The article said that it was only possible to compile the code with SDCC
so I did some small tests with the source and Keil.
I created a empty project in UV2 and setup the sources.
After modifing the at 0x???? to the Keil syntax and rewriting the delay_ms
function in C because Keil does not support ASM like SDCC , the code
compiles fine (2 Warnings about unused LCD Functions)

Code size was about 8k in Keil (OT=default=8) and 11k in SDCC.
With OT=9 code size was less than 6k...

I have not done any runtime tests with the code because this would
require some real HW.

I used the small memory model but there is not much difference in
the large memory model, because most of the vars are declared
with xdata.

Thomas