While difficult to find in official archives today, a fully functioning copy of HI-TECH C for 8051 XA recently surfaced on Matt Millman's Tech Blog . You can also find legacy downloads of the HI-TECH C51-lite edition on platforms like Software Informer . If you'd like, I can:

HI-TECH C51-lite. ... HI-TECH C51-lite is the evaluation edition of HI-TECH Software's C compiler for the Intel MCS-51 (8051/8052) Informer Technologies, Inc. HI-TECH C COMPILER FOR PIC10/12/16 MCUS (PRO)

In the world of technology, "Hi-Tech C51" typically refers to two very different things: a specialized software compiler for microcontrollers or a high-performance industrial V-belt Here are two short stories based on these interpretations: The Ghost in the Silicon (Software Perspective)

This granularity allowed programmers to squeeze every last byte of performance from the chip.

The Hi-Tech C51 uses a linker script ( .lkr file) that defines the memory layout of your specific 8051 derivative. You must ensure the linker knows where your CODE, DATA, and XDATA segments live.