5380 vs. 53C80 vs. 53C80S ?

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Tinkerer
Oct 25, 2021
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This is related to my earlier thread, https://tinkerdifferent.com/threads/53c80-experiment.272/

Logic, in their datasheet claims that their 53C80 has better performance:

It is pin and functionally compatible with the NMOS NCR5380, while offering up to a 2.5x performance improvement, 10x power reduction, and lower cost. Replacement of the NMOS 5380 by the LOGIC Devices L5380/53C80 will result in an immediate transfer rate improvement due to REQ/ACK and DRQ/DACK handshake response times up to 5times faster than previous devices.

So I actually looked at the pinouts in the Logic datasheet (datasheet attached in above linked thread). And the pinouts for Logic's 5380 and their 53C80 are completely different.

So, first question, are the NCR 5380 and 53C80 pinouts different? Did they change the pinout when they went from NMOS to CMOS?

2nd question. Anyone ever seen a pinout for a QFP version of the 53C80? It is also 44 pins, so may be the same as the PLCC, but assuming can be dangerous. LSI Logic made a 53C80S in a QFP package and I can't find a datasheet anywhere.

My experience hunting for a 53CF96 datasheet from them (LSI) is that they didn't go to PDFs until later than everyone else. So one almost must find a print version. Happily when I was hunting the 53CF96 it was over 20 years ago, and I was able to get them to mail me a copy, but the part wasn't very obsolete yet, then.

Anyway, looking for an LSI 53C80S datasheet -- or just the pinout to their QFP version.
 

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Tinkerer
Oct 25, 2021
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And in the fine tradition of only finding the answer after one has bothered other folks with the question, I found this datasheet at a vendor who has the SYMBIOS 53C80 available. NCR semi was spun off into SYMBIOS, which was bought by LSI Logic.... None of which are the same as teh company Logic.

Anyway, looks like the 5380 PLCC is different from the 53C80 PLCC is different from the 53C80 QFP. The latter two are barely different. They just moved the NC pins around a bit darn them.

So do all the Apple boards stick with the 53C80 or do some of them use the 5380? (excluding the later boards that move on to other chips).
 

Attachments

  • SYM53C80.pdf
    2.3 MB · Views: 144

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Tinkerer
Oct 25, 2021
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And as it turns out, I didn't find the answer.

The QFP 53C80 in the datasheet attached to the previous post has 48 pins.

The QFP 53C80s I received have 44 pins. So I still don't know whether they match the PLCC pinout. Sigh.
 

InsufficientPostage

New Tinkerer
Sep 3, 2024
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Did you ever experiment with this or get an answer? I have an SE/30 with a potentially bad SCSI controller, and grabbed a couple 53C80E's and a 53C80S to try to replace it, but I'm worried that the revisions will somehow not work.
 

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Tinkerer
Oct 25, 2021
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No, I never did the experiment. I'm great at posing questions, but less so at making answers. Projects backed up to the year 3000...