MIDI Interface

[Lord Thag]

I'd be interested as well, as long as I could plug a keyboard into the Atari to play

[ivop]

I'm having trouble getting Midi Maze to run on the Atari 1040STE. Booting the .stx file(s) (both versions in the TOSEC torrent) of my Gotek drive with HxC firmware, does not work. After converting them to HFE, they boot, but when I start the program, I get TOS Error #35 ?!?

 

Does anyone have a working disk image for the Gotek drive? Or perhaps it doesn't run on an STE, which was not available yet in '87?

[ivop]

I decided to build a second prototype (finally received the DIN5 sockets) and a second external clock and I stumbled upon a problem regarding the clock generator. Sometimes (like 1 in 10) it starts oscillating at the 3rd overtone, resulting in a clock three times too high. So I tried a different series resonant oscillator circuit, which works a lot better. Now I have to build a second one of that circuit so I can test Midi Maze with two 800XLs

 

On a similar note, I am thinking about replacing the whole series resonant oscillator circuit with a single package oscillator. That would reduce the component count tremendously and I don't have to worry about the tuning of this circuit anymore.

[+mytek]

ivop,

 

Since you are still in the development stage, I was wondering if you could match the same pin-out on the 1088XEL SIO-AUX connector which currently is compatible with Lotharek's SIO2SD and Dropcheck's new SDriveXEL board. That Interface uses a 5 pin latched connector, but with the addition of a 6th pin, I have added the Motor Control Signal. However to stay true to the original purpose, it will still retain the 5-pin latched version of a 0.1" pitch header, simply adding a lone 6th pin at the same pitch spacing. This way the stock cabling and connector for the original purpose still works without modifications, but if you use a 6 position connector, it'll work for your MIDI board instead. Obviously even without changing your current pin assignments this scheme will work, but to prevent errors, it's best if the pin assignments are the same on both ends. Please give this some thought, and no hard feelings if you wish to leave things as they are.

 

 

- Michael

[Kyle22]

Internal with MIDI In, Out, Thru on the back panel?

 

 

Edit: got the smiley wrong.

Edited September 29, 2017 by Kyle22

[+mytek]

Internal with MIDI In, Out, Thru on the back panel?

 

 

Edit: got the smiley wrong.

Yep I figured some people might like that. Actually that reminds me of something else... might be nice to have some mounting holes for a couple of threaded right angle brackets to go. Make it easier for panel mounting.

 

Oops I see ivop already thought of that.

 

- Michael

Edited September 29, 2017 by mytekcontrols

[ivop]

Sure, I could change the order of the pins. That's no big deal. But, you also need CLOCK IN to be MIDI Mate/Max compatible. Do you think another pin would fit?

Edited September 29, 2017 by ivop

[ivop]

Changed the PCB to incorporate a single package oscillator. Also added support for 2MHZ, 4MHz or 8MHz oscillators for when one or the other is not easily available. There's a small jumper block to select the right divider. If everything goes as expected, I'll receive a few oscillators tomorrow, so I can test this new design.

Edited September 29, 2017 by ivop

[ivop]

@mytekcontrols, here's my new SIO connector layout. Does this suffice?

 

[+mytek]

@mytekcontrols, here's my new SIO connector layout. Does this suffice?

 

midisioconn.png

Yes I think I can fit in the additional pin for CLOCK-IN which I'm assuming you're referring to the one on SIO, but probably not enough room for the extra ground pin which appears to be redundant anyway. I'll work on this over the weekend and report back in.

 

Thanks so much for being receptive to this idea. BTW, you can put me on your list to buy one of your boards when the pre-order starts.

 

- Michael

[ivop]

Yes, CLOCK-IN is the SIO CLOCK-IN input which drives Pokey at more or less exactly 31250 baud. As for the extra ground pin, it is indeed not necessary, but I included it anyway. In your case you can just ignore it. If one is to solder/jumper a SIO cable to it, the wire is already there and some redundancy is not going to hurt imho.

[ivop]

Aaah, the joy and simplicity of a single package oscillator

 

 

Left is the frequency counter: 4.0002 MHz

Right is a power supply: 4.99 v

 

[+mytek]

@mytekcontrols, here's my new SIO connector layout. Does this suffice?

 

midisioconn.png

 

Ok so now I've got the 1088XEL PCB file updated to reflect your changes...

 

Note: ivop's MIDI board doesn't require the +5 VDC (pin 1) or the COMMAND line (pin 3), so no connection will be made to those pins.

 

Pins 1-5 will use one of these latching connectors which keeps compatibility with the original SD usage.

 

 

And pins 6-7 will be picked up by a 2 pin header strip, thereby extending the header to 7 places. So when interfacing to the MIDI board you would use a 7 position Dupont female terminal housing (a non-latching connector). And if interfacing to one of the SD boards, then you would revert to the 5 position 'latched' female terminal housing. Both of these housings are based on using a crimp type terminal for the actual pin contact.

