Yamaha data cartridges

[Davo]

I asked this on rec.music.makers.synth, but nobody seemed to be able to help.  In the manual for the Yamaha TX802 (rackmounted version of a DX7mk2), it says that the RAM4 data cartridge contains one bank of memory and that in the future there may be cartridges with as many as 16 banks.  Does anyone here have the schematics of the RAM4 data cartridge or know how to make this legendary 16-bank cartridge?

[DrBunsen]

How hard could it be to reverse engineer these old carts?  The Roland ones go for about $60 for 64k of storage.  That's just ridiculous.  I'd be highly tempted to buy one, clone it and release a freeware rebuild plan based on modern parts.  If I had a clue about stuff like that :)

[moebius]

How hard could it be to reverse engineer these old carts?  The Roland ones go for about $60 for 64k of storage.  That's just ridiculous.  I'd be highly tempted to buy one, clone it and release a freeware rebuild plan based on modern parts.  If I had a clue about stuff like that :)

Well - I popped open the 16k one, MC-16C. Only "special" thing is the Roland made card edge connector. Tracing this wouldn't be that hard. (SRAM chip is TC5517APL)

Moebius

[DrBunsen]

So it's basically a giant BankStick?  ;D

Any chance you scanned the board and kept the image somewhere?

[Jidis]

I popped open the 16k one, MC-16C

Moebius,

Thanks for that effort. :)

I think that's the same one I've got on my controller keyboard, and I can't stand it. It's clunky and sticks up out of the panel, keeping you from setting drum machines or anything on it. ;D

I usually keep it out, but the stupid keyboard defaults to some "split" dual channel mode or something, so I have to make a couple settings whenever I use it. I wanted to see what was in that cart a while back, and maybe install one inside the Roland instead. I never really have more than one patch (or two) in it.

Was that the only thing in it? I didn't see a datasheet for that, just those sleazy links to people trying to sell me the specs.

Thanks!

George 

[moebius]

DrBunsen: It's based on SRAM - I don't think it really needs the specific chip ect.

Jidis: It's my pleasure! 2 Screws ect - and I just like to see "what's inside". It's double sided PCB inside with TC5517APL, 2 SIP resistor packs (9pin for pull-up or down, next to SRAM on both sides), a battery, a diode and a resistor, 2 probably trasistors for memory protection switching and the switch. No pictures - I would provide those as needed if I had a digicam.

Easy to trace, "clone", whatever.. just if I had a slave driver...

Moebius

[DrBunsen]

I just joined the TR-707 yahoogroup, and they have the schems for the M-64C in their Files page.

[bill]

I just joined the TR-707 yahoogroup, and they have the schems for the M-64C in their Files page.

Please could you download and link that file ?

Thanks !!

[DrBunsen]

/edit/ ok that didn't work, I'll try and add it to the wiki somehow.  Link when I manage it.  Meanwhile I can only suggest joining the yahoogroup and pulling the file yourself.

[DrBunsen]

If anyone wants it PM me with your real email address.