Assembler Language differs from all of the other languages such as COBOL, PL/I, RPG etc. It resembles the actual machine-instructions that you are likely to find on a Mainframe. Assembler-Language is a Low-level language. For performing a complex-task, you need to write several instructions. On the other hand, COBOL and other modern platforms such as Java or C# are High-Level Languages(HLL). In these languages, its possible to represent a complex task by one single-instruction.
COBOL looks more English-like. Its quite verbose. Writing a program in Assembler requires a different line-of-thinking, different thought pattern. Unlike COBOL, Assembler-Language statements don’t terminate with a period. Assembler language commands don’t even come close to English.
Alright, now let's keep this between you, me and the gatekeeper – COBOL Programs are actually transformed to Machine code. In fact, you can see the equivalent Machine-code corresponding to your COBOL-Program, for yourself when you run the Compiler IGYCRCTL with the PARM='LIST' Option. You would find that 1 COBOL Instruction generates several Machine-Instructions. By contrast, 1 Assembler-Instruction generates only one single Machine-Instruction. Guess what, you need to code several lines-of-Assembler to achieve the same effect as one line-of-COBOL.
Another paradigm-shift of thinking is needed, with the order of operands. COBOL does a MOVE A TO B, or ADD 1 TO COUNTER, take the first thing and do something to the second. In Assembler, you’d have to code MVC B,A or AP COUNTER,=P'1', the second operand normally does something on the first.
COBOL Programs are broken down into divisions, sections and para's – its strictly organized and structured. In Assembler, you just start coding. You decide your own custom-organization and enforce it, follow it throughout the program.
COBOL looks more English-like. Its quite verbose. Writing a program in Assembler requires a different line-of-thinking, different thought pattern. Unlike COBOL, Assembler-Language statements don’t terminate with a period. Assembler language commands don’t even come close to English.
Alright, now let's keep this between you, me and the gatekeeper – COBOL Programs are actually transformed to Machine code. In fact, you can see the equivalent Machine-code corresponding to your COBOL-Program, for yourself when you run the Compiler IGYCRCTL with the PARM='LIST' Option. You would find that 1 COBOL Instruction generates several Machine-Instructions. By contrast, 1 Assembler-Instruction generates only one single Machine-Instruction. Guess what, you need to code several lines-of-Assembler to achieve the same effect as one line-of-COBOL.
Another paradigm-shift of thinking is needed, with the order of operands. COBOL does a MOVE A TO B, or ADD 1 TO COUNTER, take the first thing and do something to the second. In Assembler, you’d have to code MVC B,A or AP COUNTER,=P'1', the second operand normally does something on the first.
COBOL Programs are broken down into divisions, sections and para's – its strictly organized and structured. In Assembler, you just start coding. You decide your own custom-organization and enforce it, follow it throughout the program.
