Chip Identification

The *74* chips are TTL or TTL-ish logic.

The letter prefix indicates the manufacturer - SN is Texas Instruments. The letter suffix indicates the package - the package codes vary between makes.

Any letters in the middle (like "LS") indicate some variations in the internal circuits.

In general, if all the numbers are the same, the parts have the same logic function.

No middle letters = original fairly power-hungry version. Some parts in this series are still available, I think.

L = low power, slow (and obsolete)

LS = Low Power Schottky. Low power, but similar speed to the original.

ALS = Advanced LS

C = C in the middle letters indicates CMOS - very low power. (and just "C" is fairly slow)

HC, AC = faster CMOS parts

HCT, ACT = CMOS parts with the inputs modified to work reliably with bipolar TTL.

To find data on these parts, check Texas Instruments, Fairchild or On Semi's websites, or do a google for +datasheet.

Those are 74 series TTL logic (except for 2114 which is a 1024 x 4bit static RAM). LS indicates Low power Schottky. The prefixes indicate manufacturer. The suffixes indicate package.

Try searching for the chip numbers on Google. You'll find datasheets. Try searching with .pdf on the end of the chip number.

I recall SN as the Texas Instruments prefix Rich...

Motorolla had their 'Batwing' M

Then there's the suffix: N for plastic (really epoxy) J for cerdip (both halves were ceramic surrounding the lead frame) P for ceramic (hermetically sealed types)

One could really wear off the finger tip skin by handling too many J parts!

The SN is a TI device. The 74 stands for commercial temperature range (for this series) and the LS is Low power - Schottky

This page provides part number prefix to manufacturer, the SN:

This page defines the 'LS' protion

This page defines temp range

Hope this helps.

or

Do you recall TI's multivoltage (probably PMOS) UV EPROM, the TMS 2716? TMS stood for Too Many Supplies rather than Texas (Instruments) Memory Systems.