3 ms·
Most seem to very specifically be IEEE 1284 adapters, rather than actual hardware parallel ports.
by RobotToaster 4y ago
Most seem to very specifically be IEEE 1284 adapters, rather than actual hardware parallel ports.
- 0xcde4c3db 4y agoIEEE 1284 is the relevant standard for "modern" (ECP/EPP) parallel ports, but most adapters only provide that interface on the printer side, not a general-purpose host-side interface to control an IEEE 1284 port.
- mikepavone 4y agoECP and EPP are not really useful for GPIO-style use and even the simpler modes are not really desirable if the adapter is implementing the handshaking in hardware. You really just want to be able to manually control all the bits. The original parallel port (and later integrated ones when set to an appropriate mode in the BIOS) allowed this because it was a very simple device and relied on software to handle things like toggling the data strobe line when a byte was written to the data lines.