Java Byte Code, Ahead Of Time Compilers, And A TI-99

Java famously runs on billions of devices, including workstations, desktops, tablets, supercomputers, and jewelry. Yes, jewelry. Look it up. [Michael] realized Java doesn’t run on Commodore 64s, TI-99s, and a whole bunch of other platforms. Not anymore.

Last year, [Michael] wrote Java Grinder, a Java byte-code compiler that compiles classes into assembly language instead of being part of a JVM. This effectively turns Java from a Just In Time compiled language to a normally compiled language, like C. He wrote this for the 6502/6510, the MSP430, and a Z80. The CPU in the TI-99/4A is a weird beast, though, and finally [Michael] turned this Java Grinder on that CPU, the TMS9900.

While most of the development was accomplished with the MESS emulator, [Michael] did manage to run Java on real hardware. His friend gave him a TI-99/4A a few years ago with a few cartridges. Cracking those cartridges open revealed one PCB that would hold an EEPROM. Writing his Java byte-code-derived assembly to a 28c64 EEPROM, he had a cartridge that would run compiled Java.

Right now, the demo is pretty simple with low-resolution graphics beeps and bloops of music, and generally not what you would expect from a TI/99. This is mostly due to the fact that the API for the TI-99 is extremely simple. You can check out the results of that programming endeavor below.

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VCF East: Old Computers, New Games


While the vintage computer festival in Wall, NJ had just about every vintage app you could imagine – multiple varities of *NIXes, pre-Zork Dungeon, BASIC interpreters of all capabilities, and just about every game ever released for 8-bit Commodore systems – there was, perhaps unsurprisingly, a distinct lack of modern programs written for these retro systems. Yes, despite there being people still curled up to keyboards and writing games for vintage systems, modern software was a strange oddity last weekend.

There were two wonderful exceptions, however. The first was Fahrfall, a game for the TRS-80 Color Computer. We’ve seen Fahrfall before when [John Linville] wrote it for the 2012 RetroChallenge Winter Warmup. The game itself is a re-imagining of Downfall for the Atari Jaguar, with the graphics scaled down immensely. The basic idea of the game is to jump down, ledge to ledge, on a vertically scrolling screen. Hit the walls or the bottom, and you’re dead. It’s a great game that probably would have sold well had it been a contemporary release.

Next up is a rather impressive port of Flappy Bird for the TI-99. The video does not do this game justice, although part of that might just be the awesome Amiga monitor used for the display. This game was brought in by [Jeff Salzman] of Vintage Volts who isn’t the author of the game. Honestly, the video doesn’t do the graphics any justice. It really is a great looking port that’s just as addictive as the Android/iDevice original.

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