2024-04-12

Friday, April 12th, 2024

Two of man's basic needs are to love and to share. Both of these needs are satisfied in greater or lesser degree by friendship.

— Mother Angelica

Docker Desktop rants

I hate Docker Desktop + Dev Containers on Windows. There’s always some kind of error when I start a dev container. Well, sometimes you can fix it by restarting the machine once or twice. One particularly confusing problem I encountered seemed to be an issue where Docker Desktop would sometimes turn off WSL integration (e.g., when I run wsl --shutdown without stopping DD first), and upon the next restart VSC would try to connect to a container or volume that doesn’t exist (because DD is no longer using the WSL Docker socket). Sometimes I would accidentally create a container in Windows and not WSL, and it means I would after to turn off WSL integration to access the container. What a cursed piece of software.

• A year with Spectre: a V8 perspective

ECS154A Lecture: muxes cont’d

$$y=\neg s\cdot x_0+s\cdot x_1$$

• n-to-1 k-bit mux: a mux that turns $n$ $k$-bit inputs into 1 $k$-bit output (e.g., the above is a 2-to-1 1-bit mux)

Here’s a four to one mux

How do we convert it to a boolean expression?

Match each combination of s (select) bits with $x_i$

$$y=\overline{s_1}\overline{s_0}{x}_0+\overline{s_1}{s}_0{x}_1+s_1\overline{s_0}{x}_2+s_1{s}_0{x}_3$$

The truth table is therefore:

$s_1$	$s_0$	$y$
0	0	$x_0$
0	1	$x_1$
1	0	$x_2$
1	1	$x_3$
For a k-bit mux with $k>1$, the $i$-th bit of each input has a dedicated mux to switch the input, so there will be $k$ muxes to make up the bigger mux.

ECS154A Discussion: decoder, clock, PC

• static discipline: all digital electronics are analog electronics that obey a static discipline—there’s an expected range (thresholds) of voltage for high and low signals, so when an valid input voltage is given, a valid output voltage will result

AND gate?

A	B	Y
0	0	0
0	1	0
1	0	0
1	1	1

We can turn a mux with a programmable logic gate—we can make an ALU out of this.

• A, B, … (the select bits) as inputs
• $x_0$, $x_1$, … are hooked up to either ground or VCC (+5V)

decoder truth table

$A_1$	$A_2$	$x_3$	$x_2$	$x_1$	$x_0$
0	0	0	0	0	1
0	1	0	0	1	0
1	0	0	1	0	0
1	1	1	0	0	0

$$\begin{array}{rl}{x}_0& =\overline{A_1}\overline{A_0}\\ x_1& =\overline{A_1}{A}_0\\ x_2& =A_1\overline{A_0}\\ x_3& =A_1{A}_0\end{array}$$

adder with register that adds on every clock cycle → 2-bit program counter!

• clocked: when clock is high, write to register
• propagation delay: determines how fast the circuit runs (from receiving input to spitting out an output)
  • frequency of computer (CPU) = 1 / propagation delay
  • need to make sure that cycle time is greater than propagation delay, so that the output of a circuit has time to stabilize before they are written.
• clock lives in a separate circuit
• hook the register A’s read port to decoder, and we’ve got some rotating flashing lights (in binary)

SOC001 Discussion: sociological imagination

• levels of analysis
  • macro: large-scale processes/structures
  • meso: between macro & micro (e.g., organizations)
  • micro: smaller-scale
• agency: (micro) capacity of individuals to act and make choices freely
• social structure: (macro) stable relationships between groups that influence actors
• sociological imagination “enables us to grasp history and biography and the relations between the two in society” – C. Wright Mills
  • helps us understand how the micro and macro interconnects—understand how some troubles may extend beyond the immediate social environment
  • interpret recurring personal troubles as social issues that are formed by broader social structures
  • History (societal history) and biography (personal history) cannot be understood independently of each other.
• history → broader social structures → immediate social environment → person
• social fact: ways of acting/thinking/feeling, external to the individual, but can coerce and control the individual, e.g., gender roles
  • Social facts are around us and within us.
    • around us: norms—people have expectations for those around them
    • within us: we internalize such norms to regulate ourselves even without others observing us
• social forces: a type of social fact
  • not deterministic—individuals can still deviate from how the social forces guide us to act

MGT011A Discussion: no notes