21 questions
1
vote
0
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49
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Why does +JSUB in SIC/XE behave differently from LDA regarding dereferencing?
I’m learning SIC/XE assembly and I ran into a confusing behavior with addressing modes. Consider these two examples:
MOJPRG START 0
+JSUB #WRREC
HALT J HALT
WRREC RSUB
MOJPRG START 0
+JSUB ...
- 48
0
votes
0
answers
49
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my SIC assembly program is printing 00 00 00 as an output
here is the SIC code, it is printing 00 00 00 to device 64 when I run it inside the SIC simulator provided to me:
CLOCK START 3072
T WORD 48500
D WORD 64
H RESW 1
M ...
- 1
0
votes
1
answer
92
views
What does a linkage register actually do in sic
This is a sic assembler program where a reading and writing is done:
Here the value in linkage register is stored in RETADR.but I don't see it using in RSUB call ...so if not for subroutine call why ...
- 1
0
votes
1
answer
113
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Confused in understanding JLT *-19 in SIC/XE means
This is a program from LELAND L beck's book on System Software (An introduction to system programming)
I am trying to understanding how MACROS work
this demonstrates the use of macro
My doubt is what ...
- 988
0
votes
1
answer
302
views
How does RESW in SIC machine works
This is instructions set give in the standard text of System program
( Leland L Beck )for transferring data 5 from accumulator to memory
As you all know SIC is a hypothetical machine
LDA FIVE Load ...
- 988
0
votes
1
answer
627
views
How can I obtain the length of text from object code in SIC Assembler?
COPY START 3000
** LDA THREE
** STA ALPHA
** LDCH CHARC
** STCH C1
** LDCH CHARZ
** STCH C3
ALPHA RESW 3
THREE WORD 3
CHARC BYTE C'FO'
C1 RESB 3
CHARZ BYTE C'EOF'
C3 RESB 3
** END **
This is the ...
- 23
0
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0
answers
27
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How does (SIC) assembler print hash tables? [duplicate]
I am trying to make an assembler in C for the SIC architecture.
And I saw that symbol table and object code table are usually made with hash tables.
What I wonder is, how assemblers print these tables....
- 23
0
votes
0
answers
1k
views
How can I translate sic/xe to object code?
Above sic/xe code,
I don't understand translate process.
105F LDT LENGTH => 774000
1056 EXIT STX LENGTH => 134000
I already know translate opcode and 000.
But I don't know how ...
- 57
1
vote
0
answers
676
views
SIC about BYTE X and C
BYTE X'05'
BYTE C'05'
what is difference between X and C?
if I want to write object program,how can I make LOC?
- 11
1
vote
1
answer
3k
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Adding and storing value in SIC/XE machine
; Assembly Program
;¯¯¯|¯¯¯|¯¯¯|¯¯¯|¯¯¯|¯¯¯|¯¯¯|¯¯¯|¯¯¯|
; |
; Programmer: joe247 |
; |
;___|___|___|___|___|___|___|...
- 398
0
votes
1
answer
216
views
SIC/XE Can I put new value to a value that already has its own value?
Hi I'm taking a system software class on my uni and I'm making an assembly code with SIC. I've already written a code with C. So I'm translating it to SIC and I got a question about variable policy of ...
- 287
0
votes
0
answers
688
views
BYTE operation confusion in SIC assembly object code
While trying to make an assembler for SIC, I thought of these questions.
LABEL BYTE X'AB'
Here the generated object code would be AB. So the object code might look something like this as an ...
1
vote
0
answers
958
views
Fibonacci for SIC/XE assembly
Can someone help explain the following code. I'm trying to add comments to the following SIC/XE program that explains how this program is calculating a fibonacci sequence for the first 20 numbers, ...
- 11
0
votes
1
answer
797
views
assembly language syntax issue for arithmetic
I have a fairly simple question regarding assembly language. We are using SIC/XE architecture which is basically make believe and for educational purposes only, but does follow the common conventions ...
- 27
0
votes
1
answer
4k
views
confusion on generating object code in SIC assemblers output
So right now I'm trying to understand how object code is generated but thse two lines really confuse me, anyone want explain it to me?
RSUB is 4C0000, I understand RSUB is 4C Mnemonic, but where did ...
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