Got one of this unit with the intention to make custom version of it --as it is missing the CPU board--, so i dug deeper in the HW:
1) LCD is a 480x272 @24bit HannStar HSD043I9W1-A
2) the USB Hub IC controls the Power to the devices downstream through some switches/w o.c. detection (TPS2062/TPS2042)
3) LEDs, buttons, potentiometers and encoder handled by a MCF51QE128 ColdFire MCU
4) Jogs are made from 2 types of sensors both connected to the ColdFire:
-a high speed/low resolution optical mirror/stripes (led+photo detector)
-a low speed high resolution optical mouse sensor (ADNS5050)
5) touch detection is by IDT LDS6201 chip (i2c connected to the ColdFire)
6) sound ADC and DAC through i2s interface DACs: AK4388 / ADC: AK5358 -- separate i2s data for all
7) there is an S35390A RTC
6) cpu-card and digital board-to-board connector has been mapped as attachments
(interestingly the digital b2b connector has more pins to the ColdF than what actually connects to the CPU board)
So the plan is to use an Orange Pi One, connect the usb otg to the device-usb, one usb host to the Hub, convert the Pi's HDMI to TTL by a VS-TY2662-V2 board.
Then config the DACs to one Left-justified and one Right-justified then drive them both from the same I2S (the H3 supports more packets on a single I2S bus -- as the 2nd port is not fully available /cannot sync up with the first/)
Finally there would be need for the ColdFire communication --maybe reverseable from the system update firmware. Alternatively can be remade from scratch..