'Tar' & feathered (ESIX)

[Weil timothy]

Thanks so far so suggestions re: GCC under ESIX...
Have acquired 'LS-LR.Z' & 'GCC1371.Tar.Z' for
installation & education...
 
Problem with ESIX 'tar' command....Tried 
          'tar xvf ls-lr.Z'    and...
got messages like
    1). Bad checksum on directory
    2). Invalid blocksize (Blocks=20)
do I need a different version of tar under
ESIX for GNU (like tar.Z).
 
Problem with GCC1371.Tar.Z is that host system
(Vax Ultrix) denies access to 'Tar' & this
1.5M file wont fit to floppy medium & requires
about 4 hours to download at 2400 baud!!!
 
Nothings easy, eh????