Re: VIA shift register

From: Pasi 'A1bert' Ojala <*a1bert_at_iki.fi*> Date: Thu, 10 Jan 2019 18:22:54 +0200 Message-ID: <1c6d6084-c3cb-ca8a-fa73-aa0346f66007@iki.fi> · a1bert_at_iki.fi

On 10.01.2019 17:22, smf wrote:
> On 10/01/2019 08:11, André Fachat wrote:
>> I know this solution, but IIRC this prevents bidirectional operation 
>> without extra direction control.
>
> Don't the c128 & 1571 have extra hardware for direction control on the 
> 6526 ?

http://www.iki.fi/a1bert/Dev/burst (already mentioned earlier, but this 
is the "forever link"):

"The C128 hardware includes a buffer driver between SRQ and the cassette 
read line so that cassette activity or cassette drive presence will not 
disturb the fast serial port. It also has a two-directional buffer that 
connects SRQ and DATA to the CIA1 synchronous serial port. The direction 
is controlled by the MMU chip. These buffers are required to hide the 
fast serial connection is C64 mode."

-Pasi