[Coco] Call code Syscall

[Taylor, Phillip L CIV]

Hello

I was looking at some old code that was written to run under the Old Tandy Os9 Level 2 and I am trying to figure out where the call code is in the /dd/defs file.

Regs.A = 0
Regs.Y = 1
Regs.B = $84
Regs.X = $6401
Run Syscall ($8e,regs)

Executing $8e and the call code is $84. This location may have several different call codes and I am trying to see all the call codes for this address and what each one does?