My poor choice of terminology. For want of a better term I refer to the internal serial memory chip as a virtual SD memory card, and that serial memory chip is only 16Mbits = 2Mbytes. The Quad firmware emulates an SD memory card reader (2Mbyte) to any PC connection while the Quad is in normal mode of operation.
The Nano has an internal Flash memory plus a plug in SD memory card slot for cards up to 2-Gbytes.
Unfortunately the Quad design chose small over functional and had not enough room for the SD card. I am sure they were also trying to keep the cost down. This has resulted in serious memory shortage for typical DSO o’scope uses such as saving multiple capture buffers and multiple configuration sets, not to mention BMP screen saves.
If you can live with the Nano narrow bandwidth, it is a much better product than the Quad when the Nano is using the latest BenF firmware updates. Hopefully Bure and associates will take heed and update the Quad to include a new software trigger system that works properly and to also incorporate the BenF features that already exist in the Nano. I have said all this before, but maybe persistence will prevail. It just doesn’t make sense to totally ignore 6-months of firmware user interface development on the Nano while creating the factory Quad firmware which uses the same processor family. 