HP Prime wireless kit

[debrouxl]

The Prime's USB controller and software are capable of relatively high transfer rates (for a calculator, that is...), as shown by firmware upgrades of 36+MB being reliably transferred in significantly less time than <~10 MB software updates can be transferred to TI Nspires. My third-party firmware experiments on the Prime would have been downright annoying with Nspire-class transfer rates. Nspire transfer rates are much better than 84+(C)(SE), or to a lower extent, 89T transfer rates, but the OS is also much larger.

However, in standard communication mode, the Prime uses USB HID. The upside of using HID is that unlike the whole series of TI USB-capable calculators and cables and also earlier USB-capable HP calculators (exposing device descriptors in vendor-specific classes), the Prime doesn't require a specific Windows USB driver. Such drivers are a huge pain for users and a support pain for HP, it's a very good thing that the Prime doesn't require them.
The downside of using HID, and therefore interrupt transfer, is that Windows reliably, but randomly, loses data at transfers rates higher than several dozen KB/s.

The Prime remains very unstable after transferring files larger than several hundreds of KBs and unstable when or after executing them, but that's another story...


Without insider information: chances are that the USB issues with Prime hardware revision A, which prompted the making of revision C, have to do more with host / OTG mode usage, e.g. with StreamSmart or wireless cradles as devices, than with device mode usage (the Prime being connected to a computer host).