Autosave: 2024-10-28 15:52:09
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@ -0,0 +1,10 @@
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---
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tags: [world-wide-web, internet]
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created: Monday, October 28, 2024
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---
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# 3f1b9fe5_motivation_Berners_Lee
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TBL describes his motivation in creating the WWW as the desire to marry two
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separate concepts/technologies: hypertext and the Internet, after both had come
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of age.
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@ -0,0 +1,22 @@
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---
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tags: [internet, ARPANET, ARPA]
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created: Monday, October 28, 2024
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---
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# 4a3dc316_key_figures_ARPANET
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- [Paul Baran](385af4b4_Baran_distributed_networks.md) for his work at RAND on
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distributed networks as an alternative to the extant
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centralised/de-centralised phone networks.
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- Donald Davies at the UK Physical Laboratory for developing ideas on
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#packet-switching, similar to but derived independently of Baran's work.
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- Bob Kahn as the principle designer of the ARPANET, who with Vint Cerf, wrote
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the TCP/IP protocols. Became director of the Information Processing Techniques
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Office within ARPA/DARPA.
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- Vint Cerf was head of the International Networking Group and worked on the
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Network Control Protocol (the first protocol for packet switching using the
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IMPs). Later joined up with Kahn on TCP/IP and the network of packet-switching
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networks (early internet).
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@ -0,0 +1,56 @@
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---
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tags: [internet, ARPANET]
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created: Sunday, October 27, 2024
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---
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# 4da22434_from_ARPANET_to_Internet
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By the mid-1970s many additional computer networks had emerged which also used
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#packet-switching.
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It was the success of ARPANET as a "proof of concept" for packet-switching that
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led to these additional networks being created in other countries and contexts.
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Some used different modes of transmission than the #ARPANET's phone-wire based
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system such as radio waves and satellites. However this created a problem: these
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networks were siloed from each other and a bridge was needed to connect them.
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Those working on the ARPANET steering committee (the Information Processing
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Techniques Office (IPTO) within ARPA/DARPA) began to discuss what they called a
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"concatenated network" or "CATENET" that would connect these different networks
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together. Thus emerged the idea of a _network of networks_ or _inter-network_.
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For this to work it would be necessary to construct "gateways": routing
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computers that would hand-off messages from one network to another.
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This required a new protocol because the Network Control Protocol was only
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designed to work _within_ the ARPANET with its IMPs. Unlike the IMPs, the
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gateways would not be responsible for reconstituting packets or ensuring
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reliability, this would be shifted to the hosts. The protocol was the
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[Transmission Control Protocol/Internet Protocol](Internet_Layer_of_Internet_Protocol.md).
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TCP would be responsible for packet assembly and disassembly and IP for routing.
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The "common language" of TCP/IP and the growth in networks in addition to the
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ARPANET is what formed the Internet. Different commercial groups and research
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enterprises inaugurated their own networks and, one-by-one, they adopted TCP and
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became accessible to each other.
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As the ARPANET was retired, its individual sites either became nodes within the
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Internet or they split off into sub-networks such as MILNET (which was part of
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the ARPANET retained for classified military communication). The IMPs were
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retired in favour of TCP/IP routers.
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_The ARPANET in 1973_
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_The ARPANET as part of an inter-network 1977_
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_ The ARPANET in 1977_
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_The Internet in 1984_
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|
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@ -0,0 +1,24 @@
|
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---
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||||
tags: [internet, ARPANET]
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created: Sunday, October 27, 2024
|
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---
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# 82f9c228_dissolution_of_ARPANET
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By 1984, the US military became concerned about the expansion of the ARPANET and
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its growing non-military applications (see the film _War Games_ released in
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1983!). They split the network into the _ARPANET_ for academic research and the
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_MILNET_ for non-civilian users where transmission was encrypted and protected.
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Throughout the 1980s, the US National Science Foundation began promoting private
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networks that used the ARPANET as their _backbone_. (Private in the sense of not
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publicly-funded.)
