madd@world.std.com (jim frost) (10/26/89)
In article <8910251508.AA29374@brazos.rice.edu> IBM 370 Assembly Programming Discussion List <ASM370%UCF1VM.BITNET@ricevm1.rice.edu> writes: |If you already know about machine-level programming, then probably the |best reference book for 370 machine-level is Principles of Operation. Yes and no. It's certainly the most accurate, but some of the instruction descriptions leave much to be desired. For example, if you happen to have POO (I always liked that abbreviation :-) handy, look up "TR" and see if you the description gives you any clue as to what the command is actually intended for. It's perfectly accurate, just not what you'd expect. TR is my favorite fractured description in POO; what's yours? jim frost software tool & die madd@std.com
madd@CS.BU.EDU (jim frost) (10/26/89)
In article <8910251508.AA29374@brazos.rice.edu> IBM 370 Assembly Programming Discussion List <ASM370%UCF1VM.BITNET@ricevm1.rice.edu> writes: |If you already know about machine-level programming, then probably the |best reference book for 370 machine-level is Principles of Operation. Yes and no. It's certainly the most accurate, but some of the instruction descriptions leave much to be desired. For example, if you happen to have POO (I always liked that abbreviation :-) handy, look up "TR" and see if you the description gives you any clue as to what the command is actually intended for. It's perfectly accurate, just not what you'd expect. TR is my favorite fractured description in POO; what's yours? jim frost software tool & die madd@std.com
A01MES1@NIU.BITNET (Michael Stack) (10/26/89)
> Yes and no. It's certainly the most accurate, but some of the > instruction descriptions leave much to be desired. For example, if > you happen to have POO (I always liked that abbreviation :-) handy, > look up "TR" and see if you the description gives you any clue as to > what the command is actually intended for. It's perfectly accurate, > just not what you'd expect. > > TR is my favorite fractured description in POO; what's yours? OK, I give up. What's the gimmick? Here's what my POO (370) says: "The bytes of the first operand are used as eight-bit arguments to reference a list designated by the second-operand address. Each function byte selected from the list replaces the corresponding argument in the first operand." That's only the first paragraph, but the rest of the description is peripheral rather than central. Perhaps I'm being dense here, but this IS just exactly what I expect; that's what TR does. If you are looking for an indication of what the instruction can be used for, following the description are some programming notes which include suggestions of how to use TR. In addition, there is an example (such as it is) which further describes purposes to which TR might be put. This said, I would suggest that POO be used only in conjunction with a text, not by itself (stand-alone?). It is a good reference, but like many IBM manuals, "you can't read it until you know what it says." Michael Stack Northern Illinois University