I have compiled these versions:
PUSH32:  http://oldcomp.cz/download/file.php?id=12322
PUSH64: http://oldcomp.cz/download/file.php?id=12321

ub880d helped and enabled somehow at least the LS command:

POKE 45716,218
POKE 49372,1
POKE 49376,45
POKE 49705,38
POKE 49706,0
POKE 49707,0
POKE 49708,208

**push** is a very small, yet feature rich shell for embedded systems.

While it builds successfully for all target platforms, it is only really working well on Linux and C64 (and most recently on ZX-Spectrum). The main reason is lacking/broken support for some features from the C runtime libraries on some platforms, most important CONIO and heap management. Hopefully over time the toolchains will provide those APIs.

The Makefile in `./push/src` contains various targets for compiling and testing:

**make zx** (build zx spectrum tap)
**make zx64** (build zx spectrum tap with 64 columns)
**make zxn** (build spectrum next tap)
**make zxemu** (start tap in zesarux)
**make zx64emu** (start 64 columns tap in zesarux)