VGA_CRTC_H_DISP
wreg_crt(cirrus, VGA_CRTC_H_DISP, hdispend);
outb_p(VGA_CRTC_H_DISP, vga_video_port_reg);
vga_wcrt(regbase, VGA_CRTC_H_DISP, hdispend);
par->crtc[VGA_CRTC_H_DISP] = (xres >> 3) - 1;
write3X4(par, VGA_CRTC_H_DISP, hdispend & 0xFF);
par->crtc[VGA_CRTC_H_DISP] = xres - 1;