Powershot SD4500 IS (USA) / IXUS 1000HS (Europe) / IXY 50S (Japan).
CHDK is available in an early BETA version for the Powershot SD4500IS / IXUS1000HS / IXY50S firmware 1.00d, 1.00f, 101a & 1.02b See the links below for source and binary. Also available from the CHDK SVN server in source form.
→ Camera specifications: Canon (English)
- DIGIC IV image processor
- DryOS operating system
- 10.0 megapixel back-illuminated CMOS, 1/2.3 inch (pixel density: 35 MP/cm²)
- Lens: 36-360mm (35mm equiv), 10x optical zoom, F3.4-5.6
- Image stabilization (lens shift type)
- Display: 3.0 inch LCD, 230,000 pixels
- Built-in flash
- Video: 1920x1080 @24 fps HD, 1280x720 @30 fps HD, 640x480 @30 fps, 320x240 @30 fps, Super Slow Motion movies @240 fps
- Video format: H.264 MOV (Motion JPEG + Linear PCM (Stereo))
- Maximum clip length: up to 4 GB or 10 minutes (in full HD & HD mode), up to 4 GB or 1 hour (in L and M mode)
- HDMI mini connector
- Storage: SD, SDHC, SDXC, MMC, MMCplus, HC MMCplus
- Power: Canon Li-ion Battery NB-9L
- Dimensions: 101 x 59 x 22 mm, Weight (with battery): 190g
This section describes special CHDK-related things...
The video key press short switch the chdk alt mode. press long record video
chdk menu make card bootable does not work. Use a Program on your PC to make the Card bootable. Remember the 4 GB Limit of boot Partition. I suggest to use 2 4 gb Partitions so you need switch partitions only when 4gb is full when you want read data.
Switch partitions chdk menu work. After that switch off and on the Camera
This camera use a #define cam_CFAPattern 0x01020001 // Green red blue Green
bayer pattern. So only DNG RAW work. For cr2 need change the converter to support this pattern
- use dancingbits #5 encoding (cajun chicken flavour, like S95) for diskboot.bin  (NEED_ENCODED_DISKBOOT=5)
- use KEYSYS=d4b keys for PS.FI2 encoding
Greeen LED backside 0xC0220130
Red LED backside 0xc0220138
Available firmware dumps
- Firmware version 1.00D (8MB full, dumped with CBasic udumper, )
- Firmware version 1.00F (8MB full dump, )
- Firmware version 1.01A 
- Firmware version 1.02B (8MB full dump,  )
Download location for firmware dumps:
- IXUS 1000HS porting thread: forum link
News & Development History:
As of October 21, 2011, the source for the current release of the SD4500 is available from the chdk SVN servers at http://tools.assembla.com/svn/chdk/
older source and binary are here for 100d Version.
even older source
Some Notes about that version
always developer need that can help to fix problems.here are Problems that get with this port and are solve, maybe help other Porters
http://chdk.setepontos.com/index.php?topic=6037.0 Status 6/2011
Grids work now correct in 4:3 shooting mode
refocus and reexposure during video record work now ok with the Set button
Histogram/Zebra/edge Overlay work on in 4:3 shooting Modes ok.start crash and RAW continues shoot crash finally fix, thanks to Code from philmoz
For 100F best is add this code too, to avoid slowdown or crashes on RAW better
ISO overwrite work, when you set 1 of this allowed values.125,160,200,320, 400, 640, 800, 1000, 1250 ,1600 2000,2500
Keys now perfect work.Video key is use to switch to alt mode.longer press of video key start video record
Raw with DNG work ok now.This Camera use a diffrent Sensor Pattern
as all other Canons, so there is no CRW konverter currently here.
RAW DNG savetime is 1.4 - 1.5 sec(series shoot and use new chdk doublebuffer feature) with a sandisk ultra 8 GB 15 Mb/sec(write bench show 12 megabyte, but its only a class 4 Card.).with CRW savetime is 1.2 -1.3 sec, so not very important to have CRW here.
Auto chdk Boot of Camera does work(test on a 4 GB Card only)
scripts do work(also intervalscripts that do shoot), text output of scripts is now too show.problem was
whats currently not working see here
Status 12.2010 ******************************************************************
chdk usable features.
GUI Layout Editor.Battery % Show, Histogramm, DOF Calculation, Super Fine JPG Save Mode, zoom Value.
when you set the 16:9 (wide) shooting mode, Overexpose/underexpose Dot work in Historgramm and Edge Overlay work too.seem chdk do not handle diffrent shooting modes as 4:3 shoot mode on a 16:9 display and 16:9 shoot mode on 16:9 display
alt key Mode work not very good due to problem in alt or normal key mode.when you leave chdk alt mode, you need press this keys(left, right, down, up, menu, set) (you need not press all together) so the firmware can recognize keys again.
in alt mode, do not work to hide keypress from the firmware rom correct.so better avoid to use the alt mode if possible.
The port do no random crash so can use.
whats not working but important.
print show no text in scripts, so can not see if a script correct work or not.
RAW in crw cant open by any program
RAW in dng can not save because badpixel.lua not work correct
raw image with badpixel.bin from SX210 show wrong colors.
Grid overlay is wrong center in 4:3 shoot mode and in 16:9 shoot mode its too small in X
In the 100d Firmware video patches are deactivate