I think you're on the mark with your comments. I'm trading off a local mass storage device against a big buffer to allow fully synchronous storage of the input data for later spooling to the PC.

It would take a pretty big buffer, but, it would also require a fair amount of faith in, say, Windows, to get the job done. A data burst will take somewhat less than 10 minutes. Do you suppose that, with the occasional 30-second lapse, Windows can get the job done in the remaining 50 minutes or so, if there's little else going on within the system? I've estimated that transfers into or out of Windows take 25-500 times as long as they "should". I'd speculate that, if there's any justification for that at all, Linux will not necessarily do better.

If the interrupts in DOS are inhibited, the data transfer to memory will keep the memory refreshed, and nothing will interrupt it. Once the transfer is complete, the system clock can be reset and the memory content can be spooled off to HDD. In fact, the system can be rebooted once the data is moved to the local hard disk or other medium.

My observations of USB large-data-block-transfer performance under Windows have been pretty poor, and not particularly easy to produce. The advantage of locally buffering on a HDD is that it becomes a file transfer, provided, of course, that the data collection is done in FAT or NTFS. I'm thinking I need better ideas than what I've cooked up so far. I normally like raw data transfers better than formatted ones, since subsequent processing on the PC is not difficult. Unfortunately, USB, as other protocols, is subject to the vagaries of Windows' priority assignment.

I hope it won't be long before we "get back" the ability to do useful work with a computer system, perhaps not a PC, that doesn't support games and other forms of play more than it supports computing. USB claims to support providing external parallel and serial I/O, but the problems with that approach demonstrated in the queries on 8052.COM have amply demonstrated its weaknesses.

RE