Turtles All The Way Down

So I was going to write about IBM LOGO for the PC-XT, but then I fell down a rabbit hole. Dual. Screens. In. Dos. I had heard of such things as a youngling but I had never witnessed them. Now as a nostalgic greybeard I was intrigued when I stumbled upon the .SETSCREEN command in the IBM LOGO for DOS manual that I was reading for my post about IBM LOGO. TWO SCREENS! IN DOS! IN LOGO! IN DOS! WHAT MAGIC IS THIS? Multiple monitors in DOS was never very common. Of course it required two video cards, and one of them had to be an MDA card (or hercules, maybe?). MDA stands for "Monochrome Display Adapter" but more specifically it was a text-mode only adapter; no graphics modes. That's basically the magic that makes it work. The MDA card is so old and weird that it can exist alongside newer CGA or EGA (or even VGA?) cards without hardware or driver conflicts. Okay so first I needed to get a PC with an MDA card and a CGA card or something. Those aren't easy to find. So I tried ...

TL;DR Use “legacy hardware”, “pcnet” ethernet, and add this to QEMU options to enable a shared drive: -device  ide-hd,bus=ide.1,unit=0,drive=sharedDrive -drive  if=none,media=disk,driver=vvfat,id=sharedDrive,file=fat:rw:/path/to/shared Fix /path/to/shared, obviously. Getting Started First download and install UTM SE from the app store. Create VM Open UTM SE and tap New VM Set the live cd ISO image as the boot image 8gb is a pretty reasonable size. It’s a sparse file so it will really only be about 1gb for a full install. Legacy HW sets SYSTEM to this, leave it. Set ram to whatever but 32mb is basically infinity for DOS. 1MB would be enough for our needs. We’ll set up sharing later It should look like this: Fix Networking PCNET is the first one i found that worked Install FreeDOS I suggest doing a full install. That requires two CDs, the live and the bonus. Use “fdimples” to install the bonus and any other packages after doing the “full” or base install. When you boot FreeDos a...

Welcome to my logo programming blog. In this blog, I'll be exploring the past present and future of the logo programming language. I'm gonna assume you already know what logo is. Otherwise how do you even find this? If not, go here for an introduction. Why am I interested in logo? Logo was the first computer programming language that I ever used, back in 1986, when I was seven years old, and I was immediately hooked on programming. After logo, I taught myself basic. In hindsight, I ought to have just stuck with logo. Line numbers are for the birds. But like many new programmers, I associated logo heavily with turtle graphics, not realizing the full scope and power of logo of the programming language. It also didn't help that I was developing logo mostly on Apple ]['s with their arcane DOS, which didn't exactly encourage interoperability with the wider world. 40 years later and I'm still pounding the keys. I've forgotten more about programming computers t...