MPC 2000XL EPROM

Hello!

This is my first post here. I have tried to search for the answers, but either have not found any or the answer was "use search"

I suspect the flash rom might gone bad in my MPC. It is stuck on "Wait......." and sometimes goes into "Detecting memory". When I try to reinstall the OS, it goes into an endless loop - it reads the floppy for a second and then says "Insert MPC2000XL disk!". I tried different floppy drives, but it is mostly the same effect. With one floppy if I didn't insert the disk, I would get a debug screen crash.
So I would like to exclude that maybe the OS is bad. I've seen that you can buy such ROM, but since I have the tools and chips I thought it's a good opportunity to try it myself.

I understand I should burn the MPC2KXL.bin file into 27512 IC and then follow the restore procedure?

Are there other things to try before I do this? I already tried different memories, different configurations, no ram, disconnected any expansions etc. I have not tried to run it off SCSI, but I am waiting for a suitable cable.

Thank you!

I meant 27C040 instead of 27512.

That .bin file you're talking about is what people copy to a floppy to upgrade / downgrade the on board intel flash.

Copy that file to the floppy, hold REC & OVER DUB buttons down and turn on the MPC. As long as the initial bootrom is functional, the MPC will read the .bin file off the disk and load it in to system memory. From there, you can go to load and reflash the MPC from the bin on the floppy disk.

You are correct that there is a separate ROM available which is said to be a recovery ROM, where you'd set the dip pins on the mainboard to tell the MPC to boot off of the ROM/EPROM instead of the onboard flash - by which you'd be able to do what I said above with the disk method.

There are two 2-pin jumpers connections on the main motherboard under where the 8-outs usually sits. the Jumper(s) has to be in one of the 2 positions to boot up correctly.
I can't remember exactly which one but try there also.

richie wrote:Copy that file to the floppy, hold REC & OVER DUB buttons down and turn on the MPC. As long as the initial bootrom is functional, the MPC will read the .bin file off the disk and load it in to system memory. From there, you can go to load and reflash the MPC from the bin on the floppy disk.

You are correct that there is a separate ROM available which is said to be a recovery ROM, where you'd set the dip pins on the mainboard to tell the MPC to boot off of the ROM/EPROM instead of the onboard flash - by which you'd be able to do what I said above with the disk method.

The problem I have is that when I do REC & OVER DUB, it will read the disk drive for a second, then show "AKAI MPC 2000XL BOOT ROM V1.0" (or very similar) and then shortly after it will show "INSERT AKAI MPC 2000XL DISK !". After a second or so it will read the disk drive again showing the boot rom message and then insert disk message. It will loop like this forever. It tried different floppy cables and drives to the same effect.

I was looking at motherboard schematic and there is "232C" header that I understand may be used to read logs whilst the machine is running. However, I cannot find this header anywhere on the mother board, so maybe it doesn't have its pins soldered in. The another idea I have is to solder a wire to the TX cpu pin and connect and another to ground and connect to the UART dongle to see if there are any debug messages being sent. Maybe there could be information about the potential fault.

JUKE 179r wrote:There are two 2-pin jumpers connections on the main motherboard under where the 8-outs usually sits. the Jumper(s) has to be in one of the 2 positions to boot up correctly.
I can't remember exactly which one but try there also.

Thank you! I checked the jumpers, and they are in correct positions.

elcct wrote:
The problem I have is that when I do REC & OVER DUB, it will read the disk drive for a second, then show "AKAI MPC 2000XL BOOT ROM V1.0" (or very similar) and then shortly after it will show "INSERT AKAI MPC 2000XL DISK !". After a second or so it will read the disk drive again showing the boot rom message and then insert disk message. It will loop like this forever. It tried different floppy cables and drives to the same effect.

The fact you see that means that the BOOT ROM partition is functioning as it should as you did say that you see it attempting to read the disk.

Why it isn't reading the disk points to an issue of the drive.

I tested it with two floppy drives and one I am 99% sure is working. I have ordered a NOS drive to be sure.

elcct wrote:I tested it with two floppy drives and one I am 99% sure is working. I have ordered a NOS drive to be sure.

Read your private messages.

richie wrote:

elcct wrote:I tested it with two floppy drives and one I am 99% sure is working. I have ordered a NOS drive to be sure.

Read your private messages.

It says "This message was deleted by its author."

elcct wrote:It says "This message was deleted by its author."

Must've been when I was trying to clear out my mailbox as it was full. I'll send you a message again.

So I flashed appropriate IC, the MPC has recognised the chip and booted off of it, but still got the same "Wait......." message.

I have tried few more times to also reload the OS from a floppy drive and once out of many tries the floppy picked up and loaded the OS from disk, however when the system started I immediately got the same "Wait......." message.

Just to update. I ended up getting a new motherboard and my MPC now works fine.