roland-mram-card
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dojoe
Quirks For Roland U-20 Owners (And Possibly Other Synths)
#1) When using this with the Roland U-20 and inserting a freshly built card for the first time, the error message "RAM Card Verify Error!" appears and continuing on to format the card is not possible. This is solved by removing the card and changing both BANK switches to the far right to select the very last bank (D-4). After doing that and re-inserting the card, the desired message appears and says, "It's a New RAM Card. Initialize it? [ ENTER ]". All other banks are able to properly initialize from that point on
#2) With the U-20, an informational message appears every time the card is inserted and a properly formatted bank is selected. It says, "RAM Card Battery Low!". However, this is expected behavior because there is no battery on the new MRAM card. This is just a leftover from the old technology and it does not affect operation of the new MRAM card in any way
Point 1) seems strange - from the synths' perspective, all 16 cards should be filled with garbage when inserted for the first time, and the synth cannot tell those 16 cards apart (i.e. there is no reason why D4 should work while A1 shouldn't). The error message you got initially could hint at the card not being inserted properly, and using the bank select switches might have moved the card in the slot just enough that the synth could read it properly again. I also have this with my D-50 sometimes, and just moving the card around a bit in the slot solves the issue (but in my case I suspect the problem is due to the slot being a bit damaged from very early memory card experiments, so most other owners shouldn't see this issue with the D-50).
Regarding point 2), just to avoid confusion - our card does report a battery voltage to the synth. So the behaviour is not exactly "expected". However, the voltage is 3.3V (like what's expected by the memory chip) rather than the typical 3V provided by a coin cell battery at most. We suspect that some synths cannot handle this extra 0.3V in their calculations of the battery state and end up with a wrong result and thus showing a warning. As far as we're aware, only the U-20, JV-1080 and JV-2080 have this problem, and it's mentioned in the FAQ section of the manual.
Thanks for clearing this up. Your explanation about Point-1 makes perfect sense so... not an issue. re: Point-2, Ooops! I overlooked that part in the manual.
I got my hands on a U-20 temporarily and interestingly, I don't see the second issue here, i.e. no "low battery" warning. Maybe it depends on the manufacturing date or firmware version whether this problem is exposed. Can you confirm the OS version of your U-20? To do so, press PART and RHYTHM simultaneously to enter demo mode, then press MARK, JUMP and ENTER simultaneously to enter test mode. You should now see the OS version. Mine is V2.00 (89/06/16 1323). According to the serial number, it was manufactured in November 1989.
Edit: After entering test mode, press JUMP and BANK 4 simultaneously. You should now see the battery voltage as reported by the memory card. It's 3.2V for me.
> Can you confirm the OS version of your U-20?
I tried it again today and when I insert the card I no longer get a "RAM Card Battery Low!" message. The only thing different I can think of is that before, only three banks contained actual U-20 Patch data. The remaining 13 banks were only initialzed and formatted (for use with the U-20). Today, all 16 banks are initialzed, formatted and contain U-20 Patch data.
My U-20 is V3.03 (89/10/30 1400) Manufactured September 1991
Test Mode 4 R/W:OK RAM Card Bat:3.3V
Very interesting! It should definitely not depend on how many banks are initialized - the synth only sees a single bank at a time, and its contents do not change anything about the reported voltage. The only reason I could imagine why you had the problem once but not now is a power supply issue or anything else causing a fluctuation in power delivery. So the mystery remains for now...