Possible to speed up I/O subsystem of 5150?

There was one 8-bit ISA hard disk controller card for the IBM PC or XT that would do a 1:1 interleave, from Patterson Labs. Don't know how they did it, but they worked. They were always unusual, probably impossible to find today, but Google it. RLL was way too fast for the PC/XT bus at 1:1 interleave, but there was at least one 8-bit controller from Seagate that worked with only one 30 MB IDE drive. I don't remember the numbers. They would work with a higher interleave, 3 or 4 sounds about right. Spinrite is great for setting the optimum interleave on any of these. The original Western Digital full-length controller was slowest of all, so anything you replace it with is almost sure to be faster. I think it was an interleave of 5. Plus HardCards are not bad, and turn up occasionally on eBay. You need the floppy disk that goes with them for installation. I can dig out a copy if needed. Paul Pennington Augusta, Georgia