ajross wrote:Hi - I'm after an RS232 (serial) adapter card for an Apple //e, ideally with a 16550(A?) UART, but 8250 will also be OK.
Aj, unless you have something
very special in mind, I think you might be mixing your genre's there. The 16550 vs 8250 issue was a buffer length difference pertaining to >28.8k modem thing (i.e. 115k DTE speed) from the 486 era.
The UART is not really your limiting factor on the IIe. I've read fairly well optimised ASM serial code that tops out at about 56kbit with even a basic demonstration loop. Admittedly, bit banging is going to be slower than a byte UART, but I suspect you would struggle to saturate even an 8250 on the 1MHz 6502.
In any case, I don't think I've ever seen a serial for the Apple II using the IBM PC style (byte) UARTS, so probably no software will support it.
UPDATE: The closest thing I've seen so far to a 16550 UART on an Apple II is someone
suggesting it might be possible to build one.
The regular Apple "super serial" is pretty much universally supported and capable of a wide speed range. ADT Pro at 19.2kbit will fill a 140k floppy in a matter of seconds. What are you wanting to do?