Scrolling doesn't work in Bochs

[leledumbo]

I'd like to ask this a long time ago, but I always forgot since I prefer using QEMU. My screen scrolling code works fine under QEMU but not under Bochs. Here's my bxrc file:

Code: Select all

###############################################################
# bochsrc.bxrc file for FPOS cdrom image.
###############################################################

megs: 128
romimage: file=C:\Bochs\BIOS-bochs-latest
vgaromimage: file=C:\Bochs\VGABIOS-lgpl-latest
ata0-master: type=cdrom, path="fpos.iso"
boot: cdrom
log: fpos.log
mouse: enabled=0
clock: sync=realtime
cpu: ips=500000

Do I miss some options or something? The code is taken from Bran's Kernel Development Tutorial.

[jzgriffin]

Could we see your scrolling code?

[Combuster]

Bochs' VGA emulation is minimalistic and it wouldn't amaze me if the register was unimplemented.

[stlw]

cpu: ips=500000

BTW, you have very nice IPS settings. This might be correct one only if you emulating 8 wide SMP system or running emulator on some kind of old good 486 computer.
Normal settings for any modern host should at least 25x of this value, when Core 2 Duo 2667 Mhz has 75x of this value.
BTW, IPS affects everything in the emulation, even might affect your scrolling as well

Stanislav