Re: [PARPORT] Buffer read/write verification

Tim Waugh (
Sun, 21 Mar 1999 23:07:06 +0000 (GMT)

On Sun, 21 Mar 1999, Dale Whitfield wrote:

> Now, most communication which results in data for the device only can
> be done in hardware (true ECP) mode. Others, which target the EEPROM,
> must be done using ECP-emulated PS/2 mode with handshaking emulated in
> software. The only difference is timing. This allows, for example,
> time for the data lines to settle during the handshake cycle.

Firstly, if the device is that sensitive to timing, it is not talking
Std-1284 ECP mode. Plain and simple.

Secondly, being able to choose if hardware or software is used for a block
write doesn't help you at all in this situation, because you don't (and
shouldn't have) any control over the timings of either.

> The spec sheet I have here (WinBond W83877F) talks about Command/Data
> in both directions, but...

Yes, I read that too. But read on. (Alternatively, if you're looking
somewhere I didn't, a page number would be nice..)

> You miss the point. You don't know if a manufacturer is making one as
> we speak. Its not a case of catering for chips you know about but
> allowing for functionality that is specified.

I agree that it would be nice to have address read functionality. I don't
believe that it is essential, regardless of whether or not it is


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This archive was generated by hypermail 2.0b3 on Sun 28 Mar 1999 - 17:05:48 EST