That specific board looks like a challenge, closest I can find is same PCB and chipset with a 386SX on it: https://theretroweb.com/motherboards/s/juko-b0007

Unfortunately there's no jumper info on that one either.

However, let's do a step back first: exactly what "1mb sticks" are you talking about? I'm assuming you mean 1MB 30p SIMMs, but beyond that...
- parity or non-parity?
- 2x 4Mb chips or 8x 1Mb chips?
- what speed rating?
- which SIMM slots are you putting them in?

You currently have 1 bank of 16 256kb 80ns chips (i.e. non-parity) for a total of 512kB. A memory bank on a 286 is 16b wide, so you need to place SIMMs in pairs. The pic on TheRetroWeb shows a board with the same memory controller handling four 30p SIMMs with 2 (assumedly 4Mb) chips each, so based on that I'd expect 2-chip and 8-chip non-parity to work as long as it's capable of at least 80ns (lower is better). Whether it can support 4 SIMMs with on-board RAM installed is another matter, so I'd suggest trying with a pair of SIMMs first; try them in the bottom two SIMM slots, if that doesn't work try the top two.

https://theretroweb.com/motherboards/s/juko-b0007

not much on it - you should submit more info!

Thanks guys, I figured it out.

Using these dip switches:

https://i.postimg.cc/6t5hV7RV/IMG-0427.jpg

and populating all four ram banks with 8x1mb no parity modules I got it to work nicely and full 4MB is recognised now.

What four banks? This board only has three (onboard, SIMM1+2 and SIMM3+4)

Looks like MS0 is the onboard RAM and BS0 and 1 are the two SIMM banks.

Given lack of documentation it would be good to see what happens with these settings:
- MS0, BS0 and BS1 all on (does it give 4.5MB, 4MB only or errors?)
- MS0 and BS0 on, BS1 off (2.5MB or errors?)
- MS0 and BS1 on, BS0 off (2.5MB or errors?)

Sorry, wrong terminology. I meant to say four memory slots, two banks.

If MS0 is on ans BS selectors on too, it wont boot.

I have to have ms0 on off, bs0 off and bs1 on and then all four sims are recognises and i get 4mb of ram.

If i turn on ms0 with above setup, only 1mb is shown on boot.

OK, so it can only handle two banks at a time. Shame as there are 286/386SX controllers and motherboards (see Necroware's Vectra 386/33N video from last week) that can combine onboard RAM with two banks of SIMMs.

Still interested to see if it can do MS0, BS0 off, BS1 on with only third and fourth SIMMs populated. I suspect that should give 2.5MB.