vault backup: 2022-09-22 12:09:01

content/notes/15-file-systems.md

@@ -4,6 +4,9 @@ aliases:
 tags: 
 - cosc204
 - lecture
+sr-due: 2022-09-25
+sr-interval: 3
+sr-ease: 250
 ---
 
 # what is a file (LINUX)

content/notes/16-device-drivers.md

@@ -0,0 +1,47 @@
+---
+title: "16-device-drivers"
+aliases: 
+tags: 
+- lecture
+- cosc204
+---
+
+# Device controller and driver
+driver Defn:  a special kernel module that contrls the operations of a device with the device specific information
+controller Defn: a hardware unit on a device that can know and control a devices status or behaviour, which communicates with the CPU via a driver
+
+![device drivers and controllers diagram|300](https://i.imgur.com/m0nxDqa.png)
+
+# Types of IO devices
+- character stream vs block
+- swqeuential vs random access
+- synchronous vs async
+- sharable or dedicated
+
+OS provides a consistent interface for them in the `/dev` folder (unix systems). e.g., ramdisk device is name `/dev/memdrv`. each device has a file under `/dev` that can be handled with file operations read()/write()
+
+## block devices
+commands (sent from device driver to device controller)
+- read block
+- write block
+- seek block (for random access block devices)
+
+the sequence of read/write requests can (should) be optimized
+
+## character devices
+- commands
+	- get char
+	- put char
+
+also support buffering (accepting keyboard input line by line) and editing of buffers (e.g., spcial treatement of backspace character)
+
+# IO models
+
+IO system calls use different IO models
+- blocking - when a proccess needs IO input it waits to recieve it before c
+- non blocking
+- async
+
+# IO scheduling and buffering
+
+# UI for IO devices

content/notes/comp-210.md

@@ -37,3 +37,4 @@ No final exam
 - [13-pen-testing-2](notes/13-pen-testing-2.md)
 - [15-policies-standards-practices](notes/15-policies-standards-practices.md)
 - [16-cloud-security](notes/16-cloud-security.md)
+- [17-ML-in-IA-1](notes/17-ML-in-IA-1.md)

content/notes/cosc-203.md

@@ -36,6 +36,7 @@ tags:
 - [10-routes-controllers](notes/10-routes-controllers.md)
 - [11-view-templates](notes/11-view-templates.md)
 - [12-ethics-and-computing](notes/12-ethics-and-computing.md)
+- [13-databases-1](notes/13-databases-1.md)
 
 # Archive
 

content/notes/cosc-204.md

@@ -43,7 +43,8 @@ tags:
 - [12-pointers-to-routines](notes/12-pointers-to-routines.md)
 - [13-OS-intro](notes/13-OS-intro.md)
 - [14-processes-and-system-calls](notes/14-processes-and-system-calls.md)
-
+- [15-file-systems](notes/15-file-systems.md)
+- [16-device-drivers](notes/16-device-drivers.md)
 # Archive
 
 # Info