I have looked into useing the Soundblaster 128 as a simple dso/logic analyzer.
Seems it's constructed with a main controller chip "Creative 5507" which have
a LRCK,SCLK,SDI link to the mixer which contains the A/D (limited to 50kHz).
The card have a 22.5792 MHz crystal that correspond 32x the max theoretical
samplerate of 705600 Hz (found out by driver source). The audio and pci part
is on separate clock domains I presume aswell.
http://www.hardwarehistory.com/images/oldhard/sound/ct4700.jpg
http://www.hh.iij4u.or.jp/~tokumi/pict/PCI128_2.JPG (removed chips)
By replaceing the A/D it ought to be possible to raise the maximum samplerate
to 705600 Hz. And by replaceing the 22.5792 MHz crystal it should be possible
to raise it even more. However it becomes dependent on the way the chip is
manufactured and possible pci interface issues. Any ideas on how high one
can clock this chip ..?
/Peter
Seems it's constructed with a main controller chip "Creative 5507" which have
a LRCK,SCLK,SDI link to the mixer which contains the A/D (limited to 50kHz).
The card have a 22.5792 MHz crystal that correspond 32x the max theoretical
samplerate of 705600 Hz (found out by driver source). The audio and pci part
is on separate clock domains I presume aswell.
http://www.hardwarehistory.com/images/oldhard/sound/ct4700.jpg
http://www.hh.iij4u.or.jp/~tokumi/pict/PCI128_2.JPG (removed chips)
By replaceing the A/D it ought to be possible to raise the maximum samplerate
to 705600 Hz. And by replaceing the 22.5792 MHz crystal it should be possible
to raise it even more. However it becomes dependent on the way the chip is
manufactured and possible pci interface issues. Any ideas on how high one
can clock this chip ..?
/Peter
