How do I get toy chips for hobby projects?

Some people who read my article became all excited about the possibility of being able to buy a microcontroller for under a dime. They were thinking of using these parts in their own hobby projects. Unfortunately, almost all electronic toys are based around parts intended specifically for the toy industry. These chips are not end-user-programmable and are not sold encapsulated; they are sold as bare, mask-programmed dice (and only in large quantity at that; masking minimum quantities are usually at least 1000, usually more like 5,000). It's the toy manufacturer's responsibility to put those dice on a board, bond them out to the PCB tracks and encapsulate them in epoxy. Even if you could buy these chips in small quantity (which you can't), and even if you could upload code to them (which you usually can't), physically mounting and connecting to them isn't really something you can do at home.

To develop with these parts, you use two resources. First, there will be an in-circuit-emulator (ICE) for the part in question. This is a large board that connects to your PC, usually via parallel port. It usually has a large RAM buffer on it, as well as what the chip companies call the "chip body", which is a ROMless version of the part you're interested in, packaged in regular DIP packaging with extra pads bonded out for external memory. You can develop your code fairly rapidly on this board.

For looks-like, works-like prototypes, you will use a demo board. This is a small PCB with a ROMless chip body (COB package) mounted on it, and space for you to add an EPROM or EEPROM containing your code.

The ICE board and demo boards, not to mention the required proprietary assembler/linker/uploader software, are only available from the chip manufacturer. You can't buy these parts off the shelf at retailers like Digi-Key et al. If you want to try establishing a relationship with a chip vendor, some names to try are: EMC, Sunplus, Winbond and Sonix. However I don't recommend using these parts for hobbyist projects. The demo boards, once you populate them with memory, are significantly more expensive than normal embedded control parts like PICs, 8051s and AVRs, and the tools are idiosyncratic. You can't expect to receive any peer support for them, either.

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