The colors 0..7 appear in high intensity and the colors 8..15 blink using
low / high intensity. Blinking is not present in Bochs yet. For now, the 3rd
bit of the attribute will be inverted.
- attribute controller mode control register: only a change of the internal
palette size bit should force a redraw
- skip screen update if video is disabled
plane enable and color select
- a screen update is necessary after updating the charmap
- lots of missing parentheses added (found after disabling VGA_TRACE_FEATURE)
- BX_DEBUG and BX_INFO messages improved
- update function: the 'for' loop now initializes and increments the variables
xti and yti
- VBE: banked writes are now ignored in LFB mode, LFB writes are ignored in
banked mode (based on SF patch #742782)
- calculation of the VBE virtual height for >8bpp fixed
- visible screen size must be recalculated after changing the virtual width
- modify standard VGA register when enabling a VBE mode (some test applications
expect this behaviour)
- BX_INFO messages in the VBE code fixed
- don't clear the VBE memory if the new flag VBE_DISPI_NOCLEARMEM is set
- vbe_bpp_multiplier for the 4bpp mode set to 1 (usually unused, but this value is save)
(using 72 Hz vertical frequency). The vertial retrace phase is often used for
vga register or memory manipulations to reduce screen flickering.
- update(): check variable vga_mem_updated before everything else
(without localized variables)
- start address support for CGA modes added
- start address support for mode 13h completed
- clearing the text snapshot is not necessary after a start address change
(set needs_update to 1 in graphics mode only)
and implemented in SDL
* sequencer controller register 0x01 bit 0 controls the width of the characters.
This value is used to calculate the screen width.
* attribute controller register 0x10 bit 2 controls the appearance of graphics
characters (ASCII 0xC0 - 0cDF). A change of this value forces a charmap update
to rebuild the font bitmaps.
* the SDL display library uses the new feature described above
* the other display libraries recalculate the screen width, since they are using
a fixed font width of 8 for now.
- VGA: attribute controller register 0x10 bit 2 (enable_line_graphics) does not
switch the palatte in CGA mode
ATTENTION: the Elpin VGA BIOS uses a delay of 280 vertical retraces after
displaying the copyright text
- changes to the horizontal or vertical pel panning registers force a redraw of
the screen
- screen update problems in text mode fixed
- sort order of the CRT register write cases changed
- fixed calculation of the byte offset for standard VGA modes if line compare
is active
- force a resize of the screen after a change of the display mode (text/graphics)
- mem_write(): skip the rotation of the cpu byte if 'data_rotate' is 0
If set, the screen size will be horizontally doubled in CGA and standard
VGA modes.
- doublescan feature for CGA mode 320x200x4 added
- removed trailing spaces in VBE update code
the address offset between two lines on the screen in all VGA modes.
It depends on the CRTC offset register value and the address mode (byte, word,
dword)
- moved screen update code to the end of the write handler. If a register change
should force a redraw of the screen, the variable 'needs_update' must be set
to 1.
- changes to the attribute controller palette index register now force a redraw
of the screen
- modeX: calculation of the tile numbers fixed
* check memory mapping before everything else
* read mode 1 optimized using a part of patch.vga-mode2-speed-dohzono
- function mem_write(): check memory mapping before everything else
- writes to the CRT registers are handled only if the new value differs
- a CRT start address change forces a redraw of the screen
with 100 rows and a char height of 4
- raster operations AND, OR and XOR in write mode 2 implemented (part of patch #707931)
- use the vga_tile_updated array in modeX like other modes do
- small optimizations in the graphics update code
double width)
- cleanup in modeX emulation similar to mode 13h
- consider start address in function mem_write for VGA modes
- register 0x03c8 is readable, too
- clear tile array when switching to graphics mode, clear text snapshot when
switching to text mode, do the same when changing the palette or disable video
- simplified the function determine_screen_dimensions()
- fixed the code for the CGA mode 640x200x2 in update() and mem_write()
- it works only on x86 with gcc2.95+
- uses the GCC function atribute "regparm(n)" to declare that certain
functions use the register calling convention
- performance improvement is about 6%
palette - it's an index to the attribute controller palette index.
The new function get_actl_palette_idx() now returns the real DAC index.
The guis sdl, wx and x11 are using the new function. TODO: Fix this bug in
all other guis.
* missing VBE support added, use xmax / ymax variables instead of the
values 640 / 480
* use the constant Y_TILESIZE when checking the y position
* variable vga_mem_updated was always set twice
For years we have been writing beyond the end of this array in the VGA code:
bx_bool vga_tile_updated[BX_NUM_X_TILES][BX_NUM_Y_TILES];
and doing who-know-how-much damage to other memory structures in the process.
I changed every reference to vga_tile_updated[][] into calls to two macros
GET_TILE_UPDATED and SET_TILE_UPDATED, and defined the macros to check
the bounds of the array before referencing it. At first I used an
assert, then a panic, then an error, and now I'm not printing any message
at all because there were thousands and thousands of messages during
a boot of win95 when it's updating the win95 logo screen.
- I couldn't resist cleaning up a few confusing-looking things like
"if (condition) { // }". There are no functional changes except for
bounds checking on the vga_tile_updated array.
