Clock

Clock:

AppleWin emulates a No-Slot clock (aka NSC).

This is a chip (a Dallas SmartWatch DS1216) that sits under one of the 28-pin (or 24-pin) ROM chips in the Apple II.
No hardware configuration is required: this chip is always present (unless -no-nsc is used), but won't interfere with system operation when not in use.

It requires a software driver to be installed (for DOS and ProDOS). This driver then emulates the Thunderclock card.

For the Apple //e, here's a summary of NSC/ROM chip locations and which drivers work:

• "CD" ROM socket: $C000-DFFF (internal) ROM space - all drivers work
• "EF" ROM socket: $E000-FFFF ROM space - never seen any drivers use this space
• "CF" ROM socket: $C000-FFFF (internal) ROM space - all drivers work
• Slot ROM socket: $Cs00-CsFF (slot) ROM space - NS.CLOCK.SYSTEM works

Here are the drivers and ROM pages they check:

• ProDOS "SWU.SYSTEM" - internal C3
• ProDOS "NS.CLOCK.SYSTEM" - internal C3 C8 / external C1-C7
• GEOS "NoSlot Clock" - internal C8
• ProDOS-8 v2.5.0 "NoSlotClk.IIe" - internal C3 (currently 65C02 only)

For the Apple II/II+, here's a summary of NSC/ROM chip locations and driver information:

• "F8" ROM socket: $F800-FFFF (internal) ROM space - ProDOS-8 v2.5.0a8 (not currently working)

Here are the drivers and ROM pages they check:

• ProDOS-8 v2.5.0 "NOSLOTCLK.II" - internal F8

NOTE: For ProDOS, the load order of drivers is important:

Some .SYSTEM drivers will not chain-load the next driver.
NS.CLOCK.SYSTEM does, so ensure this is the first one ProDOS finds, whereas ZIP.SYSTEM doesn't so put this at the end of the chain.