What 74ls series logic was around in '83

matsondawson · Post by **matsondawson** » Thu Jun 09, 2016 5:53 pm

I'm looking at building a cart using the following types of ic:
4k x 8 SRAM
74283 - 4-bit Binary Full Adder
74574 - Octal D-Type Edge-Triggered Flip-Flop with Three-State Output

Were this around in 1983? And if so were they expensive?
I'm trying to make something that would look like it came from that era, and would have been affordable.

eslapion · Post by **eslapion** » Thu Jun 09, 2016 7:02 pm

TI's TTL Data Book Vol. 2 was published in 1985.

It indicates the 74LS283 was available back then. The 574 was not.

Even today, the 574 only exist in CMOS (HC, HCT) and advanced low power Schottky (ALS). The equivalent function IC in TTL-LS series is the 74LS374 which was also available in the early 80s and seems pin compatible with the 574.

The LS283 and LS374 can be purchased new from Digikey or Mouser. I can get vintage NOS from Abra Electronics.

Concerning the SRAM chips, I have never heard of 4k x 8. Standard JEDEC capacities are (AFAIK) 2k x 8, 8k x 8 and 32k x 8.

Added edit:
I got my Ds and Qs mixed up! the '574 and '374 do the same thing but aren't pin compatible at all!

MCes · Post by **MCes** » Fri Jun 10, 2016 1:55 am

'574 and '374 have same function but they are NOT pin compatible

eslapion · Post by **eslapion** » Fri Jun 10, 2016 7:37 am

MCes wrote:'574 and '374 have same function but they are NOT pin compatible

Correct.

The '574 has all input on one side and all outputs on the other side while the '374 has inputs and outputs one after the other.

Denial

What 74ls series logic was around in '83

What 74ls series logic was around in '83

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