platform

Glossary

• Card: A module that plugs into a Slot. A Card is either a Mainboard or an Expansion Card.
• Slot: A receptacle for a Card. A Slot is either the Mainboard Slot or an Expansion Slot.
• Mainboard Slot: The single Slot in a system intended for the Mainboard. There is exactly one Mainboard Slot per system.
• Expansion Slot: A Slot intended for an Expansion Card. The Ashet Home Computer has seven Expansion Slots.
• Backplane: The interconnect containing the Mainboard Slot and Expansion Slots and connecting their signals.
• Southbridge: The Propeller 2 on the Backplane dispatching data between the Mainboard and Expansion Cards. Provides the main electrical expansion interface.
• Mainboard: A Card containing the CPU and RAM of the system and running the OS.
• Expansion Card: A Card that provides additional, user-selectable features to the computer.
• Not-so-mainboard: A Mainboard operating in an Expansion Slot using the Platform's Not-so-mainboard mode. Read the name as "(not-so-main) board", not as "not-so (mainboard)".
• Low-Level-Driver: Firmware running on the Propeller 2 Cog associated with an Expansion Slot. It translates packet/datagram traffic into the card-specific electrical protocol and does not directly provide OS functionality.
• Expansion Card Driver: Driver code running on the Mainboard that exposes an Expansion Card's functionality to the Mainboard operating system. It communicates with the card through the Southbridge/Low-Level-Driver path and controls Mainboard-side interfaces such as HSTX.
• Cog: One of the eight CPUs inside the Propeller 2. Use Cog, not Core, for Propeller 2 CPUs.
• Southbridge Management Cog: The Propeller 2 Cog responsible for managing Low-Level-Drivers and communication with them. It runs in Cog 7 after bootstrap.

Terminology

Use Card when a statement applies to both Mainboards and Expansion Cards.

Use Slot when a statement applies to both the Mainboard Slot and Expansion Slots.

Avoid these terms:

• Expansion Card Slot; use Expansion Slot
• Mainboard Card; use Mainboard
• Expansion as a standalone noun; use Expansion Card, Expansion Slot, or the specific interface name
• Port / port when referring to a Card/Slot receptacle; use Slot
• Expansion Port; use Expansion Slot
• Card Port; use Slot or the specific Slot type
• Mainboard Port; use Mainboard Slot

Project Status

High-level unresolved design work is tracked in Open Topics.md.