Midi/Joystick interface?

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Dbug
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Midi/Joystick interface?

Post by Dbug » Sat Jan 13, 2018 11:10 am

Hi,
a few (many) years ago, I was sent a small piece of hardware by Twilighte, which I believe is a midi interface, but since there's only one DIN connector and I never got the software for it, ultimately I've no idea how to use it.

I took a bunch of photos, hopefully one of you could tell me:
- What it is
- What the two switches on the board as made for
- If there's any software around that can be using it
- If it looks like this can be used at the same time as a microdisc

Thanks :)
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iss
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Re: Midi/Joystick interface?

Post by iss » Sat Jan 13, 2018 12:13 pm

It looks very close to the "MIDI/Minitel interface for Oric".
I think it's only MIDI and kind of serial interface, i.e. no joystick.

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Silicebit.
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Re: Midi/Joystick interface?

Post by Silicebit. » Sat Jan 13, 2018 12:24 pm

I agree with iss, it could be a MIDI/RS232 interface. http://oric.free.fr/hardware.html
Oric user since 1984. YouTube

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ibisum
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Re: Midi/Joystick interface?

Post by ibisum » Sat Jan 13, 2018 2:18 pm

Look for an Opto-isolator chip - the pics aren't clear enough for me to make them out, but maybe you can see them better Dbug? Those look like standard buffers, which would imply there's something UART'y going on, anyway.

And if it is MIDI, I'd love to see you get it working - MIDI on Oric has always been a fantasy of mine. And don't forget that even if its not a joystick interface, you can still use MIDI for joystick functionality .. like, the 4-way joystick on this MIDI controller could do joystick-for-game duties, for example:

http://www.akaipro.com/products/keyboar ... -mini-mkii

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Re: Midi/Joystick interface?

Post by Dbug » Sat Jan 13, 2018 3:23 pm

For what I saw, the components are:

SN74LS09N - Quad 2-input positive-AND gates with open collector outputs 14-PDIP 0 to 70
SN74LS74AN - Dual D-type pos.-edge-triggered flip-flops with preset and clear 14-PDIP 0 to 70
T74LS00BI - Quad 2-Input NAND Gate

S6551P - Async Communications Interface Adapter (ACIA)
1.8432 mhz crystal
WIMA 0.0022 - Capacitor
ICL232CPE/H9514 - DUAL LINE TRANSCEIVER, PDIP16, PLASTIC, DIP-16

There's also a few resistors and normal capacitors, two switches, and a small grey component with two legs, ceramic looking, black on the top, with an inscription that looks like N10 or A10.

Regarding the optocoupler, I don't know what they would look like, and regarding the Akai product, that one is a midi on USB so it would not directly be usable (my gf actually bought one last week, with the black and red design it totally look like it would work on the Oric!)

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Re: Midi/Joystick interface?

Post by NekoNoNiaow » Wed Apr 18, 2018 5:24 am

Dbug wrote:
Sat Jan 13, 2018 3:23 pm
SN74LS09N - Quad 2-input positive-AND gates with open collector outputs 14-PDIP 0 to 70
T74LS00BI - Quad 2-Input NAND Gate
These are likely used to decode the address present on the expansion bus and detect that this board should respond to data signals.
If you could trace the paths from the pins of these two chips to the corresponding pins on the expansion slot it would allow us to determine at which address it is responding.

This is obviously a fairly tedious exercise and it helps a lot to have a multimeter with a continuity testing mode which beeps when the two ends of each probe are connected electrically.

And I agree with the other kittens, this looks very similar to the schematics of the Oric MIDI/Minitel board posted by Iss.
Now who has a MIDI compatible keyboard? ;)

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