Sharing my PC-MX2 & Restoration BLOG

Hello everyone, I'm new to the forum and I recently bought a Siemens PC-MX2, along with a working control terminal and set of manuals. So I'm creating this thread to host photos of the new machine and to be a place where I can post updates on the progress of the restoration. I'm not overly superstitious, but I'm keeping my fingers crossed that the hard drive still works so I have some digital archaeology to do. Along with having the operating system intact.

Because of the upload limits I'm going to split the photos across a couple posts. These are of the outside.

Opening it up, it's remarkably clean, and looks brand new. I looked it over and tested the power circuity, and there are no obvious problems with it.

I'm not ready to tear it completely apart yet, but I decided to take a closer look at the CPU card. I noticed someone went ahead and attached some tiny heatsinks to the CPU chips.

And finally took a look at the floppy drive, and found the battery. Which of course is completely dead.

Zitat von fritzeflink

Default login is

root:siemens

admin:siemens

Thank you! I had been meaning to ask you that

Wow, this is cool. While Googling I found the original listing where my machine was sold to the previous owner. The guy before me parceled it out and sold the items individually for profit. Which I'm ok with, it's his side-gig, and he got to it before me. But what is cool is that I got a little bit of a story behind the Machine. Apparently, it was switched off 20 years ago, and stored in a warehouse. I'm curious what kind of business used it. I was hoping to find out something if the hard-drive still works.

alter Siemens Computer PC-MX2 / PC-2000 incl. 2 Terminals in Baden-Württemberg - Aalen | eBay Kleinanzeigen (ebay-kleinanzeigen.de)

Zitat von fritzeflink

If you have the manual please can you make a picture from the back so that we can see what is available?

I believe I have the photos you are looking for at the top post of this thread.

Thanks to fritzeflink helping me get a cable I'm now able to power on the system. I had my spirits up when all the fans spun up, even the hard-drive and floppy were making healthy sounds. The hard drive spins, but I get a repeating message on the screen "waiting for harddisk ready". You can see the boot sequence on the video below.

This is a bummer, but kind of expected. I would love to have the hard drive working so I can get the software off of it. But I'm not giving up hope. Maybe there is a problem on the control board that I can fix. Will see.

So, I'm going to be needing the MFM Emulator for sure. I have found three different kinds. I like the idea of the ones implemented in FPGA, but it won't help at all if everyone else in this space is using another, and I can't use their image files. Do you guys have any thoughts on the matter.

https://youtu.be/TngLWsyDbZ4

I've also been trying to learn how to use the monitor, and I'm unable to use the "d" command to display memory area.

So "d0 100" freezes the computer.

Memory test works when I run away from the beginning. "d2 ffff 100"

but "d2 0 100" freezes after two addresses come up on the screen.

Zitat von Peter z80.eu

Have you reseated all hdd relevant cables already ? Did you check the 5V and 12V power line of the drive (sometimes it's too low due to the age of the power supply, but high enough to let the drive spin) ?

I pulled it out when I first opened the computer up. All cables are reseated, I hear the click when it first starts spinning. I will probe voltage levels tonight.

Zitat von fritzeflink

Do you hear the HD spinning ?

Definitely spinning, and after a while it ramps down a little bit then up to normal. Everything sounds healthy. Could this be caused by a memory problem like what I posted about above?

Zitat von mlindroth

I've also been trying to learn how to use the monitor, and I'm unable to use the "d" command to display memory area.

So "d0 100" freezes the computer.

Memory test works when I run away from the beginning. "d2 ffff 100"

but "d2 0 100" freezes after two addresses come up on the screen.

Zitat von Peter z80.eu

Did you check the 5V and 12V power line of the drive (sometimes it's too low due to the age of the power supply, but high enough to let the drive spin) ?

I checked the power cables and both of the cables going to the hard drive are getting 5.118V & 12.76V.

Zitat von fritzeflink

insert the boot floppy to see the if that works

The disk should be named SINIX0.

I unfortunately didn't get any floppy disks, that's one reason I'm really interested in having a floppy emulator. So that I can load images from the internet.

Zitat von fritzeflink

but I see some floppydisks on the left in one of the top pictures. If you have none of them I can send you the disks.

They are blank except for a chess program, that may or may not be for my computer.

I have some awesome news. Over the past week I have been poking around in the system monitor to try to learn how to use it. I have been encountering some weird issues that cause the system to crash/hang while running commands. So I have figured I have some bad memory. Today while trying to do some commands to test some of the memory, I restarted the computer like I had done many times before, but I had the switches on the CPU card set to always go straight to the monitor. I heard some new clicks from the hard drive, this sound stopped me dead in my tracks because they sounded like the heads were finally moving. I set the switches back to normal, and restarted the systems. It gave me three error messages saying it was waiting for ready status from the drive, and I could hear it struggling. Then it finally booted into the system. I must have exercised it enough to get it working again.

I have two issues now; the default password doesn't work and I'm getting intermittent error messages on the bottom of the screen and the debug status LEDs are flashing. I'm hoping that once I get the floppies from Fritz, I will be able to delete a password file or something. As far as the error message, I'm hoping someone on here can help me understand it.

forum.classic-computing.de/index.php?attachment/155315/

Update: subsequent boots of the system don't have the heads moving reliably. I think it might be the sticky rubber bumpers. And the error messages were because the hard drive stopped working.

And I think that I might have read the password wrong before, I tried siemens: siemens. Oops.

Zitat von fritzeflink

Default ist :

root | siemens

admin | siemens

but the former owner might have changed the login.

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Yeah, I realized that after I had powered off the system. And the heads are sticking again. I'm going to have to open this drive. I'm planning on making a little clean room box with gloves attached to the front.