The nearly same card at the vgamuseum shows 4 jumpers, yours has two plus a two hard wired ones near the 14Mhz XTAL. I have one similar but different company and it has 3 jumpers: Irq2/9 enable/disable, Wait state enable/disable and Interlaced/non-interlaced monitor.
The jumpers on those cards are typically for Irq2/9 enable/disable, Wait state enable/disable and BIOS enable/disable or Interlaced/non-interlaced monitor.
Cannot find the exact layout of your card in in TH99 but found a few that were very close.

Horun wrote on 2020-04-22, 00:46:

The nearly same card at the vgamuseum shows 4 jumpers, yours has two plus a two hard wired ones near the 14Mhz XTAL. I have one similar but different company and it has 3 jumpers: Irq2/9 enable/disable, Wait state enable/disable and Interlaced/non-interlaced monitor.
The jumpers on those cards are typically for Irq2/9 enable/disable, Wait state enable/disable and BIOS enable/disable or Interlaced/non-interlaced monitor.
Cannot find the exact layout of your card in in TH99 but found a few that were very close.

Thanks for checking. I will do a little more research and testing and see what I can figure out.

I finally found the jumper settings for this card:

JP1 - IRQ2 Line Status
1-2 - IRQ2 Enable
2-3 - IRQ2 Disable

JP2 - MCS16 Line Status (Jumper not present - Permanently soldered to 1-2)
1-2 - ET4000 VGA Chip generate
2-3 - External decoder

JP3 - Turbo Mode
1-2 - Disable
2-3 - Enable