Description:

Lot of four (4) MMI PAL16R4ACN programmable logic devices in DIP-20 through-hole packages. PAL16R4A family parts are classic PAL/SPLD chips used in vintage and industrial electronics to replace lots of 74xx glue-logic with one programmable device. Markings include “PAL16R4ACN” with date/lot codes like 945ANLN (see photos).

Features & Specifications:

- Manufacturer/marking: MMI (Monolithic Memories / legacy PAL family)

- Part number: PAL16R4ACN

- Device type: PAL / SPLD (Programmable Array Logic)

- Logic function: 16R4 class (registered outputs)

- Macrocells: 4 (registered outputs)

- Output enable: Tri-state capable (bus sharing)

- Interface: Parallel logic + programming via JEDEC file (programmer required)

- Supply: 5V TTL-compatible logic (typical PAL family)

- Package: DIP-20 (through-hole)

- Quantity: 4 pieces (one lot)

Modern uses:

- Repair/restoration of legacy industrial boards, telecom gear, arcade/retro computers

- Replacing failed glue-logic PALs on older PCBs (when you have the original JEDEC)

- Retro-computing projects that need authentic PAL timing/behavior

Compatibility note:

These PALs require a compatible PAL programmer and the correct JEDEC/fuse map. Programming/erase capability depends on the exact technology variant—assume “one-time programmable” unless you know your programmer/device supports erase. Confirm PAL16R4A family/pinout, output polarity (registered), and OE behavior before purchase/installation.

Applications:

- Address/control decode logic

- State machines and timing generation

- Bus buffering / chip-select logic in vintage designs