GeoPort is a serial data system used on some models of the Apple Macintosh that could be externally clocked to run at a 2 megabit per second data rate. GeoPort slightly modified the existing Mac serial port pins to allow the computer's internal DSP hardware or software to send data that, when passed to a digital-to-analog converter, emulated various devices such as modems and fax machines. GeoPort could be found on late-model 68K-based machines (the AV series) as well as many pre-USB Power Macintosh models and PiPPiN. Some later Macintosh models also included an internal GeoPort via an interna
GeoPort is a serial data system used on some models of the Apple Macintosh that could be externally clocked to run at a 2 megabit per second data rate. GeoPort slightly modified the existing Mac serial port pins to allow the computer's internal DSP hardware or software to send data that, when passed to a digital-to-analog converter, emulated various devices such as modems and fax machines. GeoPort could be found on late-model 68K-based machines (the AV series) as well as many pre-USB Power Macintosh models and PiPPiN. Some later Macintosh models also included an internal GeoPort via an internal connector on the Communications Slot. Apple GeoPort technology is now obsolete, and modem support is typically offered through USB.
==Background== ===AppleBus and LocalTalk=== Early during the development of the Apple Macintosh, Apple engineers decided to use the Zilog 8530 "Serial Communications Controller" (SCC) for most input/output tasks. The SCC was relatively advanced compared to the more common UARTs of the era, offering a number of high-speed modes and built-in software for error checking and similar duties. The speed of the system was based on an external clock signal sent to it by the host platform, normally up to about 1 Mbit/s, which could be "divided down" to run at slower speeds as low as 300 bit/s. The SCC had two channels, which could be run at different speeds, and even different voltages, to allow communications with a wide variety of devices and interfaces.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).