I use IFOX00. Okay, you can laugh now.
Since IFOX00 doesn't support any RXE or RXY instructions,
someone wrote a MACRO to use an RX instruction to generate RXE and RXY
instructions.
It just codes an RX instruction like LA, STC, or IC and then overlays the
opcode and adds two bytes to the end.
Displacement-high is not supported so is always zero.
The question is on the ORG use.
The code does:
ORG *-4
DC XL1'E3' Overlay the opcode
ORG *+3
My question is the second ORG.
Should it instead be ORG , ?
Which is safer?
Could a later errant "ORG ,' mess thing up royally?
Am I needlessly worrying?
Note: IFOX00 was before LOCTR instruction existed.
An entire MACRO after I restructured and modified:
MACRO
&LBL STY &R1,&BXD
.*
.* Generate STY Opcode in IFOX00
.*
DS 0H Instructions on a half-word boundary
AIF ('&LBL' EQ '').NL Skip unlabelled length set
&LBL EQU *,6 Set Instruction Length of 6
.NL ANOP ,
.*
.* Use LA opcode to generate Base and Index Registers and
.* DL Displacement for E3 Store instructions
.*
STC &R1,&BXD Dummy instruction to build STY on
ORG *-4 Go back to overlay op-code
DC XL1'E3' Set op-code to E3
.*
.* Zero DH and set Sub Opcode
.*
ORG *+3 Go forward to end STY instruction
DC X'0050' Last two bytes of STY
MEND
