800k samples/sec in a pc-scope

[bluemonday]

i have seen a pc-scope claiming to have 800ksamples in the internet and it is using pic18f2550.. i have read the data sheet of the mcu and im confused if 800ksamples/sec is true.. the scopes website is www.scopedem.com someone tell me how they did it?

 

[xorcise]

scope with 18f2550

They are likely implementing an external ADC. Offhand I don't think the 18F2550's manage even 100K samples. You can speed it up by reducing the resolution of the samples, but not anywhere close to 800K samples.

We use the 18F2550 in our USB Semiconductor Curve Tracer... a very nice PIC:

**broken link removed**

Added after 11 minutes:

I looked at the link and think the claims are not good. For instance, they mention shared sampling rate. That's not possible with a single 18F2550 since the ADC's are multiplexed and each must timeslice and take a turn. I don't understand how 80KHz turns into 800K samples, and so on.