bandwidth on the neck board was an issue if I recall. But the circuit diagram of the Xceed neck board is available, so you could whip up a quick replica.
Anyways... for shits and giggles, try 512x384, which is the mac 12" RGB Resolution. As for increasing the voltage, Try a boost converter coil in the yoke circuit? Sure you have to calculate it out but with the correct value, the discharge on the coil should charge the voltage to drive the yoke. In normal circuitry, the flyback acts as this. But in your case you dont have that. So make one
If this means anything, I recall working on monitors way back in the day that had split-horiz systems. the horizontal yoke output, and flyback output were separate. And in all cases that I can recall, the horizontal yoke stage always had a SMPS-Sized transformer in there. either as a transformer, or as a coil. I cannot recall. But it was there. Projection TV sets come to mind. Mitsubishi, and Hitachi.
The issue your having with width could be the reason why they use horizontal output transformers. Maybe to Impedance match the yoke against the circuit, or as a charge-pump boost type thing.
Anyways... for shits and giggles, try 512x384, which is the mac 12" RGB Resolution. As for increasing the voltage, Try a boost converter coil in the yoke circuit? Sure you have to calculate it out but with the correct value, the discharge on the coil should charge the voltage to drive the yoke. In normal circuitry, the flyback acts as this. But in your case you dont have that. So make one
If this means anything, I recall working on monitors way back in the day that had split-horiz systems. the horizontal yoke output, and flyback output were separate. And in all cases that I can recall, the horizontal yoke stage always had a SMPS-Sized transformer in there. either as a transformer, or as a coil. I cannot recall. But it was there. Projection TV sets come to mind. Mitsubishi, and Hitachi.
The issue your having with width could be the reason why they use horizontal output transformers. Maybe to Impedance match the yoke against the circuit, or as a charge-pump boost type thing.