MPC 4000 CPU's

I'm not in the business of convincing a business in the business of repairs to enjoin my business in business. heh heh.... wow.... phew

They seem to think it is not possible.

I'm quite suprised because I'm 99% sure it IS possible.

I think the problem on their end is the manner in which the Microprocessor is installed. It requires destructive modification, and they don't want to be destructively modifying peoples hardware.

These circuit boards are no longer in production, so the only option is to modify them for a repair.

Pretty straight forward though, I'm suprised they have not undertaken this themselves.

BTW, I did ask them to sell me one cheap, and again, they will, but won't confirm what the problem is. It could be many things and I don't want to get one that needs a different IC replaced and flashed, as I don't have the hardware or the proprietary firmware to do so. And I'm sure as hell not gonna replace the CPU, and have to send it to them to replace and flash a different component, thereby showing them how to do it. That would be foolish.

how much does a working board cost?

they are no longer manufactured. no source I am aware of and I don't anticipate their ever will be.

I know VST had a few, like 4, about 6 months ago, I'm sure they are all gone, and they were over $400, if I remember right they may have been $600

Besides sample processing, I wonder how to benefit from a
faster cpu. Sure, it's always nice to have a fast response,
but waiting some seconds under the SAMPLE EDIT page
never annoyed me.

Generally, the idea of running an "old" OS on a newer machine
sounds good, like running DOS on a Pentium machine, but in
case of the 4K, I simply don't see that demand for more speed.
It only would be a nice solution for defect boards.

TSR

I concur with tsr

The initial idea WAS for a repair for defective units. Upon research I found compatible, faster chips.

There WOULD be a benefit in speed. Dramatic? Maybe yes maybe no. But a benefit nonetheless.

Of course there is more at play than just the CPU, such as the 'bus', (Other components) and RAM speed.

However, RAM is dirt cheap for these, and I think faster RAM and a faster CPU may increase things quite a bit,
but again it depends on more than just that.

At any rate, I'm still gonna move forward if for no other reason than when mine goes I want a fix. And maybe a 'soup'.

This is an interesting idea -- especially for repairing a bad board -- but how often is it that the CPU goes bad instead of some other component on the board?

Not all microprocessors are interchangeable. They're a different beast entirely than PC CPUs. Usually a system is designed around a particular microcontroller not vice versa.

I've worked on some projects using PIC microcontrollers (which are about as basic as they come) and even microcontrollers in the same family are rarely compatible. Even if they seem to be pin compatible -- there's usually some obscure footnote in the datasheet that says so which you only discover after hours of "WTF why isn't this working right?"

In my opinion, I doubt that Akai put much margin in the design to allow for upgrades... but you never know until you try.I do commend you on the effort and idea. Good luck!

The idea was really not as an upgrade, but mainly a fix.

I just thought it was interesting, after all the reading of various white papers and data sheets, that there was more than one in the 'family'.

Usually this is due to changes. Usually a change that will make it non-compatible with it's older brother, but it appears there may be at least one faster chip, so why not try.... If that don't fly, I'll throw the original in.

The MP/CPU is very common to burn up in these I guess.... and nobody will replace them.

I've had some discussion with VST recently... might be able to get my hands on a donor

If there is a faster chip then it's definitely worth trying.

I think most 4k users would agree with this.

LvngDead wrote:If there is a faster chip then it's definitely worth trying.

I think most 4k users would agree with this.

Actually, Most with technical knowledge are somewhat upposed, even myself, as I realize the potential issues, but again, we're not gonna know until I can test it.

If it works with the faster chip great, if not, just a replacement/repair is gonna be a great thing to have around.

Especially if I can get it socket mounted

<Been away for a while, hi.>

There's something bad wrong here. Intel doesn't make a Sharc -- that's an Analog Devices product. It is a DSP and not at all the same as the ARM-based CPU that is used in the MPC. Intel made a variant on the BlackFin for a while (also an AD product), but that is also unrelated to the CPU used in the MPC4000. AFAIK, Marvell Semiconductor has taken over Intel's ARM-based CPU line.

You won't find a current CPU that is pin-compatible with the CPU in the MPC4000. Nobody maintains pin compatibility over a decade in CPUs. There's no benefit because if you are upgrading CPUs, there is so much else that needs to be upgraded on the board anyway (memory interfaces, etc.) that you don't save any effort. The newer CPUs are *software* compatible with the old ones.

If you did find one, soldering it would be a nightmare, but that's the very least of your worries.

All of this effort would buy you exactly nothing unless the OS were upgraded to take advantage of it of course. There would be exactly no benefit whatsoever for an MPC running the original Akai OS.

Good luck,

-illiac

I guess there is no way of getting a different mainboard to run in the machine?

Maybe there might be one similar?

mr_debauch wrote:I guess there is no way of getting a different mainboard to run in the machine?

Maybe there might be one similar?

You might be thinking that the main board of the MCP4K is just an ordinary computer motherboard. But it's not that at all. It has quite a lot of specialized logic, in the form of gate arrays and what not, for handling stuff like MIDI event timing, audio clocking, and so on. It's a one-of-a-kind thingamabob. There's a schematic of it running around somewhere; I used to have a copy once upon a time.

The most important point, though, is this:

Changing the processor will change nothing about the user experience unless the operating system is changed to take advantage of the new processor. Akai/Numark won't even fix well-documented bugs in the existing OS for the existing processor and board. It's completely unrealistic to think that they will be involved in any effort to upgrade anything on the MPC4K.

My guess is that whoever swiped (err, borrowed) the code that made the JJ OS possible did not "borrow" the MPC4K code also. If they had, it would probably already have come to light by now.

-illiac

illiac wrote:

mr_debauch wrote:I guess there is no way of getting a different mainboard to run in the machine?

Maybe there might be one similar?

You might be thinking that the main board of the MCP4K is just an ordinary computer motherboard. But it's not that at all. It has quite a lot of specialized logic, in the form of gate arrays and what not, for handling stuff like MIDI event timing, audio clocking, and so on. It's a one-of-a-kind thingamabob. There's a schematic of it running around somewhere; I used to have a copy once upon a time.

The most important point, though, is this:

Changing the processor will change nothing about the user experience unless the operating system is changed to take advantage of the new processor. Akai/Numark won't even fix well-documented bugs in the existing OS for the existing processor and board. It's completely unrealistic to think that they will be involved in any effort to upgrade anything on the MPC4K.

My guess is that whoever swiped (err, borrowed) the code that made the JJ OS possible did not "borrow" the MPC4K code also. If they had, it would probably already have come to light by now.

-illiac

I didn't figure that it was the same... but maybe there is some sort of way to find out who pressed the board and maybe we could find out if anything else used it? not necessarily a computer... maybe even one of the z-seried samplers. who knows... but now that you mention it... it is true that most of the stuff would be intergrated onto the one panel.

mr_debauch wrote:I didn't figure that it was the same... but maybe there is some sort of way to find out who pressed the board and maybe we could find out if anything else used it? not necessarily a computer... maybe even one of the z-seried samplers. who knows... but now that you mention it... it is true that most of the stuff would be intergrated onto the one panel.

It doesn't really matter who fabricated the PCBs. In electronics, the customer (Akai) designs the layout and sends it to a fab house for them to create it. The fab house only makes what they're told to make. These CPU boards are custom made for the MPC 4000. There may be other parts inside that are interchangeable with other MPCS but not the CPU board.