First check and see if the monitor accepts plain old composite sync from the horizontal sync pin, some do even though their data sheet says otherwise.
http://www.epanorama.net/documents/vga2rgb/vgamonitor.html
See "How can I build a circuit which converts composite sync signal to HSYNC and VSYNC ?"
The LM1881 circuit is easy to build, just two caps and a resistor. To get true HSYNC from it, you need to add some additional parts as shown on that page. As before, check and see if the monitor will take a composite signal for HSYNC in addition to the generated VSYNC.
Another thing you can do is cheat and use a Mac2VGA adapter, many of them have sync separators built in (my Belkin does) since many Macs output composite sync and many VGA monitors only take H+V Sync.
http://www.epanorama.net/documents/vga2rgb/vgamonitor.html
See "How can I build a circuit which converts composite sync signal to HSYNC and VSYNC ?"
The LM1881 circuit is easy to build, just two caps and a resistor. To get true HSYNC from it, you need to add some additional parts as shown on that page. As before, check and see if the monitor will take a composite signal for HSYNC in addition to the generated VSYNC.
Another thing you can do is cheat and use a Mac2VGA adapter, many of them have sync separators built in (my Belkin does) since many Macs output composite sync and many VGA monitors only take H+V Sync.