Custom-built multi-bank Roland M-256/M-512 memory cards

[gj67]

Received my cards today Although It's a good thing us Dutch have our own version of Santa clause as I already got myself a D-05 for Christmas (quickly running out of holidays/excuses).

Fitment in the Roland D-70 is spot on, fits fine without any issues. Formatted the RAM card, copied the internal sounds to the card, tested the sounds: We're all good

Next hack/idea is to see if I can copy the contents of a PCM card to the RAM card and thus emulate a sounds rom card.

Thanks Joachim for sticking in there and bringing this card to final production.

[ʝɵʝɵ]

Glad to hear that everything is working fine! I just added the D-70 to the compatibility list. Too bad that the D-05 doesn't take any M-256 cards, eh?
Since PCM cards typically require more storage, I guess you'd have to reconfigure the card to 4M to properly take advantage of that - if it's going to work. dojoe will soon write up the information on how the card can be reconfigured, also useful in case you decided that you need a M-512 instead of a M-256 or vice versa.

[baz99]

Roland PCM cards (at least the ones for the JV series) are physically incompatible, they are much shorter and have a different connector so there is no way you can use to existing card as a PCM card.
Also how would you copy anything on it?

[ʝɵʝɵ]

I do think that some of the cards have an identical form factor - at least the ones for the U-220 look identical to me and the M-256 card fits perfectly into the PCM ROM card slot of the U-220.
Copying data would have to be done using a custom writer hardware of course, which has been discussed somewhere deep inside this thread. Naturally this is not a use case we can support, you're on your own if you want to try that.

[dojoe]

Received my cards today Although It's a good thing us Dutch have our own version of Santa clause as I already got myself a D-05 for Christmas (quickly running out of holidays/excuses).

Fitment in the Roland D-70 is spot on, fits fine without any issues. Formatted the RAM card, copied the internal sounds to the card, tested the sounds: We're all good

Woo, those photos make me super proud -- seeing your final product in use is a great feeling, really lifts the spirit! Thank you for the photos =D

Next hack/idea is to see if I can copy the contents of a PCM card to the RAM card and thus emulate a sounds rom card.

As jojo said, you'll need a custom reader/writer I'm afraid. It's been discussed somewhere in here and is certainly doable (my test jig actually has generic reader/writer functionality), but making it customer-friendly is another story. The hardest part would be sourcing a fitting card connector - or building your own using a 3D printer.

As for compatible cards, both jojo and baz99 are correct in that there are PCM cards out there with an incompatible connector, but there are also ones with the same connector as the RAM cards -- up to 4M are possible, and my card can be configured to any bank size between 256K and 4M.

[gj67]

Well, there is another use case for emulating PCM cards (btw, I checked and the D70/U series cards are the same size as the ram cards) as it can also be used to create your own pcm cards with custom sounds as well.

Yes, you can also get a sampler (I have two) but sometimes I like doing things just because it can be done, not necessarily because it might make sense. And the advantage of having the sounds in the synthesizer is you can actually use the native synth engine to build new sounds from it.

I have an extra D70 I use for spares so getting the connector is easy enough but I actually had a better idea for rev 2.0 of the card What if you would add an I/O controller and micro usb connector? So you could directly load/save data from the card?

Cheers,
GJ.

[ʝɵʝɵ]

dojoe will publish the sources for the card soon so you can build your own improvements; but you can rest assured that we will not make any more modifications to the card apart from possible bugfixes for currently unsupported devices. Adding any kind of USB interface or such is completely out of the scope of the project. Given how tight the card slot already is, you would most likely have to extend the card length quite a bit to even fit a USB connector onto it, it's all but a trivial modification!

[dojoe]

I guess that's why GJ said 2.0 But yeah, not going to happen

Some elaboration: Instead of just a simple SRAM(-ish) chip behind some voltage level translators which the card is now, I would have to add a microcontroller with USB support, arbitration/multiplexing between the micro and the synth, find a spot for the USB jack, write firmware... It would be a tremendous effort, have no end of subtle bugs and be pretty expensive.

I'd much rather build a separate reader/writer hardware. You need only one of those after all.

[dojoe]

The post office will have a field day!

37 envelopes with MRAM cards, complete with shipping labels, stamps, customs declarations (if needed), the whole shebang. Enough for me to know I will never pursue a career in the fulfillment business

[SoundWerx]

Massive effort. This has cost you way more than what you are charging when you add up the time you've spent helping everyone out. If you set up a donation page I will buy you a coffee (or a beer ). I'd be happy to. Thanks again!

[gj67]

I guess that's why GJ said 2.0 But yeah, not going to happen

Some elaboration: Instead of just a simple SRAM(-ish) chip behind some voltage level translators which the card is now, I would have to add a microcontroller with USB support, arbitration/multiplexing between the micro and the synth, find a spot for the USB jack, write firmware... It would be a tremendous effort, have no end of subtle bugs and be pretty expensive.

I'd much rather build a separate reader/writer hardware. You need only one of those after all.

Absolutely understand it and I'm quite happy with the card as it is. Like I said, I already have the connectors from a scrap D70 so I just need to add a USB I/O controller which I can hook up to my Mac or laptop. Then again, I have little spare time as it is so this won't happen anytime soon.

Cheers,
GJ.

[ʝɵʝɵ]

You might not even need to go the complicated route via USB. Maybe one of those small popular dev boards with plenty of GPIO pins and an SD card slot could be used to program the card by connecting the GPIO pins to the D70 card reader and directly talking to the MRAM chips that way. You could simply copy the memory files from the SD card that way.

[dojoe]

And for reference, the card pinout on http://www.vintagebox.de/elek/elekd50card.html#p2 is correct, even if the physical dimensions they mention are bogus Let me copy that here:

1	2..19	20	21	22	23	24..31	32*	33	34
+5V	A0..A17	MR	WE#	CE	OE#	D0..D7	GND	VBAT	PD

*Pin 32 (GND) is the slightly longer one.

A0..A17 is the address bus (card input only)
D0..D7 is the data bus (bidirectional)
WE#, CE and OE# are standard SRAM Write Enable, Chip Enable and Output Enable signals (WE# and OE# are active-low, CE is active-high).

MR is the write protect switch - connect to 5V for write OK, to GND for write protect. This is just an indication to the synth, it can still overwrite the card if it decides to - the write protection is implemented purely in software.
On 4M PCM cards, this pin is repurposed for A18.

VBAT carries the battery voltage (nominal 3V for a good battery). I connected it to the 3.3V rail via a resistor to keep the synth from whining about low battery. Do add the resistor - the Akai MX1000 likes to pull a lot of current from this if I connect it directly to 3.3V, I suspect a clamping diode in the Akai.

PD is Presence Detect, connect to +5V for the synth to detect a plugged card.

[ʝɵʝɵ]

I just checked and the vintagebox site has actually been updated in the meantime with correct physical dimensions. Maybe the author is reading along here, or had to build another card and noticed that the old measurements were incorrect.

[Mesmerised]

Thank you guys for this great project! Working fine here (D-50, D-110, JV-1080).