I am using an old IBM 5081 12 monitor, a 19" Sony Trinitron monitor with RGB inputs and originally equipped with Sync-on-Green. Using a small circuit I have converted it to the 5-wire system (separate HSync and VSync inputs in addition to the RGB signals) used by VGA display adapters. When your VGA card can generate a dotclock of about 110 MHz, the monitor can generate a 1280x1024 display at 64 KHz horizontal, 60 Hz vertical.
A short description of the circuit: ibm5081-12-vga.txt