IBM Assembler

It will give an error at the time of assembly, if there are

some labels defined in the program(provided they are being

referenced in your program). This is because the assembler

resolves the displacement of that variable from the location

where your base register is pointing to.

it all depends upon the length of your program , if it is

more than 4095 then we need 2 register else only one can do

needful.

basically we can even use savearea register as a base

register, so as to accomodate the length of the program

R1 contains a fullword that contains a address pointing to

tyhe parm data. In pgm before accessing the parm data use L

Rn,0(,R1) where n=3,..11 , Rn contains the address that

points to parm data. Create DSECT that contains a halfword

and the length of the data.

Use Accept in procedure division.

Example :

WORKING-STORAGE SECTION.

01 empno. Pic x(05).

01 empname pic x(15).

01 empsal pic 9(10).

PROCEDURE DIVISION.

................

PERFORM ACCEPT-PARA.

..............

ACCEPT-PARA.

ACCEPT EMPNO.

ACCEPT EMPNAME.

ACCEPT EMPSAL.

In JCL :

...........

............

//sysin dd *

001

aaaa

330000

/*

If you write an MVC statement with an equated value as the

sending operand, then the assembler will try to resolve that

operand value as a base and displacement, it will not

necessarily throw an error at assembly, but the results at

execution will be unpredictable and may well give rise to a

protection exception.

The point of the MVI statement is that the single byte

sending operand value is assembled as part of the

instruction itself and does not have to be 'fetched' at

execution time, therefore if you are only moving a single

byte of fixed value, then an MVI will be marginally more

efficient than an MVC

ICM means INsert character under mask. its a movement of character under mask bits

eg

ICM R8,B'0110',SRC

Before execution:

R8 ==> 12 34 56 78

SRC ==> AB CD EF 10

After Excecution:

R8 ==> 12 CD EF 78

maximum displacement is 4k i.e 4096 bytes.

if we need to add more than 4096 bytes another base register.

1) If there is any updates in the Macros regarding the

structure change or addition/removal of byte, then you need

to Promote the macro to Live first.

2) Reassemble your codes against the Live Macros.

3) Raise ELAS for the Codes to go to production.

4)Promote the codes to production.

VSAM file can be accessed through an Assembler application

program by using assembler macros RPL, ACB

S0C7 occurs when the data exception occurs.They are many

ways to produce S0C7

1)Move non numeric data to a numeric feild

2)compare junk data with a numeric feild

3) Use a non numeric data in COMPUTE statement

4) Refer to the occurence in a table beyond the occurs time

with SSRANGE not checked in complier options

Registers are part of the CPU logic and should not be

confused with memory real or virtual. The question is

about as sensical as asking where the uterus resides in a

man. Also, general purpose registers 0--16 are an

entirely different breed that the floating point

registers. As for the numbering, a decision made by the

manufacturer's design people.

As this is mainframe assembler section, this is a trick

question - there is no JMPNZ opcode for mainframe (recently

added JNZ with relative addressing in the z/800 and later,

but no JMPNZ) and the mainframe has no RET instruction

(there is a PR to return from a cross address space or PC

"call" statement) and the mainframe has no accumulator, ADB

opcode, or B register.

There are two possible scenarios:

1) This is a classroom quesiton where you are expected to

do some research on your own, and not ask someone in the

cloud for the exact answer.

2) The question is too vague, and would require a full

essay to answer. Please be more specific.

We can certainly use the MVC instruction to move the pack data to another pack field.

You will need to open de file SYSIN via a DCB and read the

data via GET commands. The data in the PARM field is passed

via register 1. Any dataset you want to use in Assembler

you will need to open. There are no automatic allocation.

This is a vague two-part question.

1) You can round by adding .5

2) Adds 5 to WKUR, but it had better be a valid packed field, and not just a label.

There are 16 registers, and ALL can be used as a base EXCEPT

for register 0, so the answer is AT LEAST 15. AT LEAST is

specified here because in any section of code, you can

"re-use" a previous base register once you are no longer

within the original address range ("scope") of that

particular base register. By re-using the registers, you can

have base registers that will cover ALL of the memory in the

machine - but not all at once - you have to "bite off" 15

base reg-at-a-time chunks of memory (all addressable memory

does not have to be contiguous - it can be scattered around

memory in 4K pieces).

By convention, general purpose register 1 will have the

address of the parameter list. The list will be a list of

pointers (addresses) to individual parameters. The CALL

macro does this, but you can bypass the CALL macro and be

creative on how you set up the parameter list. Don't forget

the parameter must be on a fullword boundary.

START is an assembler directive which has an optional

operand, (0 in your example). This operand acts as the

starting address of the program e.g. PROGNAME START X'3E0'

tells the linkage editor that this program is to be loaded

into main storage at address '3E0' in hex. This explanation

answers all your questions.