Because SPI is clocked, and the slave-select line delimits ... If you’re using an SD-MMC card, or if all else fails, or if you’re just somehow superstitious, you can try adding pull-up ...
The next-generation of line-cards will see a rationalisation from the current variety of interfaces in use, such as SPI-4.1, CSIX L1 and OEMs' own proprietary solutions towards SPI-4.2. The ...
As for 1.8V rail, she ended up tapping the 1.8V power pin of the SPI chip the motherboard itself ... Use your Pico as a POST card!