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Later, these became commercial and
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[subscription-based](cfbef1c4_web_precursors.md). A plethora of ..._NETS_ grew
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up (NSFNET, USENET, CSNET, TELENET etc.), all based on #packet-switching, the
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ARPANET nodes as the backbone and [TCP/IP](Link_Layer_of_Internet_Protocol.md)
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host communication.
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These networks, although accessible to the public through subscriptions,
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remained unwieldy and inconsistent to access until the Web.
|
|
@ -5,8 +5,7 @@ tags: [CPU]
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# Fetch, decode, execute, store
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_Fetch, decode, execute_ is the operating cycle of the CPU. We will run through
|
||||
how this works with reference to the
|
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[CPU architecture](CPU_architecture.md).
|
||||
how this works with reference to the [CPU architecture](CPU_architecture.md).
|
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## Fetch
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@ -57,8 +56,7 @@ to determine which of its circuits should be used for processing.
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Now the command will be executed. The operand is copied to the Memory Address
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Register and then passed to the Memory Data Register and the command is carried
|
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out by the ALU. The activities of ALU are covered in
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[CPU Architecture](CPU_architecture.md#arithmetic-logic-unit)
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and the notes on
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[CPU Architecture](CPU_architecture.md#arithmetic-logic-unit) and the notes on
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[Logic Gates](Logic_gates.md).
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## Store
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@ -73,8 +71,6 @@ specify where to store the result.
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- Data is stored differently depending on the instruction.
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- If the instruction is iterative (e.g. adding two numbers and then multiplying
|
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by another number), the instruction will tell the CPU to store the interim
|
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first value in the CPU's
|
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[registers](CPU_architecture.md#registers). As
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these are part of the CPU, the data can be retrieved more readily. If the
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value is not expected to be used again immediately, it goes to the DRAM or
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harddisk.
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first value in the CPU's [registers](CPU_architecture.md#registers). As these
|
||||
are part of the CPU, the data can be retrieved more readily. If the value is
|
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not expected to be used again immediately, it goes to the DRAM or harddisk.
|
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@ -13,26 +13,30 @@ computer science.
|
|||
|
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|
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|
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**Build ID:** 0368f5e0-e5f8-46f2-9cd3-c028c04a15d1
|
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**Build ID:** 8b09146b-ecca-49b4-bbdb-d619b5566ef4
|
||||
|
||||
**Published:** Fri 25 Oct 2024 13:28:54
|
||||
**Published:** Mon 28 Oct 2024 15:52:07
|
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|
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### Recent edits
|
||||
|
||||
- [[4da22434_from_ARPANET_to_Internet]]
|
||||
- [[3f1b9fe5_motivation_Berners_Lee]]
|
||||
- [[4a3dc316_key_figures_ARPANET]]
|
||||
- [[82f9c228_dissolution_of_ARPANET]]
|
||||
- [[Fetch_decode_execute]]
|
||||
- [[Secrets_or_env_vars_in_AWS]]
|
||||
- [[Working_with_directories_in_Python]]
|
||||
- [[File_CRUD_operations_in_Python]]
|
||||
- [[File_operations_in_Python]]
|
||||
- [[Reading_files_in_Python]]
|
||||
- [[With_open_in_Python]]
|
||||
- [[Writing_to_files_in_Python]]
|
||||
- [[Error_handling_in_Python]]
|
||||
- [[File_system_error_handling_in_Python]]
|
||||
|
||||
|
||||
### All notes (475)
|
||||
### All notes (479)
|
||||
|
||||
- [[385af4b4_Baran_distributed_networks]]
|
||||
- [[3f1b9fe5_motivation_Berners_Lee]]
|
||||
- [[4a3dc316_key_figures_ARPANET]]
|
||||
- [[4da22434_from_ARPANET_to_Internet]]
|
||||
- [[653c0b1d_host_protocols_of_ARPANET]]
|
||||
- [[82f9c228_dissolution_of_ARPANET]]
|
||||
- [[861cc26e_ARPA_origins]]
|
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- [[API_Gateway]]
|
||||
- [[AWS_CLI]]
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10
zk/3f1b9fe5_motivation_Berners_Lee.md
Normal file
|
@ -0,0 +1,10 @@
|
|||
---
|
||||
tags: [world-wide-web, internet]
|
||||
created: Monday, October 28, 2024
|
||||
---
|
||||
|
||||
# 3f1b9fe5_motivation_Berners_Lee
|
||||
|
||||
TBL describes his motivation in creating the WWW as the desire to marry two
|
||||
separate concepts/technologies: hypertext and the Internet, after both had come
|
||||
of age.
