Submitted by Steve Fewell
Set A to the byte value at the location pointed to by &FD-&FE. &FD-&FD is the Operating System's
pointer to the last BRK (error message) instruction. The first byte of the error message is the Error Number (or ERR).
call routine &AE18 to set the IWA to the 1-byte value contained in A.
|AE3B||178 253||B2 FD||LDA (&FD)|
|AE3D||128 217||80 D9||BRA -39 --> &AE18 Set IWA to 8-bit value (in A)|