5V 4Mbit async SRAM in a 36-SOJ — what you're getting
The CY7C1049B-17VC: It runs on a 5V nominal supply (4.5V to 5.5V range) and uses a parallel interface. The package is a 36-pin SOJ (Small Outline J-lead), surface-mount, with a body width of 10.16 mm (0.400"). J-leads are more robust than gull-wing for manual rework — the leads tuck under the body, so there's less risk of lifting a pad when you hit it with hot air.
No further factory orders are being accepted, and no last-time-buy window remains open. If this part is on your BOM, you are now in the surplus-and-broker channel for any future procurement. There is no official Cypress successor listed for this exact order code. For a legacy board that cannot be redesigned, the practical path is to source from independent distribution. Expect to work with date-code mixes; the 17 ns speed grade and 5V supply are the two parameters that must match to keep the bus timing intact.
Write cycle time is also 17 ns. The 512K x 8 organization means the data bus is 8 bits wide.