|
22
zk/4a3dc316_key_figures_ARPANET.md
Normal file
|
@ -0,0 +1,22 @@
|
|||
---
|
||||
tags: [internet, ARPANET, ARPA]
|
||||
created: Monday, October 28, 2024
|
||||
---
|
||||
|
||||
# 4a3dc316_key_figures_ARPANET
|
||||
|
||||
- [Paul Baran](385af4b4_Baran_distributed_networks.md) for his work at RAND on
|
||||
distributed networks as an alternative to the extant
|
||||
centralised/de-centralised phone networks.
|
||||
|
||||
- Donald Davies at the UK Physical Laboratory for developing ideas on
|
||||
#packet-switching, similar to but derived independently of Baran's work.
|
||||
|
||||
- Bob Kahn as the principle designer of the ARPANET, who with Vint Cerf, wrote
|
||||
the TCP/IP protocols. Became director of the Information Processing Techniques
|
||||
Office within ARPA/DARPA.
|
||||
|
||||
- Vint Cerf was head of the International Networking Group and worked on the
|
||||
Network Control Protocol (the first protocol for packet switching using the
|
||||
IMPs). Later joined up with Kahn on TCP/IP and the network of packet-switching
|
||||
networks (early internet).
|
56
zk/4da22434_from_ARPANET_to_Internet.md
Normal file
|
@ -0,0 +1,56 @@
|
|||
---
|
||||
tags: [internet, ARPANET]
|
||||
created: Sunday, October 27, 2024
|
||||
---
|
||||
|
||||
# 4da22434_from_ARPANET_to_Internet
|
||||
|
||||
By the mid-1970s many additional computer networks had emerged which also used
|
||||
#packet-switching.
|
||||
|
||||
It was the success of ARPANET as a "proof of concept" for packet-switching that
|
||||
led to these additional networks being created in other countries and contexts.
|
||||
Some used different modes of transmission than the #ARPANET's phone-wire based
|
||||
system such as radio waves and satellites. However this created a problem: these
|
||||
networks were siloed from each other and a bridge was needed to connect them.
|
||||
|
||||
Those working on the ARPANET steering committee (the Information Processing
|
||||
Techniques Office (IPTO) within ARPA/DARPA) began to discuss what they called a
|
||||
"concatenated network" or "CATENET" that would connect these different networks
|
||||
together. Thus emerged the idea of a _network of networks_ or _inter-network_.
|
||||
|
||||
For this to work it would be necessary to construct "gateways": routing
|
||||
computers that would hand-off messages from one network to another.
|
||||
|
||||
This required a new protocol because the Network Control Protocol was only
|
||||
designed to work _within_ the ARPANET with its IMPs. Unlike the IMPs, the
|
||||
gateways would not be responsible for reconstituting packets or ensuring
|
||||
reliability, this would be shifted to the hosts. The protocol was the
|
||||
[Transmission Control Protocol/Internet Protocol](Internet_Layer_of_Internet_Protocol.md).
|
||||
TCP would be responsible for packet assembly and disassembly and IP for routing.
|
||||
|
||||
The "common language" of TCP/IP and the growth in networks in addition to the
|
||||
ARPANET is what formed the Internet. Different commercial groups and research
|
||||
enterprises inaugurated their own networks and, one-by-one, they adopted TCP and
|
||||
became accessible to each other.
