A simple SIC/XE tow-pass assembler, implemented in python supports relative addressing and seperating program block
- Instruction Formats & Addressing Mode
- Direct Addressing Mode
- Indirect Addressing Mode
- Simple Addressing Mode
- Immediate Addressing Mode
- Program Counter (PC Register)
- Base (Base Register)
- Extended Instruction (4bit Instruction)
- Program Relocation
- Program Blocks
- Control Sections
- Program Linking
- Enternal
- Reference
- Modification Record
- Others
- Literal
- Pass One
- Record every program block information
- Symbols
- Literals
- External Define
- External Reference
- Modification Record
- Counting program address
- Record every program block information
- Pass Two
- Instruction Format
- Generating Machine Code
| Mnemonic | Format | Opcode | Effect | Notes |
|---|---|---|---|---|
| ADD m | 3/4 | 18 | A ← (A) + (m..m+2) | |
| ADDF m | 3/4 | 58 | F ← (F) + (m..m+5) | F |
| ADDR r1,r2 | 2 | 90 | r2 ← (r2) + (r1) | |
| AND m | 3/4 | 40 | A ← (A) & (m..m+2) | |
| CLEAR r1 | 2 | B4 | r1 ← 0 | |
| COMP m | 3/4 | 28 | A : (m..m+2) | C |
| COMPF m | 3/4 | 88 | F : (m..m+5) | CF |
| COMPR r1,r2 | 2 | A0 | (r1) : (r2) | C |
| DIV m | 3/4 | 24 | A : (A) / (m..m+2) | |
| DIVF m | 3/4 | 64 | F : (F) / (m..m+5) | F |
| DIVR r1,r2 | 2 | 9C | (r2) ← (r2) / (r1) | |
| FIX | 1 | C4 | A ← (F) [convert to integer] | |
| FLOAT | 1 | C0 | F ← (A) [convert to floating] | F |
| HIO | 1 | F4 | Halt I/O channel number (A) | P |
| J m | 3/4 | 3C | PC ← m | |
| JEQ m | 3/4 | 30 | PC ← m if CC set to = | |
| JGT m | 3/4 | 34 | PC ← m if CC set to > | |
| JLT m | 3/4 | 38 | PC ← m if CC set to < | |
| JSUB m | 3/4 | 48 | L ← (PC); PC ← m< | |
| LDA m | 3/4 | 00 | A ← (m..m+2) | |
| LDB m | 3/4 | 68 | B ← (m..m+2) | |
| LDCH m | 3/4 | 50 | A [rightmost byte] ← (m) | |
| LDF m | 3/4 | 70 | F ← (m..m+5) | F |
| LDL m | 3/4 | 08 | L ← (m..m+2) | |
| LDS m | 3/4 | 6C | S ← (m..m+2) | |
| LDT m | 3/4 | 74 | T ← (m..m+2) | |
| LDX m | 3/4 | 04 | X ← (m..m+2) | |
| LPS m | 3/4 | D0 | Load processor status | P |
| MUL m | 3/4 | 20 | A ← (A) * (m..m+2) | |
| MULF m | 3/4 | 60 | F ← (F) * (m..m+5) | |
| MULR r1,r2 | 2 | 98 | r2 ← (r2) * (r1) | |
| NORM | 1 | C8 | F ← (F) [normalized] | F |
| OR m | 3/4 | 44 | A ← (A) (m..m+2) | |
| RD m | 3/4 | D8 | A [rightmost byte] ← data | P |
| RMO r1,r2 | 2 | AC | r2 ← (r1) | |
| RSUB | 3/4 | 4C | PC ← (L) | |
