[Coco] Coco crew podcast

Tue May 28 20:31:04 EDT 2024

John,

Topics...

George Boole Jnr.
Boolean vs Binary
Fixed point vs floating point
Analog vs Digital
Slide rule vs soroban or adding machine.

Signed vs unsigned.
If you add two positive numbers and get a negative results then you had an
overflow.
If you add two negative numbers and get a positive results then you had an
overflow.

Key (General knowledge):

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  Mark and Space......: Used in telegraph communications to draw long/short
lines/spaces on a piece of moving paper.
  Mark................: Pen down.
  Space...............: Pen up.
  ....................: I think teletype (TTY) terminals first used
telegraph wires and so mark/space notation
  ....................: continued. TTY uses asynchronous communications
exactly like a UART.
  UART................: Universal Asynchronous Receiver / Transmitter. It
sends out a start-bit, data-bits,
  ....................: parity-bit, stop-bit.
  ....................: Start-bit = Space = +3V to +15V on RS-232 or logic 0
on a UART.
  ....................: Stop-bit  = Mark  = -3V to -15V on RS-232 or logic 1
on a UART. 
  Parity..............: Simple error detection. Parity can be even, odd,
mark (1) or space (0).
  Modem...............: Modulator/Demodulator
  Boolean Values......: A data type that is True or False, 1 or 0, mark or
space by George Bool in 1847.
  Boolean Logic.......: A Boolean logic/algebra. Made up of and, or, not,
(&) xor logic gates. Ex: out = not (a) and b
  binary..............: Base 2 numbers. Ex: 1010.
  Op-amp..............: Mathematical operational amplifier
  Analog and Digital..: Analog works like a slide rule and digital works
like a soroban or abacus.
  Digital Logic.......: Simple, temperature tolerant, power supply noise
tolerant, uses logic gates and, or, not,
  ....................: exor, ...
  Analog Logic........: Complex, not temperature tolerant, not power supply
noise tolerant, uses operational
  ....................: amplifiers. Non-inverting amps (multiply by gain),
inverting amps (multiply by -gain),
  ....................: summing circuit, voltage divider, Differential
Amplifier (add and subtract) , Integrator,
  ....................: differentiator, ...
  FD..................: Floppy Drive
  HD..................: Hard Drive, High Density, or High-Definition Video.
  SD-Card.............: Secure Digital Card
  SSD.................: Solid-State Drive
  HW..................: Hardware
  FW..................: Firmware. Ex: Code stored in ROM.
  SW................... Software.  Ex: Code stored on a punch card, punch
tape, tape drive, FD, HD, SD-Card, SSD,
  ....................: EEPROM, ...
  CS..................: Chip Select used to enable or disable a silicon chip
/ integrated circuit.
  Tri-state Logic.....: Three-state logic. Ex: high, low, and open circuit
(high-impedance). Like when
  ....................: CS=chip-not-selected.
  1k of data..........: 1k = 1024 bits/bytes of data. 1kb = bits and 1kB =
Bytes.
  1M of data..........: 1M = 1,048,576 or 1024 * 1024 bits/bytes of data.
1Mb = bits and 1MB = Bytes.
  Powers of 2.........: Ex: 1, 2 4, 8, 16, 32, 64, 128, 256, 512, 1k, 2k,
4k, ...
  Powers of 256.......: 256; 65,536; 16,777,216; 4,294,967,296. Or 256, 64k,
16M, 4G, 1T, 256T, 64P, 16E
  Powers of 1024......: 1k (kilo), 1M (mega), 1G (giga), 1T (tera), 1P
(peta), 1E (exa), 1Z (zetta), 1Y (yotta), ...
  TV..................: Television, or tera volt, depending on the context.
  uP..................: Microprocessor
  ALU.................: Arithmetic Logic Unit
  CPU.................: Central Processing Unit
  16-bit address......: Good for 64k bytes/words of memory
  20-bit address......: Good for  1M bytes/words of memory
  24-bit addrsss......: Good for 16M bytes/words of mwmory
  32-bit address......: Good for  4G bytes/words of momory
  64-bit address:.....: Good for 16E bytes/words of memory
  Bus.................: A divce or system for moving data arround.
  Bit.................: Binary Digit that is one or zero
  Nibble..............:  4-bits with            16  (16) combinations from 0
to            15 (    -8 to     7)
  Byte................:  8-bits with           256 (256) combinations from 0
to           255 (  -128 to   127)
  16-bit Word.........: 16-bits with        65,536 (64k) combinations from 0
to        65,535 (-32768 to 32767)
  32-bit word.........: 32-bits with 4,294,967,296  (4G) combinations from 0
to 4,294,967,295
