[GTALUG] "Atom Pi"

[Stewart C. Russell]

On 2019-09-17 10:20 a.m., D. Hugh Redelmeier via talk wrote:
> 
> - when they are gone, they are gone.  This means that one should not
>    use these in a project that expects system replication over time.
>    [Few of my projects are intended to be replicated.]

A wise person once told me “Don't specify surplus”, and that's served me 
well. I see so many maker projects that are based on a critical 
component that was available as surplus. These are dead projects now.

(example: Active Surplus used to have a good-sized alphanumeric display 
available for 50¢. They came with no datasheet and had a distinctive 
1.27 mm pitch not-quite-flexible ribbon cable. Turns out that this 
display had a very strange clocking requirement that relied on a 
long-superseded driver chip. Getting anything to display on it at all 
was extremely difficult even with a fast microcontroller.)

> Those are useful labels for consumers (which we are).  I thought you
> had some technical issues in mind.

Turns out that you can get much higher rates in benchmarks with certain 
cards and a Raspberry Pi 4, but in day to day mixed use, there's not 
much in it. It seems confusing: 
https://www.jeffgeerling.com/blog/2019/raspberry-pi-microsd-card-performance-comparison-2019

> - the first MMC cards were dead simple to read and write.  I think that
>    a simple parallel port could do it (slowly).  One data pin!

Note that this is still the way you have to do it, unless you want to 
buy a licence from the SD Association.

>    I daydreamed about adding a disk to my Altair using this simple
>    interface.

Josh Bensadon, a local retro computer guru, recently made a whole new 
S100 CPU card with an SD card for storage. It's only as fast as the 2 
MHz 8080A can move data, though:
http://www.s100computers.com/My%20System%20Pages/8080%20CPU%20Board/8080%20CPU%20Board.htm

cheers,
  Stewart