Rochester Electronics, LLC 74S288AV

The 74S288 family stores a one-time-programmed 8-bit output word at each of 32 addresses. Rochester supplies the 74S288AV for legacy maintenance where electrically and mechanically compatible OTP PROMs are needed. The local catalog has no package designation, and available secondary listings do not constitute a controlled package drawing.

• 256-bit memory organized as 32 words by 8 bits.
• TTL-compatible parallel address and data interface.
• One-time-programmable nonvolatile storage for fixed logic tables.
• Compact memory organization for legacy board repair.
• Rochester cross-reference to 27S19AJC, subject to verification.

The family uses five address inputs to select one of 32 eight-bit words. An enable input controls output availability. As a bipolar fuse PROM, it must be programmed using an approved procedure and programmer; it is not an electrically erasable memory. Verify output polarity, enable behavior and timing from the exact Rochester-controlled data sheet before replacing a board device.

The catalog package field is blank. A Rochester-referenced engineering directory classifies the AV variant as PLCC20, whereas N and AN variants are listed as PDIP16. The exact 74S288AV mechanical drawing and pin map were not obtained. A 20-PLCC is therefore a candidate requiring manufacturer confirmation, not an approved footprint. The local 20-PLCC JPG and package registry are missing.

Assembly checks

• Obtain the Rochester AV package outline and lead numbering.
• Compare socket or PCB footprint with the controlled drawing.
• Verify the programmed pattern and output orientation.

Family-level signals include address inputs, eight parallel data outputs, enable/control, 5 V supply and ground. The candidate PLCC20 pin positions must not be inferred from a PDIP16 family diagram. Verify the exact 74S288AV ball/lead assignment and programming pins using Rochester documentation.

Only family-level memory architecture is established here; exact AV timing, outputs, programming and package require controlled documentation.

The database also contains 74S288AN and 74S288N. These are family comparisons only: distributor package classifications suggest DIP versus candidate PLCC for AV. Even a pin-compatible PROM requires the same programmed data image, output polarity and speed. Rochester's 27S19AJC cross-reference is not a substitute for such validation.

Rochester's product-family description identifies the 74S288 as a 32 x 8, 256-bit TTL PROM. Historical Signetics and Texas Instruments manufacturer-authored family material corroborates the generic 74S288 memory architecture. No current Rochester-controlled 74S288AV electrical, programming and mechanical data sheet was retrieved; obtain it before technical release.

• Legacy board identification and small fixed lookup tables.
• Industrial or computer equipment repair using programmed PROMs.
• Validated replacement of obsolete bipolar memory.

Inspect device markings, lot and date code, packaging and especially the programmed image. The local catalog lists 11,197 units at USD 9.64, minimum quantity 11, no tiers. Current exact-code external listings diverge: an indexed Rochester offer reports 13,245 units at USD 25.13 for one and USD 23.62 for 100; a separate seller reports 10,000 at USD 12.3065 for one and USD 11.5681 for ten. These listings are unverified seller claims, and the catalog stock/price conflict requires procurement review. Do not change catalog values without authorization.

Obtain the manufacturer-controlled AV data sheet, package outline, programming algorithm and known-good memory image. Missing package JPG/registry and unresolved distributor stock/pricing prohibit publication. Keep this record in manual review with noindex until all checks pass.