{"id":277,"date":"2023-03-08T17:22:57","date_gmt":"2023-03-08T17:22:57","guid":{"rendered":"https:\/\/mrcottle.co.uk\/WP\/?page_id=277"},"modified":"2023-03-09T20:55:11","modified_gmt":"2023-03-09T20:55:11","slug":"little-man-computer-2","status":"publish","type":"page","link":"https:\/\/mrcottle.co.uk\/WP\/little-man-computer-2\/","title":{"rendered":"Little Man Computer"},"content":{"rendered":"\n\n\n


<\/p>\n\n\n\n\n\n

Little Man Computer<\/p>\n\n

Little Man Computer – LMC –<\/span> is a simulator that mimics the modern computer architecture, known as <\/span>von Neumann architecture.<\/span> It was a brainchild of Dr Stuart Madnick, invented in 1965; <\/span><\/p>\n

Since it can model the modern computer, it is still widely used as a teaching tool and should help students understand aspects of the Von Neumann Architecture. <\/span><\/p>\n

This will help students understand the inputs, outputs, control unit, logic unit, memory and the bus connecting it all together. <\/span>
<\/p>\n\n\n

Visit the Little Man Computer simulator and try out your own machine code to see the registers and RAM in operation<\/p>\n

Check out some Little Man Computer code and information<\/p>\n\n\n\n\n

The little man\u2019s instruction set: <\/h6>\n
These are all the instructions the little man can execute.<\/h5>
 <\/h5>

Instruction<\/span><\/p><\/td>

Mnemonic<\/span><\/p><\/td>

Machine Code<\/span><\/p><\/td><\/tr>

Load<\/span><\/p><\/td>

LDA<\/span><\/p><\/td>

5xx<\/span><\/p><\/td><\/tr>

Store<\/span><\/p><\/td>

STA<\/span><\/p><\/td>

3xx<\/span><\/p><\/td><\/tr>

Add<\/span><\/p><\/td>

ADD<\/span><\/p><\/td>

1xx<\/span><\/p><\/td><\/tr>

Subtract<\/span><\/p><\/td>

SUB<\/span><\/p><\/td>

2xx<\/span><\/p><\/td><\/tr>

Input<\/span><\/p><\/td>

INP<\/span><\/p><\/td>

901<\/span><\/p><\/td><\/tr>

Output<\/span><\/p><\/td>

OUT<\/span><\/p><\/td>

902<\/span><\/p><\/td><\/tr>

End<\/span><\/p><\/td>

HLT<\/span><\/p><\/td>

000<\/span><\/p><\/td><\/tr>

Branch if zero<\/span><\/p><\/td>

BRZ<\/span><\/p><\/td>

7xx<\/span><\/p><\/td><\/tr>

Branch if zero or positive<\/span><\/p><\/td>

BRP<\/span><\/p><\/td>

8xx<\/span><\/p><\/td><\/tr>

Branch always<\/span><\/p><\/td>

BRA<\/span><\/p><\/td>

6xx<\/span><\/p><\/td><\/tr>

Data storage<\/span><\/p><\/td>

DAT<\/span><\/p><\/td>

 <\/span><\/p><\/td><\/tr><\/tbody><\/table>

 <\/p>

 <\/p>

 <\/p>

 <\/p>

 <\/p>

 <\/p>

 <\/p>

 <\/p>

xx refers to a Mailbox number (Memory Address)<\/span><\/p>

 <\/p>

 <\/span>Example (Using Machine Code)<\/span><\/strong><\/p>

Address<\/strong><\/p><\/td>

Instruction<\/strong><\/p><\/td>

What it does:<\/strong><\/p><\/td><\/tr>

Mnemonic<\/strong><\/p><\/td>

Machine Code<\/strong><\/p><\/td><\/tr>

00<\/span><\/p><\/td>

INP<\/span><\/p><\/td>

901<\/span><\/p><\/td>

Input a number and put it in the calculator<\/p><\/td><\/tr>

01<\/span><\/p><\/td>

STA 99<\/span><\/p><\/td>

399<\/span><\/p><\/td>

Store the number in the calculator in memory slot 99<\/p><\/td><\/tr>

02<\/span><\/p><\/td>

INP<\/span><\/p><\/td>

901<\/span><\/p><\/td>

Input a number and put it in the calculator<\/p><\/td><\/tr>

03<\/span><\/p><\/td>

ADD 99<\/span><\/p><\/td>

199<\/span><\/p><\/td>

Add the number in memory slot 99 to the number in the calculator<\/p><\/td><\/tr>

04<\/span><\/p><\/td>

OUT<\/span><\/p><\/td>

902<\/span><\/p><\/td>

Output the number which is now in the calculator<\/p><\/td><\/tr>

05<\/span><\/p><\/td>

HLT<\/span><\/p><\/td>

000<\/span><\/p><\/td>

Halt<\/p><\/td><\/tr><\/tbody><\/table>\n\n\n\n\n\n

Lesson Resources<\/p>\n\n\n\n


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