|
||||
|
||||
As the ARPANET was retired, its individual sites either became nodes within the
|
||||
Internet or they split off into sub-networks such as MILNET (which was part of
|
||||
the ARPANET retained for classified military communication). The IMPs were
|
||||
retired in favour of TCP/IP routers.
|
||||
|
||||
_The ARPANET in 1973_
|
||||
|
||||

|
||||
|
||||
_The ARPANET as part of an inter-network 1977_
|
||||
|
||||

|
||||
|
||||
_ The ARPANET in 1977_
|
||||
|
||||

|
||||
|
||||
_The Internet in 1984_
|
||||
|
||||

|
24
zk/82f9c228_dissolution_of_ARPANET.md
Normal file
|
@ -0,0 +1,24 @@
|
|||
---
|
||||
tags: [internet, ARPANET]
|
||||
created: Sunday, October 27, 2024
|
||||
---
|
||||
|
||||
# 82f9c228_dissolution_of_ARPANET
|
||||
|
||||
By 1984, the US military became concerned about the expansion of the ARPANET and
|
||||
its growing non-military applications (see the film _War Games_ released in
|
||||
1983!). They split the network into the _ARPANET_ for academic research and the
|
||||
_MILNET_ for non-civilian users where transmission was encrypted and protected.
|
||||
|
||||
Throughout the 1980s, the US National Science Foundation began promoting private
|
||||
networks that used the ARPANET as their _backbone_. (Private in the sense of not
|
||||
publicly-funded.)
|
||||
|
||||
Later, these became commercial and
|
||||
[subscription-based](cfbef1c4_web_precursors.md). A plethora of ..._NETS_ grew
|
||||
up (NSFNET, USENET, CSNET, TELENET etc.), all based on #packet-switching, the
|
||||
ARPANET nodes as the backbone and [TCP/IP](Link_Layer_of_Internet_Protocol.md)
|
||||
host communication.
|
||||
|
||||
These networks, although accessible to the public through subscriptions,
|
||||
remained unwieldy and inconsistent to access until the Web.
|
|
@ -5,8 +5,7 @@ tags: [CPU]
|
|||
# Fetch, decode, execute, store
|
||||
|
||||
_Fetch, decode, execute_ is the operating cycle of the CPU. We will run through
|
||||
how this works with reference to the
|
||||
[CPU architecture](CPU_architecture.md).
|
||||
how this works with reference to the [CPU architecture](CPU_architecture.md).
|
||||
|
||||
## Fetch
|
||||
|
||||
|
@ -57,8 +56,7 @@ to determine which of its circuits should be used for processing.
|
|||
Now the command will be executed. The operand is copied to the Memory Address
|
||||
Register and then passed to the Memory Data Register and the command is carried
|
||||
out by the ALU. The activities of ALU are covered in
|
||||
[CPU Architecture](CPU_architecture.md#arithmetic-logic-unit)
|
||||
and the notes on
|
||||
[CPU Architecture](CPU_architecture.md#arithmetic-logic-unit) and the notes on
|
||||
[Logic Gates](Logic_gates.md).
|
||||
|
||||
## Store
|
||||
|
@ -73,8 +71,6 @@ specify where to store the result.
|
|||
- Data is stored differently depending on the instruction.
|
||||
- If the instruction is iterative (e.g. adding two numbers and then multiplying
|
||||
by another number), the instruction will tell the CPU to store the interim
|
||||
first value in the CPU's
|
||||
[registers](CPU_architecture.md#registers). As
|
||||
these are part of the CPU, the data can be retrieved more readily. If the
|
||||
value is not expected to be used again immediately, it goes to the DRAM or
|
||||
harddisk.
|
||||
first value in the CPU's [registers](CPU_architecture.md#registers). As these
|
||||
are part of the CPU, the data can be retrieved more readily. If the value is
|
||||
not expected to be used again immediately, it goes to the DRAM or harddisk.
|
||||
|
|