I guess I should chime in here.

Keil officially makes 2K-limited evaluation tools (compiler, assembler, linker, debugger) for the 8051. This is what's available on our web site.

There are several reasons Keil doesn't make a 4K-limited toolset. Basically, it boils down to providing technical support to the non-paying 4K tool customers versus the paying unrestricted tool customers.

Nonetheless, many chip vendors have requested 4K-limited tools for their specific devices or boards. All of the Keil 4K-limited tool sets are custom tailored for the chip vendor to showcase that vendor's devices/features.

Hopefully, that clears up some of this Keil-specific 4K development tool stuff.

Jon