My first was Intel 8086 4.77MHz with a 8087 co-processor. It was a really great machine for basic programming and some first DOS games like Space Invaders, Alley Cat, Paratroopers and more.
A 486DX2 66MHz was my second but it's worth mentioning because it was a really significant step and my first touch to x86 assembly programming, 3D ray tracing, animation apps, video capturing and so on... also the games Doom, Descent and many others.
I don't have any photos but found an exact match of the bios boot screen on the same kind of monitor (amber monochrome up to 720x348 pixels). Never got that particular error though.