an audio input... is it possible?

[javidoom]

Hi!

I'm wondering if there is any solution to have an audio input in the mist... I would love to load my Spectrum games on tape.

Is it hardware possible?

Thanks.
Regards.

[lips2k15]

I too was thinking about this... maybe route the tape audio input the current core uses to send its loading sounds to the fpga ula so it goes from one of the db9 joystick ports instead - it would only need to 2 pins a signal and a ground and would be easy to wire up a cable to plug into a cassette recorder!!!

[ericgus]

I too was thinking about this... maybe route the tape audio input the current core uses to send its loading sounds to the fpga ula so it goes from one of the db9 joystick ports instead - it would only need to 2 pins a signal and a ground and would be easy to wire up a cable to plug into a cassette recorder!!!

If I read the schematic correctly the DB9 controllers connect to the ARM processor not the FPGA ..

[Sorgelig]

AUDIO_OUT can be used as input if core configure it so. I'm not sure if FPGA can implement comparator inside. If no, then external comparator circuit is required to make logic levels from audio wave.

[lips2k15]

how about the internal io header that the mist midi board connects to? or how about actually loading through the actual midi ports?

[Sorgelig]

Any FPGA pin (except specific non-configurable) can be input and output.
There is no difference between AUDIO output pin and midi pin. The only difference, that audio has some resistors and capacitors connected - but they shouldn't interfere audio input.

[lips2k15]

this whole topic has reminded me of the codemasters cd games pack from way back!!!

[javidoom]

So, if it's possible, this could be a great addition to your Spectrum core Sorgelig.
I have so many tapes waiting to be loaded again...

I would help if I had the knowledge...

Regards.

[leech]

Hmm, anyone consider maybe a USB adapter? There are plenty of audio-in ones out there. Not sure what drivers or such would be required for the translation there.

[javidoom]

The V6z80p FPGA has an audio cable with some kind of components... maybe it could be something similar?

[Sorgelig]

So, if it's possible, this could be a great addition to your Spectrum core Sorgelig.
I have so many tapes waiting to be loaded again...

I would help if I had the knowledge...

Regards.

Why don't use PC to convert your tapes into TAP or CSW files once and forget about it?

[Sorgelig]

The V6z80p FPGA has an audio cable with some kind of components... maybe it could be something similar?

This circuit should be compatible with RS232 FPGA header used for MIDI on the MiST.
It's possible to add support but i'm not going to make this circuit for testing.

[javidoom]

I understand.

I have the whole wos collection converted to CSW and most of the times, I used them instead tap files.

I also have a lot of original tapes too, and as zxuno, and v6 both load from tapes, I though you maybe would like to give it a try.

It's nostalgic.. . and for me, it's a pleasure to load my childhood tapes.

But it's ok, I understand it's a lot of work. Just I was thinking about give more perfection to an already perfect core, if it was easier to do

Regards.

[Sorgelig]

Not much work, but i cannot test it.

[Sorgelig]

Ok, since you ask for it, you are responsible for test

Attached version supports the circuit you've posted above.
You need to connect it to SV2 connector of MiST board.

I suggest to connect TX pin of this adaptor to PIN2 of SV2. It provides +3.3V for stable supply. For compatibility, my core also set logic 1 to TX (PIN 4) but i suggest to use PIN2.

i.e. connect this way:
adapter --> MiST (SV2)
TX --------> PIN2
RX --------> PIN3
GND ------> PIN1

use https://github.com/mist-devel/mist-boar ... ematic.pdf for schematic reference and https://github.com/mist-devel/mist-boar ... 13_pcb.pdf for locating the connector.

If your MiST board uses MIDI daughter board, then you need to disconnect RX(PIN3) from it.

[javidoom]

Sure I will help!!!!

Let me go to the store to buy and adaptor for the cable and I'll make the tests

I'll keep you informed!!

Thanks!!
Regards.

[javidoom]

Ok, ok, ok.......

If we add this:



to this:



and a good ammount of Sorgelig Magic, we get:



IT WORKSSSS!!! FLAWLESSLY!!!!!


Yeahhhh!!!!!!

My board was bought assembled with the midi from Lotharek, so I tried to unsolder it.


But I couldn't... as I lack the skill and tools... so


I decided to cut the connector


Using some old pc jumper cables


And a little of soldering skill


(This is the V6 cable):


Ohohoh!!! This core cannot get better!!!

MANY THANKSSSS!!!!!!

I need now, think a way to clean all of this....

[ericgus]

Sorgelig how difficult is it to enable the MiST midi serial lines like you did with the spectrum core for other cores say the C64 core to enable ttl serial connections via the same midi pins on the MiST board? Just curious..

I only ask as I am looking at the core source in Quartus and trying to figure this same sort of mod out to enable serial comms on the c64 user port.

[kripton67]

It's great. Thanks Sorgelig.

[Sorgelig]

Sorgelig how difficult is it to enable the MiST midi serial lines like you did with the spectrum core for other cores say the C64 core to enable ttl serial connections via the same midi pins on the MiST board? Just curious..

I only ask as I am looking at the core source in Quartus and trying to figure this same sort of mod out to enable serial comms on the c64 user port.

Adding audio_in was very simple since it's just one wire to Spectrum's port.

As for C64 - everything is going through very specific chips. So, i have no idea how RS232 is connected in C64 and if all required chips are properly emulated.

IT WORKSSSS!!! FLAWLESSLY!!!!!

Thanks for testing!
Actually you could cut only one - PIN3 from MIDI and add some switch between PIN3 from MIDI and audio_in.

[Sorgelig]

The release with audio in is on my repository.

[ericgus]

As for C64 - everything is going through very specific chips. So, i have no idea how RS232 is connected in C64 and if all required chips are properly emulated.

Its just pins M (tx), B+C (rx) on the CIA #2 .. but you are right that its specific chips, ok thanks I'll take a look and try to sort out if that chip is even in my copy of the c64 core source.

[javidoom]

Hi.

I've cleaned the mess, and added a new connector for the audio_in



Now I can load all my tapes... COOOOL!



Regards.

[ericgus]

javidoom - I love your solution for running the lines outside the MiST .. Need to look up those connectors and get a set. By any chance do you have the name/part# for those types of connectors?

Sorgelig - I looked into it and it does seem the C64 CIA implementation may not be complete in fpga64, however the MINIMIG (amiga core) does have a working CIA compatible chip fpga implementation, the Amiga uses a socket compatible CIA chip to do the same function as the 64 (on real machines they often repair defective c64 CIA's with a spare Amiga CIA chip), and since minimig is already in fpga source and the minimig ttl serial works for output on the mist midi connector this should work, just need to "copy" the 8520 chip from the minimig and "plug it" that into the c64 core. Thanks for the heads up I never would have looked into it and probably would have been really frustrated.

[duhproject]

Hi.

I've cleaned the mess, and added a new connector for the audio_in



Now I can load all my tapes... COOOOL!



Regards.

That plug looks AWESOME! Great project.