Hadn't heard of it but worked up a search anyhow:
This DFI EB3486-TN motherboard manual mentions the TACT84544 (but none of the others): http://www.elhvb.com/mobokive/Archive/Dfi/man … tn/eb3486tn.pdf
... ie. MB 486 DIAMOND FLOWER, REV A, W CPU MODULE EN4DCW-25/33 REV0 https://www.newegg.com/Product/Product.aspx?I … =9SIAB5A6CR9148
Looks like the photo on Newegg has the chipset!
These are probably all worth checking into: https://www.google.com/search?q=80486SX+%22Ch … fe=off&filter=0
Otherwise seems to come up as a chipset in certain model Unisys 486 complete server systems and workstations:
Which don't exactly run Windows AFAIK.
https://groups.google.com/forum/#!search/tact … -place=overview
Unisys 6000 DT/2
Unisys 6000 DT/3
Unisys MPE 56081
Unisys MPE4333E
and others
https://groups.google.com/d/msg/comp.sys.unis … U4/p-mzHLzOWhUJ
https://groups.google.com/d/msg/comp.sys.unis … bA/jiQhammplLEJ
Beware, the DT2/3 like the U6000/100/300 and their associated PC models, were based upon a horrid TI TACT 84500 EISA chipset. The chipset was pretty buggy, and ... well you know the rest. If you are porting an O/S to it, TI did do a developers guide to the TACT 84500 chipset, it may be worth investigating. However, the boards do have many additional configuration registers which override the TI mapped registers.
...
For your search, the MPE56081 was also sold as the U6000/300. The 486 version was sold as the U6000/100. They all used the same […]
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For your search, the MPE56081 was also sold as the U6000/300. The 486 version was sold as the U6000/100. They all used the same basic ECU/SCU programs (.EXE files), but with differing config .CFG files. The .OVL files MAY be the same but I doubt it. I used to configure my U6000/300 (and U6000/500 Model 20 - the dual CPU version of the U6000/300) with a U6000/35 ECU/SCU software set, I just used the new .CFG and .OVL files.
...
Now, word to the wise, these systems were based upon a very buggy EISA chipset from TI, the TACT84500. Also, the system motherboard, the
processor board and evene the memoy board had all kinds of latent bugs in them. The systems have a notorious habit of hanging and crashing. One particular trouble maker is the CPU board to motherboad connectors. Make sure everything is screwed down real tight.
Also seems to have been used in some PA-RISC systems (non-Intel as far as I know) but beats me which, there's a list of models that could have here:
https://www.openpa.net/pa-risc_chipsets_lasi.html
There's some sort of 1 page article about it at Heise, pay 0.99 Euro to read it (IIRC they take Paypal): https://shop.heise.de/katalog/eisa-chipsatz-v … xas-instruments
Various patents mentioned the documentation Texas Instruments published for the chipset, they are as follows:
- Texas Instruments, TACT84500 EISA Chip Set, Designer's Handbook, 1991
- Texas Instruments, TACT84500 EISA Chip Set User's Guide, 1991
- Texas Instruments Corp., TACT84500 EISA Chip Set, Preview Bulletin, 1991
For a time, you could request out-of-print manuals from them (and they'd send it via fax or email) but I believe those days are probably long past. Never hurts to try, though. Otherwise maybe eventually Bitsavers will get their hands on documentation, but it might take another decade or two.
This guy mentioned the chipset in his online resume and perhaps could tell you about the chipset if you ask: https://www.linkedin.com/in/pete-nelsen-0867a55/
What brings up this direction of research, idle curiosity? 😀
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