DECUS C combined with RT-11 v5.3

I have now managed to make an RX33 boot disk image from RT-11 v5.3 and Decus C.  However, I did have to remove some extra files from the original boot disk to make more space.  These are the extra files that I removed:

RT11BL.SYS, RT11PI.SYS, RT11AI.SYS, RT11FB.SYS, RT11SJ.SYS
STARTA.COM, STARTS.COM, STARTF.COM

I guessed that since I'm using the "XM" edition of RT-11, then I would not need those files.  Next, I copied over the DECUS C files, like this:

With CCDSK1.DSK in drive DK1:

CREATE sy:cdisk.dsk/allocate:1500
MOUNT ld0: sy:cdisk.dsk
ASSIGN ld0: c:
INITIALIZE c:
[LD0:/Initialize; Are you sure?] YES
COPY dk1:*.* c:

...now put disk CCXDSK.DSK in drive DK1:

If you've restarted the emulator to change disks, use the next two lines:
MOUNT ld0: sy:cdisk.dsk
ASSIGN ld0: c:

COPY dk1:*.* c:
@C:CCSET.EIS
@C:CCXASM.V53

Append these lines to your "STARTX.COM" command file (which runs when RT-11 starts):

MOUNT ld0: sy:cdisk.dsk
ASSIGN ld0: c:
@C:CCXASM.V53

Then restart... Finally, to compile a C program, do this:

CC
[CC>] hello.c/A
LINK sy:hello.obj,c:suport.obj,c:clib.obj

Don't forget that this is an old dialect of C, mainly as described by K&R.  So you'll have to stick to the original K&R syntax.  Right, next comes the fun stuff.