Micronics motherboard has that MIC491 chip located in perfect VLB spot, right on CPU address/data busses.

douglar wrote on Yesterday, 17:58:

The traces for the IDE go to the back of the board, then come up for the yellow chips

resistor networks.

douglar wrote on Yesterday, 17:58:

then go to the back of the board to come up under the TI PAL chips.

data from 245 goes further all the way to around U50, also perfect spot for landing on CPU Data bus where ram data connects thru another bunch of resistor networks.
3 PALs is too much for stupid PIO controller, I would asses it as probably local bus IDE controller
one thing - arent VLB controllers meant to take 32bit writes and convert on the fly? connecting 16bit IDE data path directly to RAM data bus suggest there is no byte swapping/FIFO magic happening here.