A TRANSLATOR OF MUSS 80 FOR CYBER 72 translator of muss 80 for cyber 72

Abstract

Language translation이라는 말은 넓은 의미에서 볼때, 한 컴퓨터 (Source system 이라함)에서 사용되느 언어로 된 프로 그램 (Source program)을 다른 컴퓨터 (Object system)에 직접 수행 시켜 같은 결과를 얻도록 하는 과정을 의미 한다. 이러한 translation 방법으로는 Translation, Interpretation, Simulation, 마지막으로 Emulation이 있다. 이 논문에서는 첫 번째의 방법으로 고안된 M-C Translator가 소개된다. Source language 로느 43개의 instruction 으로된 MSS 80 assembly language (UNIVAC Solid State S-4 assembly system 의 subsystem)가, Object language 로는 CDC DYBER COMPASS가 사용된다. M-C Translator 자체는 Fortran 으로 되어 있으며, 7개의 COMPASS Subroutime 과 35개의 macro 가 준비 되었다. 각각의 executable 한 source instruction은 한 개의 macro와 대응하고 있어서, object program 내에서의 source instruction은 macro instruction이 되는 것이다. Subroutime 들은 주로 object system 내에서 source data를 source system 에서와 같은 형태로 보존하고 다루기 위해 사용된다. Source instruction을 첫째, translate 할 필요가 없는, 즉 ,object system 내에서는 전혀 의미를 가지지도 못하며 또한 translate 안했다 하더라도 program의 수행에나 결과에는 아무런 영향도 주지 못하는 instruction 과 꼭 translation 이 요구되는 instruction, 둘째, operand address portion 은 사용하지 않고 next address 만을 지적하고 있는 instruction 과 두 address portion 이 모두 요구되는 instruction, 셋째, overflow condition 을 가지는 instruction 과 overflow condition과는 관계가 없는 instruction 의 세가지 각도에서 분류하여 처리 하였다. 각 source instruction의 의미가 어떻게 해당 macro 내에서 반영되고 있는지가 중요하다. M-C Translation 상에서의 문제점과, 특별히 translate 하기 어려웠던 점과 그 처리, 또한 비교적 쉬웠던 점 등이 나열된다. Test program 으로느 2개가 보여지며, source machine 에서의 결과와 object machine 에서의 결과가 일치함을 볼 수 있다. ;Language translation refers in the plobal meaning to the process whereby a program which is executable in one computer can be executed in another computer directly to obtain the same result. There are four different ways of approaching translation. The first way is Translation by a Translator or a Compiler. the second way is Interpretation, the third way is SimulatIon, the last way is EmulatIon. This paper introduces the M-C Translator which was desipned as the first way of translatIon. The MUSS 80 language ( the subsystem of the UNIVAO Solid State 80 S-4 assembly languae system ) was chosen as the source language which includes fortythree instructions, using the CYBER COMPASS as the object language. The M-C translabor is a two pass translator and written in Fortran Extended lanpuape. For this M-C Translation, seven COMPASS subroutines and a set of thirty-five macros were prepared. Each exectable source instruction corresponds to a macro, so it will be a macro instruction within the object program Subroutines are used to retain and handle the source data representatlon the same way in the object propram as in the source system , and used to convero the decimal source data into the equivalent binary number, the binary result into the equvalent USS 80 dipit, before and after arithmetic operation. The source instructions can be classitfied three way. FIrst, there are some instructions which are meaningless in the object system and are therefore unnecessary to tyanslate, and the remaining instructions should be translated. Second, there are some Instructions which indicate only the next address, not the operand address and the remaining instructions are required to indicate duaI address portions. Third, there are three instructions whIch have overflow coditions, which are lacking in the remaining instructions. The construction and functIons of the M-C Translator, the subroutines, macros are explained. The problems , difficulties and the method of solving them, and easier features on this translation are analysed. For test proprams, an example of interchange sorting program and uniformly distributed random number generator by multiplicative congruential method were chosen to be presented here. So we can see that the results from both source and object machines are the same. The study of how to save memory and time wilI be continued