Analogue-sequencer

Hi Chiel,

> the screen keeps showing 
> "??/8 ?? iuéiPlay" or a variation on that on the first line and "bank 
> FTS tune" on the second line, and the 16 'step' LEDs are 
> G,A,G,A,G,A,A,A,G,A,G,A,G,A,A,A (G=green A=amber). i then found out 
> that in my enthusiasm to try it i'd forgotten to place the backup 
> battery, so i put that in and tried again; same thing. next i tried 
> the F1+7 reset thing, to no effect. 
> i then thought it might be a firmware problem so i DL'ed the .syx 
> (not the beta) file and uploaded that to the machine, which it 
> accepted no problem, no problems with the func+page button 
> combination thing to get into firmware mode either, but then after 
> the file has been uploaded to the P3 it's the same thing with the 
> weird lEDs and freaky txt in the display...
> any ideas what the problem could be?

Sounds to me like it could be a RAM problem.
The CPU in the P3 has 1k of built-in SRAM, and the mainboard has 64k.
The firmware check and upload code starts in internal RAM mode so that
the sequence data in external RAM is not over-written during firmware
update.
Since your firmware check is OK, and the update worked, but it is
showing garbage in the main program, the likely cause is that it has
switched to external RAM that doesn't work.
Since the LCD and LEDs are working, this suggests the CPU and the
interface circuitry are OK - the LCD will not work without 2 way
communication with the CPU, and it is showing the right things where
they are being read from code memory.

Did you get the memory organisation menu appearing - the one that says
"3x16  6x8  12x4" ?
Your LCD is showing "??/8 ?? iuéiPlay".
The first part "??/8" shows the current bank number, and the total
number of banks.
?? indicates an out of range value, and "8" is not a valid number of
banks - it must be 3, 6 or 12.
These values would be forced to sensible values at boot, so the fact
that they are wrong suggests an external RAM failure.
The second ?? shows an FTS root note that is out of range, and the
'iuéi' bit should be the short FTS name - the corruption here shows that
the pointer to the string (which is held in code memory) is not pointing
to the right place.
Again, these values are validated at boot, so this also suggests bad
RAM.

Can you check the 62256 RAMs are oriented the right way, and that they
are being supplied with power from the BBRAM controller chip.
Also check the 74HC138 decoder, and 74HC573 latch in the address
de-multiplexer.

Let me know how you get on.
I've got my fingers crossed for you !

Cheers,
Colin f