  Volatile Memory.....: Memory is lost when the computer power is lost.
  Non-Volatile Memory.: Memory is not lost when the computer power is lost.
  Sequential Access...: Data must be read in sequential order, like when
loading data from a tape drive.
  Random Access.......: Data can be read in any order. Ex: read byte 7 and
then byte 1, and so on.
  Core Memory.........: Random Access Memory that is non-volatile, and
requires a refresh after each read of a given
  ....................: location.
  RAM.................: Random Access Memory that is readable, writable, and
volatile
  SRAM................: Static RAM does not need to be refreshed (and can be
made non-volatile if you use a battery).
  DRAM................: Dynamic RAM must be refreshed, but is lower cost
than SRAM.
  FRAM................: Ferroelectric RAM that is non-volatile without the
need for a battery, and does not wear out
  ....................: due to use.
  OTP.................: One-time programmable. Some ROMs are one-time
programmable. Some are burned, like a fuse burns
  ....................: out. Some are a EPROM without the quartz window and
ceramic package for cost reduction.
  ....................: Typically you can make a one a zero but you can not
make a zero a one.
  ROM.................: Read Only Memory: Random Access Read Only Memory
that is non-volatile without the need of a
  ....................: battery.
  Mask ROM............: The ROM memory is set by the way it is manufactured
at the factory. The memory cannot be
  ....................: changed.
  PROM................: Progammable ROM or OTP ROM. Perhpas an EPROM without
the UV window, or a burned ROM with
  ....................: so-called fuses.
  EPROM...............: Erasable Progammable ROM (oxymoron). Erasable with
ultraviolet (UV) light with limited number
  ....................: of erase/write cycles.
  EEPROM..............: Electrically Erasable Progammable ROM with limited
number of erase/write cycles.
  SEEPROM.............: Serial Electrically Erasable Progammable ROM with
limited number of writes. Random and
  ....................: sequential access.
  Stack...............: An area of memory that works like a stack of plates,
where the Last On (is the)
  ....................: First Out (LIFO)
  Call Stack..........: This area of memory holds the temp variable,
parameter and the return address of the subroutine
  ....................: and interrupts.
  User Stack..........: This memory is useful for dynamic memory allocation
arrays and such.
  Register............: High-speed memory inside the microprocessor used to
store intermediate results. This includes
  ....................: the accumulator, shift register, index register,
stack/user pointer, program counter, condition
  ....................: codes register.
  Pseudo-register.....: Some microprocessors can use memory on the
memory/data bus almost like a register.
  LSB.................: Least Significant Bit/Byte
  MSB.................: Most Significat Bit/Byte
  Big Endian..........: 16-bit values are stored MSB first in an 8-bit
memory
  Little Endian.......: 16-bit values are stored LSB first in an 8-bit
memory
  CISC ...............: Complex Instruction Set Computer
  RISC................: Reduced Instruction Set Computer (microcode). Simple
HW but uses more code space to store a
  ....................: program.

Key (Memory Architecture):

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  Memory Architecture.: Data is mostly in RAM, but you can have a constant
or constant lookup table in ROM.
  ....................: Firmware code is in ROM, and self-modifing code and
software/application code must be in RAM.
  Von Neumann Arch....: Memory Architecture where data, code, and
self-modifying code are on the same memory bus.
  Harvard Arch........: Memory Architecture where data is on one bus, code
is on another bus and self-modifying code is
  ....................: not available. Some microcontrollers with few
exceptions put the all the code in the EEPROM on
  ....................: the code bus, and all the data in RAM on the data
bus.
  Modified Harvard Arc: Like Harvard Architecture but one can execute code
in the data space with a bridge or
  ....................: something.

Opposites:

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  CISC and RISC
  Big Endian and Little Endian.
  LSB and MSB.
  Volatile Memory and Non-Volatile Memory.
  Sequential Access and Random Access.
  Von Neumann Architecture and Harvard Architecture

-John Mark Mobley