Today, I finally had time to take care of the #MysteryMachine again. I removed the HDD and dumped it several times using David Gesswein's MFM emulator. The hard drive seems to be in perfect working order. Now I'm excited to see what data treasures await me there.
Wow! A new video drops! It's a miracle!
This week on "The ChickenHead Chonicles" am am talking about a very... interesting Commodore SFD-1001 Disk drive I found. Come check it out!
youtu.be/KBOuNaLGeSI
Great to see you back, Doug! Hope you're doing well.
A "normal" 512K RAM expansion
Doing it old school! My latest acquisition for the #Amiga 500 with Kickstart 1.3: A GVP Impact A500-HD8+ with 2 MB. I replaced the broken HDD with a ZuluSCSI and am now copying Workbench 1.3 from floppy disks. Next, of course, I need to install Monkey Island (happy disk changing) 😅
Today, I took care of the power supply of the #MysteryMachine. I unplugged all the cards, drives and the CRT and measured the 5V and 12V rails without load.Then I created some load with an old hard drive and let it run for 20 minutes – the PSU remained completely stable, absolutely rock solid. 👍
I've made some progress exploring the #MysteryMachine. Using my Greaseweazel, I was able to create an image of the floppy disk I found in the machine's TEAC FD-55B. We were able to make the contents readable. It appears to be some kind of CP/M machine with Heckler & Koch's own MT4 file format.
The first findings in the hex dump are interesting: apparently a system monitor called MOSMON, which seems to be quite capable, and a set of disk commands and messages such as ‘DISK NOT READY WAIT PLEASE...!’
I have dumped the 2764 EPROM labelled ‘MOS 2.0 0.4/10’ with my TL866-II+. To be on the safe side, I did this three times and compared the results with HxD.
And the firmware: 104521E for Xebec S1410
Hard drives supported: Two ST-506/412(MFM) drives
I did some research, and the three controller chips together with the Z80 processor point to an MFM controller, similar to the IBM Fixed Disk Adapter - theretroweb.com/expansioncar...
3198-0025 (Data Separator) - theretroweb.com/chips/10211
3198-0009 (SERDES ECC) - theretroweb.com/chips/10212
Here are the photos of the Seagate ST-412 hard disk. It is interesting to note that it appears to have a type of daughterboard mounted on the drive electronics, with its own Z80 processor. I suspect that the daughterboard is the HDD controller.
Wow, very well spotted. I had completely overlooked that. I will try to read out the EPROM with my TL866. I will also try to image the hard drive before digging deeper.
Oh, that could be. There is actually a Heckler & Koch logo on the PSU card. I didn't know they used to build PCs. In fact, the company headquarters is only 75 km away from me. How did you figure that out?
Here are a few more pictures of the other plug-in cards.
Over the last few days, I've had a little time to explore the #MysteryMachine further. It seems to be completely bus-based; even the PSU is a plug-in card. Obviously Z80-based. After some initial research, it could be a CP/M computer with an ECB bus. Does anyone recognise it?
I'm in Germany. We have 240 volts mains.
I'm not turning it on yet. I want to check the power supply first – I don't want it sending 240 volts into the system. So I need to open it up and examine it first.
It seems to be painted over.
I'm starting to think it was either a word processor or a developer's machine.
A colleague brought me this computer that she found while clearing out her father's old company. He used to develop ERP software for IBM. She actually wanted to throw the computer in the bin 🫣 Thank goodness she told me about it first.
Today, I took care of the exterior appearance of the #mysterymachine and cleaned it thoroughly. Here are a few more pictures of the keyboard, the back and the bottom. I can see plug-in cards through the slots. Now I have to find the right screwdriver, because that's obviously not standard either.
I'll post some pictures later.
No, definitely not a Compaq. And it's not luggable, the keyboard cannot be attached
Today I rescued this gem from the rubbish bin. However, I'm not sure what kind of device it is. There is no model sticker or other clues. It obviously has a hard drive and a floppy disk drive, so I think it must be a PC rather than a terminal. Over the next few days, I'll take a closer look at it.
Can't wait! CU there.😎
Happy 40th to the legend that is the Amiga computer.
#amiga #retro #nostalgia #tech
