Learning Objectives

Understand data represenatation ( ASCII and UNICODE)
Explain memory hierarchy, memory organization, memory storage devices and cache memory
All students can draw block diagram of the Von Nuemann model
Understand Instruction execution through instruction cycles and also interrupt handling

Teacher show that 8 bits can represtent 256 things... ( 255 highest number, but if all zero then can repreneset 256 ( 2 powe 8 ) ASCII stands for American Standard Code for Information Interchange

Learning Objectives

Understand Boolean operators : AND, OR, NOT, NAND, NOR and XOR
Able to construct simple truth tables with no more than 3 inputs
Construct logic diagrams based on no more than 3 inputs

Homework click here ( )

Conditional statements and logic operators practice ( Computational thinking )

Absolute will return the absolut value example abs(-21) will return 21

Fetch - Decode - Execute - Store Cycle

My resources click here

Link to Little Man Computer Click Here

Type in these example instructions to that will add 2 numbers: INP, STA 99, INP, ADD 99, OUT, HLT

The instructions are held in RAM / Memory

The instruction register holds the instruction code exampe 3 to store the address regsiter holds the address to store what is held in the accumulator.

Here is the code to subtract 2 numbers , try it out

INP
STA A
INP
STA B
LDA A
SUB B
OUT
HLT
A DAT
B DAT

Little Man Computer references

Numeric code	Mnemonic code	Instruction	Description
1xx	ADD	ADD	Add the value stored in mailbox xx to whatever value is currently on the accumulator (calculator). Note: the contents of the mailbox are not changed, and the actions of the accumulator (calculator) are not defined for add instructions that cause sums larger than 3 digits.
2xx	SUB	SUBTRACT	Subtract the value stored in mailbox xx from whatever value is currently on the accumulator (calculator). Note: the contents of the mailbox are not changed, and the actions of the accumulator are not defined for subtract instructions that cause negative results - however, a negative flag will be set so that 8xx (BRP) can be used properly.
3xx	STA	STORE	Store the contents of the accumulator in mailbox xx (destructive). Note: the contents of the accumulator (calculator) are not changed (non-destructive), but contents of mailbox are replaced regardless of what was in there (destructive)
5xx	LDA	LOAD	Load the value from mailbox xx (non-destructive) and enter it in the accumulator (destructive).
6xx	BRA	BRANCH(unconditional)	Set the program counter to the given address (value xx). That is, value xx will be the next instruction executed.
7xx	BRZ	BRANCH IF ZERO (conditional)	If the accumulator (calculator) contains the value 000, set the program counter to the value xx. Otherwise, do nothing. Note: since the program is stored in memory, data and program instructions all have the same address/location format.
8xx	BRP	BRANCH IF POSITIVE (conditional)	If the accumulator (calculator) is 0 or positive, set the program counter to the value xx. Otherwise, do nothing. Note: since the program is stored in memory, data and program instructions all have the same address/location format.
901	INP	INPUT	Go to the INBOX, fetch the value from the user, and put it in the accumulator (calculator) Note: this will overwrite whatever value was in the accumulator (destructive)
902	OUT	OUTPUT	Copy the value from the accumulator (calculator) to the OUTBOX. Note: the contents of the accumulator are not changed (non-destructive).
0	HLT	HALT	Stop working.
	DAT	DATA	This is an assembler instruction which simply loads the value into the next available mailbox. DAT can also be used in conjunction with labels to declare variables. For example, DAT 984 will store the value 984 into a mailbox.