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worlickwerx / pi-parport

retro parallel port for raspberry pi
GNU General Public License v2.0
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Advise for possible use for Diamond Rio MP3 player #58

Closed deanhuff closed 3 years ago

deanhuff commented 3 years ago

I have been investigating using GPIO pins to a DB25 breakout board along with SMI (secondary memory interface) to implement a parallel port so that I can upload/download music to my MP3 player from 1998. Source code to the mp3 software is still maintained in debian rio package here: https://sources.debian.org/src/rio/1.07-14/ pertinent info is in rio.txt.

do you think a pi-parport would be a good option?

garlick commented 3 years ago

A quick scan of the code shows it uses outb() / inb() to access the parallel port directly from user space.

That doesn't work with pi-parport - it would need to be converted to use ppdev ioctls, and then it may or may not work. ppdev adds latency compared to memory mapped I/O but that is mitigated somewhat by the fact that the pi may be faster at some things than a PC of 1998.

deanhuff commented 3 years ago

understood, thanks for the reply.