Maxtor XT-2190 controller board chip research (circa 1985-1993)

Hi. I'm new here, and I restore vintage computers as a hobby.

I'm trying to learn about an integrated circuit chip on the controller board of a very old hard drive.

It's the largest chip on the controller board for all of my Maxtor XT-2190 MFM hard drives.

68 pins (17 X 4)



Searching Google (at least the way I'm going about it) isn't yielding any datasheets for this chip I'm hoping to research.

Identifying Numbers by Frequency of occurrence:

4.....100213
4.....1047013 REV A
2.....SP0017
1.....100299
1.....7A1UNE4311
1.....J1128
1.....N 417
1.....RCA N 726
1.....RCA N 819
1.....RCA N 821
1.....RCA Z 930
1.....TA20514-625

I'm home that some members here would likely look at this a little differently than I do, and help me search differently.

And please let me know if there is a more appropriate topic section or forum for me to ask this question.

Thank so much,
-AJ
**broken link removed**

The numbers are in-house codes, although the devices may have generic part numbers the ones on them will not lead to any information.
I suspect, although I could be wrong, that they are some kind of memory device. The clue may be that very few of the Z86 family processors have internal program memory, they need to get their instructions from an external memory and there is no other memory on the board. The different part numbers may be due to different releases of software stored inside them. If I'm right, even if you found out the generic part number and could source them, without the program code to put in them they would be useless.

Brian.