Rochester Electronics, LLC 2908PC

AMD's Am2908 architecture places four D-type registers ahead of open-collector bus drivers, four differential receivers behind a shared bus, receiver output latches and an odd four-bit parity checker/generator in one device. The Am2908 receiver threshold was designed for DEC Q/LSI-11 bus compatibility and differs from the Am2907. Treat these as controlled AMD family comparisons until Rochester supplies the exact lot documentation.

The AMD Am2907/Am2908 product catalog describes 20-pin DIP devices. Rochester's exact 2908PC lot is not mechanically documented in the local catalog, whose package field is blank. A 20-DIP entry exists in the local register, but the actual body width, pin-one mark, lead finish and original manufacturer drawing must be matched to supplied stock. The local JPG is missing.

Layout checks

• Inspect the lot mark and count physical leads.
• Match body width, row spacing and pin-one orientation.
• Verify finish and solderability of legacy inventory.

The missing JPG and incomplete lot-specific package evidence block publication.

In AMD's Am2907/Am2908 family diagram, A[3:0] are registered data inputs, BUS[3:0] are shared driver/receiver nodes, DRCP clocks the driver, BE controls bus drive, RLE latches receiver data and OE controls its three-state output. A parity signal reflects the odd four-bit parity function. These names are for function identification only; obtain the exact 2908PC 20-pin top view before wiring physical pins.

Do not assume the supplied Rochester marking is pin-compatible without the controlled drawing.

Family characteristics and maximum ratings require lot-specific confirmation before use.

No internal replacement is qualified or linked. The Am2907's different receiver threshold can affect noise margin and DEC Q/LSI-11 bus behavior. Compare full pinout, driver sink capability, termination, parity, latch timing, supply, temperature and package dimensions before changing any legacy design.

The catalog names Rochester Electronics as supplier. AMD's original Am2907/Am2908 documentation is the primary family-level technical source, while distributor indexing links 2908PC to that family. The exact original maker and controlled revision of this unprefixed lot are not established by the available listing; request Rochester traceability and a lot-specific data sheet.

Verify markings, original-maker traceability, lot and date codes, moisture/storage history and lead condition. Current marketplace stock and price may not equal this catalog's available lot or quantity breaks. Obtain a dated authorized quote; inventory and pricing remain separate database fields.

Maintain manual review and noindex. Confirm the exact Rochester lot and pinout against manufacturer-controlled documents, verify the 20-DIP package and JPG, reconcile dated stock and tiers, and check the rendered page. No substitution or release is approved.