! Attempts to read the sector located at @c track and @c sector. @returns a sector if one was found; @c nullptr otherwise. */

Helper to discern current IRQ state

! Sets the current state of the key-on input. */

! Sets the current level of an output line on this serial port. */

@returns The command requested. Valid only if @c has_command() is @c true.

! Schedules @c action to occur in @c delay units of time. */

The destination register index. i.e. 'Rd'.

! Severs from @c this the effect of dividing by @c divisor; @c this will end up with the value of @c this modulo @c divisor . @c this divided by @

@returns The address of the instruction that should be fetched next. So as execution of each instruction begins, this will be +4 from the instruction

! @returns The current attenuation level due to key-level scaling. */

Flag getters.

! For a machine watching only the RWB line, evaluates to @c true if the operation is any sort of write; @c false otherwise. */

@returns The immediate value provided with this instruction, if any. E.g. `ADD AX, 23h` has the operand `23h`.

MARK: - TimedMachine.

The base register index. i.e. 'Rn'.

@returns @c true if all result bytes are exhausted; @c false otherwise.

Enqueus @c post_action to be performed asynchronously at some point in the future. If @c perform_automatically is @c true then the action will be perf

@returns The last observed input.

Enqueues @c value for output.

Sets @tape as the tape player connected to this VIA.

! Terminates a SCSI command, sending the proper sequence of status and message phases. */

! @returns true if any data select line is active; @c false otherwise. */

Posted by @c perform after any operation which affected a segment register.

Provides the next channel to fetch from, or that a write is required, along with a count of complete channel iterations so far completed.

! @returns Current phase; real hardware provides only the low ten bits of this result. */

Sets the interrupt lines, IPL0, IPL1 and IPL2.

! Sets to @c value the 8- or 16-bit portion of the supplied value that is currently being read. Assumes this is a read cycle. */

! Reduces this @c Time to its simplest form; eliminates all common factors from @c length and @c clock_rate. */