Bidirectional PRinter Cables?

[otheos]

Assuming the printer is bidirectional, what do these cables offer?

Also, anyone know what the differences are between ECP and EPP?

Thanks in advance.

________________________
otheos: www.otheos.clara.net (http://www.otheos.clara.net)

[Andy_L]

Some printers send data back to the PC, like status hence bi-directional.

[NDC]

ECP uses a DMA channel and EPP doesn't... EPP and ECP transfer rate is 2Mb, unlike the SPP which is 150K. The bi-directional cables allow 2MB transfer rates unlike standard cables that only allow 150K transfer rates...

But EPP has it's own down side.... It has the same transfer rate as ECP, but it utilizes the processor. To solve that, the Enhanced Capabilities Port was developed. It is equal to EPP, but uses a DMA channel, allowing the data transfer to be done without the use of the PC's processor, raising the computer's performance.

[otheos]

Thank you both for your fast reply.

So does EPP/ECP depend on the cable?

At the moment I have a non-bidirectional cable, will I need one to enable ECP?

Thanks again.

________________________
otheos: www.otheos.clara.net (http://www.otheos.clara.net)

[NDC]

Yes, you will need to buy a bi-directional cable (if you printer didn't already come with one) and enable the printer port mode in the BIOS..... to take advantage of ECP or EPP mode....

[Roy]

Very few cables are NOT bidirectonal. It's just that not all are IEEE certified.

I run my BIOS setting for ECP+EPP because my scanner wants one, and the printer wants the other. Works fine.