************Simpletron 3************

Computer Simulation Simpletron3 simulates a computer executing a program written in SML, a fakey assembly language. The user can enter a program, then watch the computer assemble and execute each statement. Programs can manipulate integer data from -9999 to +9999 with the five operations: addition, subtraction, multiplication, division, and exponentiation. During execution certain fatal errors are detected: attempts to divide by zero, accumulator overflow, invalid operation codes. These errors will produce an error message and a memory dump; the memory will also be displayed after a valid program is executed. Other careless user errors will cause the applet to crash. Simpletron3 has a RAM of 100 addresses from 00 to 99. SML: the Language SML: the Programs Sim3: the Computer [Frankie's Applet Forum] [JAVA Applets]

SML: an Assembly Language The JAVA applet "Simpletron3" simulates a computer executing a program in assembly language: the language is SML. Each SML instruction contains four digits.The first two digits represent the operation code; the second digit pair is the RAM address.
Simpletron3 has a 100 word memory (00...99). All arithmetic instructions leave their results in the accumulator.

OP CODE 10## 11## 20## 21## 30## 31## 32## 33## 34## 40## 41## 42## 43##

MEANING Read a word from the keyboard into a specific memory location. Write a word from a specific memory location to the screen. Load a word from a specific memory location to the accumulator. Store a word from the accumulator to specific memory location. Add a word from a specific memory location to the accumulator. Subtract a word from a specific memory location to the accumulator. Multiply a word from a specific memory location to the accumulator. Divide a word from a specific memory location to the accumulator. Raise a word in the accumulator to a power from a specific memory location. Branch to specific location in memory. Branch to a specific location in memory if accumulator is negative. Branch to a specific location in memory if accumulator is zero. Halt

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Sample Programs

Program: reads two integers; determines and prints the larger. 00  1009  Read A 01  1010  Read B 02  2009  Load A 03  3110  Subtract B 04  4107  if Acc<0 goto 07 05  1109  else Print A 06  4300 07  1110  Print B 08  4300 09  A 10  B

Program: reads integer list, calculates and prints average. 1050  Read C; (counter-length of list) 1052  Read N; (list item,"0" ends list) 2052 4211 2051 3050 2151 2052 3053 2153 4001 2053 3351 2154 1154 4300

Your program here. Write a program in SML and send to Frankie: Webmaster@iXoraWebDesign for posting.

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