| SHIFTL r1,n | 2 | A4 | r1 ← (r1); left circular shift | |
| SHIFTR r1,n | 2 | A8 | r1 ← (r1); right shift n bits | |
| SIO | 1 | F0 | Start I/O channel number (A) | P |
| SSK m | 3/4 | EC | Protection key for address m | P |
| STA m | 3/4 | 0C | m..m+2 ← (A) | |
| STB m | 3/4 | 78 | m..m+2 ← (B) | |
| STCH m | 3/4 | 54 | m ← (A) [rightmost byte] | |
| STF m | 3/4 | 80 | m..m+5 ← (F) | F |
| STI m | 3/4 | D4 | Interval timer value ← (m..m+2) | P |
| STL m | 3/4 | 14 | m..m+2 ← (L) | |
| STS m | 3/4 | 7C | m..m+2 ← (S) | |
| STSW m | 3/4 | E8 | m..m+2 ← (SW) | P |
| STT m | 3/4 | 84 | m..m+2 ← (T) | |
| STX m | 3/4 | 10 | m..m+2 ← (X) | |
| SUB m | 3/4 | 1C | A ← (A) - (m..m+2) | |
| SUBF m | 3/4 | 5C | F ← (F) - (m..m+5) | F |
| SUBR r1,r2 | 2 | 94 | r2 ← (r2) - (r1) | |
| SVC n | 2 | B0 | Generate SVC interrupt | |
| TD m | 3/4 | E0 | Test device specified by (m) | PC |
| TIO | 1 | F8 | Test I/O channel number (A) | PC |
| TIX m | 3/4 | 2C | X ← (X) + 1; (X) : (m..m+2) | C |
| TIXR r1 | 2 | B8 | X ← (X) + 1; (X) : (r1) | C |
| WD m | 3/4 | DC | Device specified by (m) ← (A) | P |
COPY START 0
EXTDEF BUFFER,BUFEND,LENGTH
EXTREF RDREC,WRREC
FIRST STL RETADR
CLOOP +JSUB RDREC
LDA LENGTH
COMP #0
JEQ ENDFIL
+JSUB WRREC
J CLOOP
ENDFIL LDA =C'EOF'
STA BUFFER
LDA #3
STA LENGTH
+JSUB WRREC
J @RETADR
RETADR RESW 1
LENGTH RESW 1
LTORG
BUFFER RESB 4096
BUFEND EQU *
MAXLEN EQU BUFEND-BUFFER
RDREC CSECT
.
. SUBROUTTINE TO READ RECORD INTO BUFFER
.
EXTREF BUFFER,LENGTH,BUFEND
CLEAR X
CLEAR A
CLEAR S
LDT MAXLEN
RLOOP TD INPUT
JEQ RLOOP
RD INPUT
COMPR A,S
JEQ EXIT
+STCH BUFFER,X
TIXR T
JLT RLOOP
EXIT +STX LENGTH
RSUB
INPUT BYTE X'F1'
MAXLEN WORD BUFEND-BUFFER
WRREC CSECT
.
. SUBROUTINE TO WRITE RECORD FROM BUFFER
.
EXTREF LENGTH,BUFFER
CLEAR X
+LDT LENGTH
WLOOP TD =X'05'
JEQ WLOOP
+LDCH BUFFER,X
WD =X'05'
TIXR T
JLT WLOOP
RSUB
END FIRST
HCOPY 000000001033
DBUFFER000033BUFEND001033LENGTH00002D
RRDREC WRREC
T0000001D1720274B1000000320232900003320074B1000003F2FEC0320160F2016
T00001D100100030F200A4B1000003E2000454F46
M00000405+RDREC
M00001105+WRREC
M00002405+WRREC
E000000
HRDREC 00000000002B
RBUFFERLENGTHBUFEND
T0000001DB410B400B44077201FE3201B332FFADB2015A00433200957900000B850
T00001D0E3B2FE9131000004F0000F1000000
M00001805+BUFFER
M00002105+LENGTH
M00002806+BUFEND
M00002806-BUFFER
E
HWRREC 00000000001C
RLENGTHBUFFER
T0000001BB41077100000E32012332FFA53900000DF2008B8503B2FEE4F0000
M00000305+LENGTH
M00000D05+BUFFER
E