>>I've seen a lot of ads on the various mac sites for USB to serial
>>converters. I've been wondering why, since most serial devices depend on
>>two-way communication, these converters couldn't also be serial to USB
>>converters, allowing us to tap into all the new USB peripherals. I'm sure
>>there is a simple reason, but I'd appreciate it if someone would elucidate.
>
>Relative speed. USB runs at a peak (burst) speed of 12 megabits/s. Without
>getting into an explanation of asynchronous vs. synchronous operation, the
>serial port on a Mac can be run with bursts of 230kb/s max, and the Geoport
>that the 2400 and most other PCI Powermacs have can run at 2MB/s max. Data
>from a USB device would simply overrun the serial port; either data bits
>would be lost or performance would be abysmal with lots of retransmission
>(I need to look at the USB spec s'more to know which :). It might be
>possible to construct an adaptor that would negotiate the speed down or
>provide a lot of internal buffering, but for the kind of performance you'd
>see and the various compatibility problems from the higher latency, it
>wouldn't be worth it.
>
>The same would apply to a USB to Firewire convertor, or a USB to SCSI
>convertor, because both of those standards are substantially faster than
>USB-1. It'd be possible to come up with something that would work
>occasionally, but it's just the wrong solution.
Would the above said also apply to such a device as the Imation (sony?)
drive that can read/write 1,4MB floppies (and faster than Apple�s drive)
as well as its own 120 MB media? To be able to connect my PB 2300 to this
drive (via micro dock, scsi or floppy) or to mount it to a DuoDock would
be just great - two storage devices in one... Can this be done?
Edgar
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