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

[dojoe]

Hah, yeah, the 16A won't do you much good The D-50 uses 256kbit, i.e. 32kbyte, so that's A0 thru A14. Our card uses a 4mbit chip and supplies A15 thru A18 from the slide switches. Note that ordering the address bits in this way is not really necessary - you can freely rearrange address bits as you please if it simplifies PCB routing. The MRAM isn't going to care where those bytes are stored after all

The edge connector actually supports up to 19 address bits (the MR signal is used for A18 on some PCM ROM cards) and I've built jumpers onto the card that will switch A15 thru A18 between the slide switches and the edge connector, allowing any configuration between 16 banks of 256kbit and one bank of 4mbit. We only ship the 16x256 and 8x512 variants since that's the only RAM card sizes used by synths, but I have deliberately made the card hackable that way if anyone wants to dabble in custom PCM cards

[Avro_Arrow]

Thank you dojoe for all your help and insight.

I'm going to go with a static ram with battery and MXD1210 (or similar).
I'm just going to use dip switches for the extra address lines.
This way I can just stick with the 5 volt logic and not have to
convert to 3v3 data lines. I'm a wimp, I know. Its also dirt cheap.
I can live with changing the battery every five years.

Thanks again!
James

[dojoe]

I'm a wimp, I know.

But you also opt out of a buttload of headaches

Good luck with your project, let us know how it goes!

[Avro_Arrow]

I'm a wimp, I know.

But you also opt out of a buttload of headaches

Good luck with your project, let us know how it goes!

Thanks, I will!

[ʝɵʝɵ]

We are out of stock!
It took a bit longer this time due to the registration form mishap, but the last cards are now finally sold. However, there might be another batch coming (definitely not before the second half of 2020, maybe even later), so you can sign up at https://sagamusix.de/other/roland_memory_cards/ to be notified when the next batch is ready. (this time the registration form will hopefully not break after a month )

[glengood87]

Hi all,

I have sold all my Roland synths and so no longer need my card - please PM if anyone is looking for one. I am based in Adelaide Australia, but can post worldwide.

[ʝɵʝɵ]

On Gearslutz someone was recently asking for one:
https://www.gearslutz.com/board/showpos ... stcount=14

Also here but a few months ago:
https://www.gearslutz.com/board/showpos ... tcount=321

[RDP]

I am also looking for one. glengood87 cannot be PM'ed so I guess I am looking for any leads before signing up for the main list.

thanks,
RDP

[ʝɵʝɵ]

Signing up to our list doesn't mean that you commit to any purchase; you will simply be notified when the cards will be available. So there is nothing wrong with signing up and still looking for someone else selling their card at the same time.

[rd3d2]

Just found your site = what an amazing project! Such a shame that you have no stock though.
Are you aware of anywhere else doing this (seems like a dead cert for someone in Shenzhen?!)

[ʝɵʝɵ]

Just found your site = what an amazing project! Such a shame that you have no stock though.
Are you aware of anywhere else doing this (seems like a dead cert for someone in Shenzhen?!)

Yes, there are definitely other people exploring this space, but so far noone else is making M256/M512 replacements. There are some Yamaha card remakes that were already linked in this thread, and not too long ago I saw another Roland memory card remake (also based on MRAM) that was sold commercially via Thomann. However, I cannot find it in the Thomann store anymore, not sure what's going on there. That memory card was considerably more expensive than ours, but also offered more memory banks.

Edit: This is the one, it's a Roland M-16C / M-64C replacement: https://shop.waverex.de/en/mc-256-memor ... vices.html

[madtheory]

Edit: This is the one, it's a Roland M-16C / M-64C replacement: https://shop.waverex.de/en/mc-256-memor ... vices.html

Wow very expensive but it does come in a very nice box with cool switches, which straight off prevents it from working on Akai devices.

[ʝɵʝɵ]

So Akai also used the M16C/M64C format in their synths?

[madtheory]

Oops, I thought it was an M-256 replacement my bad.

[ʝɵʝɵ]

And to be fair:
- Their cartridge must be containing a much bigger MRAM chip, holding 256 banks (assuming M64C is 8KB, that would be a 2MB MRAM chip compared to our 512KB). The MRAM chip is the single most expensive component in our design, so it must be a big factor in their pricing as well.
- The margins on our memory card are minimal. If we wanted to run a company like WaveReX with our cards in a profitable way, they would have to be priced well above 100 Euros as well, I'm sure.