Zork And The Z-Machine: Bringing The Mainframe To 8-bit Home Computers

Computer games have been around about as long as computers have. And though it may be hard to believe, Zork, a text-based adventure game, was the Fortnite of its time. But Zork is more than that. For portability and size reasons, Zork itself is written in Zork Implementation Language (ZIL), makes heavy use of the brand-new concept of object-oriented programming, and runs on a virtual machine. All this back in 1979. They used every trick in the book to pack as much of the Underground Empire into computers that had only 32 kB of RAM. But more even more than a technological tour de force, Zork is an unmissable milestone in the history of computer gaming. But it didn’t spring up out of nowhere.

DEC PDP-10 Flip Chip module
DEC PDP-10 Flip Chip module

The computer revolution had just taken a fierce hold during the second World War, and showed no sign of subsiding during the 1950s and 1960s. More affordable computer systems were becoming available for purchase by businesses as well as universities. MIT’s Laboratory for Computer Science (LCS) was fortunate to have ties to ARPA, which gave MIT’s LCS and AI labs (formerly part of Project MAC) access to considerable computing resources, mostly in the form of DEC PDP systems.

The result: students at the MIT Dynamic Modeling Group (part of LCS) having access to a PDP-10 KA10 mainframe — heavy iron at the time. Though this PDP-10 was the original 1968 model with discrete transistor Flip Chip modules and wire-wrapping, it had been heavily modified, adding virtual memory and paging support to expand the original 1,152 kB of core memory. Running the MIT-developed Incompatible Timesharing System (ITS) OS, it was a highly capable multi-user system.

Naturally, it got mostly used for playing games.
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Novice Coders Can Create Classic Game Boy Games

It takes a lot of work to build a modern video game. Typically an entire company will spend months (at least) developing the gameplay, selecting or programming an engine, and working out the bugs. This amount of effort isn’t strictly necessary for older video game systems though, and homebrew developers are quite often able to develop entire games singlehandedly for classic systems. In the past it would have taken some special software, programming knowledge, and possibly hardware, but now anyone can build games for the original Game Boy with minimal barriers of entry.

The project is known as GB Studio and allows people to develop homebrew games for the 8-bit handheld system without programming knowledge. Once built, the games can be played on any emulator or even loaded onto a cartridge and played on original hardware if a flash cart is available. Graphics can be created with anything that can create a .png image, and there are also some features that allow the game to be played over a web browser or on a mobile device.

While it seems like the gameplay is limited to RPG-style games, this is still an impressive feat, and highly useful for anyone curious about game development. It could also be an entry into more involved game programming if it makes the code of the games available to the user. It could even lead to things like emulating entire cartridges on the original hardware.

Thanks to [Thomas] for the tip!

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Set Your Nuts (and Bolts) Free With This Induction Heater

[Amon] built an induction heater to break stuck bolts loose. If you work on cars, machines, or anything big and metal, sooner or later you’re going to run into stuck nuts and bolts. Getting them unstuck usually involves penetrating oil, heat from a torch, and cheater bars. Heat usually works well, as heating the bolt makes the metal expand, helping it to break free. Torches aren’t exactly precision instruments though, and things can get interesting using one in tight spaces.

Fire isn’t the only way to heat a bolt through. Electricity can do the job as well. But why use a heating coil when you can grab an induction heater. Mechanics have had induction heaters in their toolboxes now for a few years, under names such as Bolt Buster or Mini Ductor. These devices cost several hundred dollars. However, you can purchase a 1000 watt induction heater from the usual sources for around $30. These are open frame Zero Voltage Switching (ZVS) power supplies, with uninsulated copper coils.

[Amon] bought one of these induction heaters, along with a beefy 24V, 40 amp switch mode supply to power it. He built the two into a plastic enclosure. A relay energizes the induction heater, so it isn’t always running. The key to this build is the handle. Rather than mount the induction coil directly on the supply, [Amon] ran two extension wires to a 3d printed gun style handle. This keeps the bulky part of the heater away from the work. The copper tube coil was re-shaped to better work with the gun. Some fiberglass sleeve keeps everything insulated, even at extreme temperatures.

The result is a very useful heater, ready to bust loose some bolts. We’ve seen homebuilt ZVS supplies powering induction coils before. It will be interesting to see how well these commercial units hold up.

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