"bx_bool" which is always defined as Bit32u on all platforms. In Carbon
specific code, Boolean is still used because the Carbon header files
define it to unsigned char.
- this fixes bug [ 623152 ] MacOSX: Triple Exception Booting win95.
The bug was that some code in Bochs depends on Boolean to be a
32 bit value. (This should be fixed, but I don't know all the places
where it needs to be fixed yet.) Because Carbon defined Boolean as
an unsigned char, Bochs just followed along and used the unsigned char
definition to avoid compile problems. This exposed the dependency
on 32 bit Boolean on MacOS X only and led to major simulation problems,
that could only be reproduced and debugged on that platform.
- On the mailing list we debated whether to make all Booleans into "bool" or
our own type. I chose bx_bool for several reasons.
1. Unlike C++'s bool, we can guarantee that bx_bool is the same size on all
platforms, which makes it much less likely to have more platform-specific
simulation differences in the future. (I spent hours on a borrowed
MacOSX machine chasing bug 618388 before discovering that different sized
Booleans were the problem, and I don't want to repeat that.)
2. We still have at least one dependency on 32 bit Booleans which must be
fixed some time, but I don't want to risk introducing new bugs into the
simulation just before the 2.0 release.
Modified Files:
bochs.h config.h.in gdbstub.cc logio.cc main.cc pc_system.cc
pc_system.h plugin.cc plugin.h bios/rombios.c cpu/apic.cc
cpu/arith16.cc cpu/arith32.cc cpu/arith64.cc cpu/arith8.cc
cpu/cpu.cc cpu/cpu.h cpu/ctrl_xfer16.cc cpu/ctrl_xfer32.cc
cpu/ctrl_xfer64.cc cpu/data_xfer16.cc cpu/data_xfer32.cc
cpu/data_xfer64.cc cpu/debugstuff.cc cpu/exception.cc
cpu/fetchdecode.cc cpu/flag_ctrl_pro.cc cpu/init.cc
cpu/io_pro.cc cpu/lazy_flags.cc cpu/lazy_flags.h cpu/mult16.cc
cpu/mult32.cc cpu/mult64.cc cpu/mult8.cc cpu/paging.cc
cpu/proc_ctrl.cc cpu/segment_ctrl_pro.cc cpu/stack_pro.cc
cpu/tasking.cc debug/dbg_main.cc debug/debug.h debug/sim2.cc
disasm/dis_decode.cc disasm/disasm.h doc/docbook/Makefile
docs-html/cosimulation.html fpu/wmFPUemu_glue.cc
gui/amigaos.cc gui/beos.cc gui/carbon.cc gui/gui.cc gui/gui.h
gui/keymap.cc gui/keymap.h gui/macintosh.cc gui/nogui.cc
gui/rfb.cc gui/sdl.cc gui/siminterface.cc gui/siminterface.h
gui/term.cc gui/win32.cc gui/wx.cc gui/wxmain.cc gui/wxmain.h
gui/x.cc instrument/example0/instrument.cc
instrument/example0/instrument.h
instrument/example1/instrument.cc
instrument/example1/instrument.h
instrument/stubs/instrument.cc instrument/stubs/instrument.h
iodev/cdrom.cc iodev/cdrom.h iodev/cdrom_osx.cc iodev/cmos.cc
iodev/devices.cc iodev/dma.cc iodev/dma.h iodev/eth_arpback.cc
iodev/eth_packetmaker.cc iodev/eth_packetmaker.h
iodev/floppy.cc iodev/floppy.h iodev/guest2host.h
iodev/harddrv.cc iodev/harddrv.h iodev/ioapic.cc
iodev/ioapic.h iodev/iodebug.cc iodev/iodev.h
iodev/keyboard.cc iodev/keyboard.h iodev/ne2k.h
iodev/parallel.h iodev/pci.cc iodev/pci.h iodev/pic.h
iodev/pit.cc iodev/pit.h iodev/pit_wrap.cc iodev/pit_wrap.h
iodev/sb16.cc iodev/sb16.h iodev/serial.cc iodev/serial.h
iodev/vga.cc iodev/vga.h memory/memory.h memory/misc_mem.cc
- default value of the sequencer reset bits is 1 (no reset)
- sequencer reset flag 1 resets the charmap select register when cleared
- skip the screen update when the sequencer is in reset mode (h/v sync and
video ram refresh are disabled in that case)
- don't clear the memory update flag before the update is done
- skip the text screen update when the character height is set to 1 (MSL = 0)
- sequencer debug messages updated
if init() is called a second time. This allows me to restart a
simulation (wxwindows interface only) without restarting the whole
application.
- modified: iodev/*.cc
requesting source can be registered as well. Otherwise, there
is no way to know which source modules are requesting
suspect frequencies which are too high.
set_text_charbyte()
- vga: store the address of the active charmap in the new variable
charmap_address
- vga: text mode hack removed. The write modes, operations and masks must be
used in text mode too.
- sdl: clear_screen() is not necessary when the charmap has changed
- win32: update only the changed font bitmaps before drawing the text
vga_charmap
- the SDL gui uses the charmap data for the vga text display
* TODO: implement this feature for other guis
- removed unused variables in sdl.cc and gui.cc
- fixed a warning in vga.cc