 

 

- Michael

[Lynxpro]

I'm having trouble getting Midi Maze to run on the Atari 1040STE. Booting the .stx file(s) (both versions in the TOSEC torrent) of my Gotek drive with HxC firmware, does not work. After converting them to HFE, they boot, but when I start the program, I get TOS Error #35 ?!?

 

Does anyone have a working disk image for the Gotek drive? Or perhaps it doesn't run on an STE, which was not available yet in '87?

 

 

Try AtariMania. They seem to think it'll play on an STe.

[ivop]

Try AtariMania. They seem to think it'll play on an STe.

 

I'm afraid that's the same dump. No luck getting it to run on an STE with 4MB RAM and TOS 2.06.

 

 

 

Update: I wrote some software for MIDI Mate/Max compatible devices. It's called MIDIMON and monitors everything coming in over MIDI-IN (and going out through THRU).

 

 

I included all General MIDI Controller names and all instruments of the first bank (0-127).

 

PCB sofar:

 

 

Now since there is enough room on the PCB, I'm considering adding a Wave Blaster port and audio out. There are a ton of old Wave Blaster MIDI daughterboards:

 

http://members.home.nl/c.kersten/

 

And I ordered one of these:

 

http://www.serdashop.com/waveblaster

 

Feature creep? What do you think?

[AtariNerd]

Looks quite awesome.

[ivop]

Here's the breadboarded prototype of Rev.B :

 

 

Wave Blaster port added and connected to the Dream Blaster S2 synth. Sounds wonderful IMHO!

 

Now I have to pray that everything will fit on a 10x5 board

[ivop]

It fits! Dream Blaster S2 will be positioned to the right and keeps within the boundaries of the board and has a separate analog ground plane.

 

 

Jumpers next to the clock divider are meant to select the type of crystal oscillator installed. Only one of them will be closed. Depends on which crystal oscillators are easiest/cheapest to acquire in bulk.

 

The other three jumpers (JP4-JP6) select the MIDI source used by the connected Wave Blaster daughter board. This can be either MIDI-OUT, disconnected or MIDI-IN. In the latter case, you could also use the board as a standalone MIDI sound module if you apply +5V to the appropriate pin.

 

I think this is going to be the next prototype. Probably ordering boards today or tomorrow

 

[+orpheuswaking]

What does the Waveblaster do?

[Irgendwer]

What does the Waveblaster do?

 

It's a "General Midi" wave-table board. You are able replay the sounds of it via the MIDI interface - therefore the audio out cinch ports.

Since the pin header follows a standard you could also plug e.g. a "Yamaha DB50XG" daughter board there.

 

https://en.wikipedia.org/wiki/Yamaha_XG

 

These boards are like Midi expanders without housing and internal interface etc.

Edited October 23, 2017 by Irgendwer

[venom4728a]

Wow count me in for one of these please. the Waveblaster add on looks awesome!!!

[Kyle22]

That looks great! If I had this, I wouldn't need my MT-32 taking up space.

 

Is it going to be available in a case?

[+mytek]

Looking quite nice Really loving the Waveblaster aspect. Any way I could talk you into having the Left & Right audio outputs available also from a header? Reason I ask is that the 1088XEL has provision for mixing in external audio signals through the MPBI port. It would be a relatively easy matter to connect via a set of gain setting resistors and DC blocking capacitors (probably not required if you have capacitor coupled outputs already) between the two boards, then everything would be mixed and coming out a single stereo jack.

 

- Michael

[Mathy]

Hello Ivo

 

This sounds interesting (no pun intended).

 

Sincerely

 

Mathy

[ivop]

These boards are like Midi expanders without housing and internal interface etc.

 

Thanks for explaining. It seems quite a lot of these boards were made in the nineties. http://members.home.nl/c.kersten/

 

That looks great! If I had this, I wouldn't need my MT-32 taking up space.

 

Is it going to be available in a case?

 

I would like to, but I'm not sure how to accomplish that. I have done some 3D modelling in the past (drew my whole house incl. furniture 10 years ago in SketchUp 5 or 6, just for fun), but never something for 3D printing. I'll look into it, but can't promise anything. If anybody could help on where and how to start, that would be appreciated!

 

Looking quite nice Really loving the Waveblaster aspect. Any way I could talk you into having the Left & Right audio outputs available also from a header? Reason I ask is that the 1088XEL has provision for mixing in external audio signals through the MPBI port. It would be a relatively easy matter to connect via a set of gain setting resistors and DC blocking capacitors (probably not required if you have capacitor coupled outputs already) between the two boards, then everything would be mixed and coming out a single stereo jack.

 

Yes, that would be awesome. Eventually I want to build one inside my "hacking" 800XL with ports exposed at the side and audio mixed with stereo pokey on a single 6.35mm socket, which I have already installed.

 

I'll add the pin header option for audio out. Actually, I want a pin header for the missing/mostly unused wave blaster pins, too. Not sure how many legacy cards need +12V/-12V (the Dream Blaster S2 doesn't) but I want the option to add an external power source. While I'm at it, Audio-In and TTL Midi-Out are optional, but some cards support them so at least I want them exposed so they could be used without too much hassle.