[jonaslasky]

Firmware is programmable logic. They have the best of both worlds. The speed of hard wired devices but with the flexibility of a programmable device... so it's almost like software. The chipsets on your motherboard is firmware, so it can be upgraded via software. But the software in that case doesn't run the chipset at runtime. Rather the software actually rewires the chipset via a built in programmer hardware. After the upgrade is done the firmware gains new functions.... as if it's a totally new machine. A lot of hardware is now built with programmable logic because upgradability is a big selling point. In the early days, programmable logic chips were so bulky and expensive that they were only used for the most expensive machines or peripherals. Now everyone is using them. It's like having custom made chips for every product you're working on.... a luxury that was unthinkable not too long ago.

EPROMS or EEPROM are OK but they are very slow and limited... so they're not very well suited for really high performance application. But they are used for programming programmable logic in some cases. Programmable logic (CPLD and FPGA) on the other hand are very fast and work at voltages compatible with modern processors. They have switching times in the nano second range.

A few people have actually proposed building computers on programmble logic instead of processors. The idea is, you would have a dedicated hardware for every type of processing you want to do. When you're done with a particular type of computing, you reconfigure the logic to be something else entirely. It would be frighteningly fast if anybody ever actually built a machine like that. But these projects are just starting. I do recall reading a claim that someone has come up with a system that could be reconfigured very quickly.... quickly enough so you didn't notice it too much.... of course there would be no multi-threading on those machines. But if you were trying to render a feature length animated film... you'd be willing to live with some limitations in exchnge for lighting quick 3-D rendering.

Jonas