By motosega
Wed Aug 06, 2014 1:06 pm
since we will never have access to the akai sourcecode for the mpc 500, i was thinking about some other way of hacking it.
looking at the mpc500 service manual, there are two interesting connectors on the circuit diagram.
first there is the big 50 pin connector in the battery compartment, which is labeled E4M (my guess is that this is for an in circuit emulator) and also the debug port.
looking over the dev tools for the sh7727 i see that there is an onchip debugger.
which seems to be fuly documented. the debugger supports reading out the internal memory, looking at the conents of memory adresses, and writing to memory.
the concept is fairly simple, remember the old days on 8 bit computers like the c64 you could cheat by interupting the prgram with "break" then find the memory location where your lives were stored, then use "poke" to change the number of lives. also think the actionreplay cart for things like playstations.
well..... my thinking is that it is completely possible to construct a device that can connect to the debug port, and change the contents of memory locations in the mpc500.
this may not sound like much but, but i'm thinking that it could be used to add a real mixer to the 500, after all, each pad in a program has a volume, and an eq. the fx sends are doable too.
it should be entirely possible to do all this on a small pcb that fits in the back of the mpc. connects to the midi ports and debug port and lets you controll the mixer via midi. once the hard work is done, we're talking a diyable board that would cost about 40€ to make
getting hold of sh7727 debug tools probably isn't going to be cheap or easy.
building an arduino based debug tool is probably at the limit my technical ability if i study the manuals for a long time...
and the real stcking point is that the debug mode probably halts the mpcs operating system while it is running. so realtime changes while the mpc is playing might not be possible without the audio skipping. but it'd still be really worthwhile.
if i make any real progress on this i'll have some results this winter. but i think it would be a much simpler task for somebody with real embeded systems experience, me, i just dabble in stuff like this, i have built various midi and dmx devices with arduinos, but i'm no expert.
i'm posting this here, not as a promise that i'll ever get this done, and not specificly looking for help. but to give a heads up to future googlers that there is indeed a realistic way to add features to the mpc500, and if somebody with the apropriate skills gets around to this before i do, i'll be first in line to buy a pcb.
ewan.
looking at the mpc500 service manual, there are two interesting connectors on the circuit diagram.
first there is the big 50 pin connector in the battery compartment, which is labeled E4M (my guess is that this is for an in circuit emulator) and also the debug port.
looking over the dev tools for the sh7727 i see that there is an onchip debugger.
which seems to be fuly documented. the debugger supports reading out the internal memory, looking at the conents of memory adresses, and writing to memory.
the concept is fairly simple, remember the old days on 8 bit computers like the c64 you could cheat by interupting the prgram with "break" then find the memory location where your lives were stored, then use "poke" to change the number of lives. also think the actionreplay cart for things like playstations.
well..... my thinking is that it is completely possible to construct a device that can connect to the debug port, and change the contents of memory locations in the mpc500.
this may not sound like much but, but i'm thinking that it could be used to add a real mixer to the 500, after all, each pad in a program has a volume, and an eq. the fx sends are doable too.
it should be entirely possible to do all this on a small pcb that fits in the back of the mpc. connects to the midi ports and debug port and lets you controll the mixer via midi. once the hard work is done, we're talking a diyable board that would cost about 40€ to make
getting hold of sh7727 debug tools probably isn't going to be cheap or easy.
building an arduino based debug tool is probably at the limit my technical ability if i study the manuals for a long time...
and the real stcking point is that the debug mode probably halts the mpcs operating system while it is running. so realtime changes while the mpc is playing might not be possible without the audio skipping. but it'd still be really worthwhile.
if i make any real progress on this i'll have some results this winter. but i think it would be a much simpler task for somebody with real embeded systems experience, me, i just dabble in stuff like this, i have built various midi and dmx devices with arduinos, but i'm no expert.
i'm posting this here, not as a promise that i'll ever get this done, and not specificly looking for help. but to give a heads up to future googlers that there is indeed a realistic way to add features to the mpc500, and if somebody with the apropriate skills gets around to this before i do, i'll be first in line to buy a pcb.
ewan.
