Re: Commodore drives can be controlled on Apple II serial!

[supertimer@aol.com (Supertimer)]

doug.cotton@cmdweb.com (Doug Cotton) wrote:

>dempson@actrix.gen.nz (David Empson) wrote:
>
>> SmartPort is serial, not parallel.  It also has several major
>> limitations: all data bytes transferred must have bit 7 set, and the
>> data rate is fixed (4 microseconds per bit cell, or 2 microseconds for
>> Apple 3.5 drives).
>> 
>> The only exception to this is the phase lines, which give you a four-bit
>> parallel output that can be controlled directly by software, and
>> probably the sense line, which gives you a one bit direct input.
>
>That last bit is interesting... standard Commodore serial I/O only uses
>three lines... ATN (Attention), CLK (Clock) and DATA (Serial Data). The
>other three lines on the bus are a ground, reset and SRQ (Service Request).
>The latter is needed for fast serial only, though schemes like JiffyDOS
>perform (sometimes outperform) fast serial without even using this line.

So, based on what David wrote about the SmartPort, can it be used to
emulate Commodore serial I/O?