In my previous post the machine was disassembled and the battery removed. Since then I’ve been coming back to this machine on and off over the last week. In this post we dig a bit further to see if we can get the machine running.

Boot Disk

Before I take a look further at the motherboard I wanted to take a look at the boot disk. I have a Greaseweazle which allows floppy drives to be connected to a USB port along with tools to read disks at a very low level. This is much better than using a stock USB floppy drive, which is usually too abstracted away to be able to read things such as Amiga floppy disks.

I found a drive which has been quite reliable to do this and read the disk.

There were a few sectors which were not readable, but I managed to get an image of the disk which is below (in case anyone needs it). Looking at the contents it appears to be somewhat Euro PC specific. You can download it from my Downloads page.

To make sure this would boot, I use Bochs to boot an emulated PC from the disk. At this stage I still haven’t figured out if any files on the disk are corrupted due to the sectors that couldn’t be read, but it booted without issue. It was a little weird to use because the keyboard mapping was German based, which I guess is to be expected. I’m guessing the Euro PC hardware remaps the QWERTY keyboard to the German layout.

One of the most important things on the disk was a file called “SETUP.EXE”. This is a tool to configure the BIOS of the Euro PC from DOS. It was worth backing up the disk for this alone. Saving the settings causes Bochs to become no longer bootable, which is probably to be expected, it is a very different BIOS. Interestingly the clock was running incredibly fast (this schreenshot below was taken a couple of hours before the time shown). I haven’t used Bochs much so I’m guessing it is something to do with the emulation.

Battery Cleanup

I had previously snipped the battery from the motherboard, but I still needed to remove the bits of metal left behind. For this, I broke out the Hakko FR-410 desoldering gun. It made light work of what remained.

I built a version of my low-loss battery mod on long wires so that when I solder it to the PCB the battery can be in the ISA card bay area for ease of changing at a later date. I don’t want to fit this just yet, I want to see if the machine is bootable first.

Video

As this is a TTL CGA/MDA output from the machine, I couldn’t just hook up a VGA cable and cross my fingers. This machine requires a little conversion to generate the right picture. I could have knocked up something hacky myself but I decided to get something I’d use more long-term. I ended up ordering an RGBtoHDMI board with a TTL adaptor and a CGA2SCART Pro, which both happened to arrive on the same day.

I decided to use the RGBtoHDMI, partly due to the fact I have everything setup for testing Amiga RGBtoHDMI models, and partly down to not being able to find a SCART<->SCART cable in my workshop at the time.

Power!

With that hooked up, it is time to power-on and see what happens…

That is a surprisingly good outcome, I was expecting a lot of errors due to the battery missing and the beeping I was hearing. I’m a little concerned about the RAM counter, but maybe that is a default size when the BIOS settings are at their default?

Either way I’m happy to get this far. To wrap things up this time I quickly checked the thermals to see if anything was obviously bad.

The CPU is running a little hot, but I’m going to be changing that for an NEC V20 at a later date which should run a little cooler. The logic chips above the RAM are a little warm too, I don’t think they are bad though. I was looking for hot RAM chips anyway and I don’t see any of those.

Next time I’ll hook up the keyboard and battery as well and see if we can get any further.