xerox 19771028 D0 Simulator Operating Instructions free download

File name 19771028_D0_Simulator_Operating_Instructions.pdf

XEROX System Development Division October 28, 1977 XEROX SDD ARCHIVES To: Simulator users I have read and understood Pages _ _ _ _ _To._ _ _ __ From: Crowther Reviewer Date_ _ __ Subject: DO Simulator operating instructions :/I of Pages _ _ Ref .. -r1S.7)1)~ -3 " " Documentation The user of the simulator must be familiar with three other systems which are documented elsewhere: 1) The DO Assembler System, documented on [Maxc]DOASSEM.PUB. 2) The mesa system, documented on [maxc]. 1) The DO itself, soon to be documented on [maxc]??? This memo will assllme that the reader knows how a DO works, presumably from reading the documentation on the processor. Therefore I will casually use terms like the T register, and assume the reader understands their function. If the reader is unfamiliar with mesa, he is advised to get help from an expert in preparing his starting disk; thereafter mesa can be ignored. Getting Started To run the simulator you need a disk with the following modules on it: Mesa.run (renamed runmesa.run if using 10hnsson's exec) Mesa.lmage wmanager.bcd s.bcd s.bcd is on [maxc]s.bcd. 10hnsson's exec is on [maxc]exec.run. All the other files can be found on the mesa directory on maxc. It is also helpful but not necessary to have an installed mesa debugger on the disk. With a debugger, if the system crashes the user gets some clue about what happened. To run the simulator you must start the file s. If usin~ the regular exec type the following (user types the bold characters, system the normal characters): mesa new filename s start filename ESC If using 10hnsson's exec (which I recommend) type: mesa s After a delay for loading, the alto screen comes alive and is waiting for your instructions. In order to understand what to do now, you must realize that there are really three quite separate programs running in the machine at this instant. 1) There is the standard mesa window package. which is documented with the mesa system: it has complete control of the mOllse, and will let YOli move the window(s) on the screen or create and destroy new windows. You can scroll any window in the normal mesa way. 2) There is a DO Simulator, which has a complete simulated state for a DO (without any 1/0). The DO design is documented elsewhere. This simulator has a few features which the real DO lacks: in particular, there is a control register which will start the machine when something is written into it. Depending on whether a ],2, or 3 is written the simulated DO will run for one cycle, one instruction, or forever (