Macintosh Quadra 840AV upgrades

A 40 MHz 68040 audio-video Macintosh with a DSP, three NuBus slots, built-in video, Ethernet, and SCSI.

Also called: Quadra 840AV

At a glance

Introduced: 1993

Products listed: 2

Exact-model evidence: 2

Family/interface evidence: 0

Upgrade types: 2

Vintage searches: 0

Upgrade directory: Quadra 840AV

Browse everything below, or filter by product type, availability, and compatibility basis. Notes explain whether evidence names an exact target, a broader family, or only the relevant bus or interface for this computer.

Showing 2 products.

StatusProductWhat it doesLinks
AvailableChecked Jul 24, 2026SMC 512 KB VRAM SIMMby Infinity Products
512kb68 pin vramvrammemory expansionvideo memoryoverclocking

512 KB 68-pin Macintosh VRAM module sold in a premium 60 ns design and a limited early four-chip design.

For this system (exact model): The premium 60 ns design explicitly lists the Quadra 840AV.

The premium 60 ns module and the final red clearance modules were listed on 2026-07-24. The purple early-production modules were sold out with no planned rerun. Modules are sold individually; systems with two sockets require two purchases.

Sources
Premium 60 ns moduleEarly four-chip module
AvailableChecked Jul 24, 2026Spicy O'Clockby Infinity Products
68040overclockingclock generatoroscillatorsoldering

Provides finely adjustable clock generation for selected 68040 Macintosh logic boards using an XC88916-family clock driver.

For this system (exact model): The Quadra 840AV is explicitly named. Its stock 40 MHz processor leaves less overclocking margin than slower 68040 systems; cooling and stability testing are essential.

The current product page listed the module without an out-of-stock marker on 2026-07-24. Installation, measurement, cooling, stability testing, and any resulting hardware damage remain the user's responsibility.

Sources
Spicy O'Clock product and compatibility page