Shells for Toys

Do you own one of the Retro Games mini consoles, such as a THEA500 Mini (Commodore Amiga) or THEC64 Mini (Commodore C64), The Spectrum (Sinclair ZX Spectrum), or THE400 (Atari 400)? They are great gadgets for playing retro games, but they also run a Linux kernel, so you can connect a USB keyboard and turn the toy into a text-mode terminal. Some of these machines will even let you connect an Ethernet adapter or a WiFi dongle so that you can log in to other machines.

Running a Shell

Because none of the Retro Games machines were intended to be used as anything other than emulators for the classic home computers that they mimic, getting shell access requires a hack. There are three ways this can be accomplished (two are easy and one is a bit more complicated):

• Fake Update: The retro computers provide a mechanism for installing firmware updates. That mechanism can be exploited so that the machine will run arbitrary code.
• The WHDLOAD package (for THEA500): The Amiga emulator Amiberry that's used in THEA500 uses WHDLOAD to run Amiga games, and the specific combination of Amiberry and WHDLOAD on THEA500 can (again) be exploited to run any code.
• FEL mode: For some of the Retro Games mini consoles, there is no such hack. Instead, you'll have to enter Firmware Exchange Launch (FEL) mode by connecting the console to a PC via a special USB-A-to-USB-A cable and pressing a button on the board during startup (Figure 1). Then, you can inspect the contents of the machine's NAND flash chip and modify or add your own files.

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