:''This article is a sub-page of

Apple II peripheral cards The Apple II line of computers supported a number of Apple II peripheral cards. In an era before plug and play USB or Bluetooth connections, these were expansion cards that plugged into slots on the motherboard. They added to and extended the functi ...

.'' Apple II serial cards primarily used the serial

RS-232 In telecommunications, RS-232 or Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a ''DTE'' ('' data terminal equipment'') suc ...

protocol. They most often were used for communicating with printers,

Modems A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by modulating one or more carr ...

, and less often for computer to computer data transfer. They could be programmed to interface with any number of external devices which were RS-232 compatible. Most serial cards had speed ranges starting from 110

bit/s In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time. The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction w ...

up to 19,200 bit/s, however some could be modified to go much faster. The most popular and widely used of these cards was Apple Computer's Super Serial Card, a solid design that was often copied for maximum software compatibility of the end product.

Apple II Communications Card – ''Apple Computer''

The Apple II Communications Card is the original serial card from

Apple Computer Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company ...

. Released in 1978 for $225, it was designed to work with

modems A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by modulating one or more carr ...

utilizing

acoustic coupler In telecommunications, an acoustic coupler is an interface device for coupling electrical signals by acoustical means—usually into and out of a telephone. The link is achieved through converting electric signals from the phone line to sound ...

s. It offered speeds of 110 and 300

but with a simple hardware modification (described in the manual accompanying the card) one could change this to 300 and 1200 bit/s, or 1200 and 4800 bit/s.

Apple II Serial Interface Card – ''Apple Computer''

The Apple II Serial Interface Card was released by Apple Computer shortly after the Communications Card, in August 1978. Designed for printing, this card had ROM revisions, P8 and P8A. The P8A ROM supported handshaking while the earlier P8 rom didn't. Unfortunately the P8A ROM revision was not compatible with some printers that worked under the original P8 ROM.

Serial Pro – ''Applied Engineering''

The Serial Pro serial interface card from

Applied Engineering Applied Engineering, headquartered in Carrollton, TX, was a leading third-party hardware vendor for the Apple II series of computers from the early 1980s until the mid-1990s. History {{original research, section, date=September 2018 In its da ...

was compatible with the Apple Super Serial Card. Unlike the Apple SSC, which used a jumper block to select printer mode or modem mode, the Serial Pro board had two connectors to which the card's ribbon cable could be connected, one for use with a printer and one for use with a modem. The Serial Pro was a multifunction card which included a

ProDOS ProDOS is the name of two similar operating systems for the Apple II series of personal computers. The original ProDOS, renamed ProDOS 8 in version 1.2, is the last official operating system usable by all 8-bit Apple II series computers, and w ...

and DOS 3.3 compatible clock/calendar, freeing up an extra slot for those with highly populated machines. This card was unique in the sense that it did not use "Phantom Slots" to achieve this functionality. Previous multifunction cards required that a secondary function be "mapped" to a different slot in the computer's memory, rendering that slot unusable. If used with a

dot-matrix printer A dot matrix printer is an impact printer that prints using a fixed number of pins or wires. Typically the pins or wires are arranged in one or several vertical columns. The pins strike an ink-coated ribbon and force contact between the ribbon ...

, the Serial Pro offered several screen-print variations. It could print either HiRes page (or both in a single dump) normally, or print page one rotated or inverted. The Serial Pro utilized the MOS Technology 6551 ACIA chip and offered serial baud rates from 50 bit/s to 19,200 bit/s. The lifespan of the card's battery (which retained configuration information and powered the clock chip when the computer was powered off) was touted as 20 years. The card retailed for $139 during the late 1980s.Applied Engineering Spring/Summer '88 Catalog ''For more on the Serial Pro's clock capabilities, see its entry in

Apple II system clocks Apple II system clocks, also known as real-time clocks, were devices in the early years of microcomputing. A clock/calendar did not become standard in the Apple II line of computers until 1986 with the introduction of the Apple IIGS. Although many ...

.''

Super Serial Card – ''Apple Computer''

Apple Computer's Super Serial Card, sometimes abbreviated as "SSC", is the most well known communication card made for the Apple II. Apple called it "Super" because it was able to function as both of Apple's previous cards, the Apple II Communications Card for modem use and the Apple II Serial Interface Card for printer use. A jumper block was used to configure the card for each of the two modes. The card has a maximum speed of 19,200 bit/s and is compatible with both ROM revisions of the Apple II Serial Interface Card. Reliable communications at 9600 bit/s and higher required disabling of interrupts. The card can actually run at 115,200 bit/s as well, using undocumented register settings; but speeds ''between'' 19,200 and 115,200 are not possible using this technique. The Super Serial Card was released in 1981 and utilizes the MOS Technology 6551 ACIA serial communications chip.

Other serial cards

''Use this article for: Apple II multi I/O cards * 7710 Serial Interface – ''California Computer Systems'' * 7711 Super Serial Interface – ''California Computer Systems'' * AIO Interface – ''SSM or Transend'' * ASIO Interface – ''SSM or Transend'' * Alphabits – ''Street Electronics'' * Serial Interface – '' Apricorn'' * Multicore – '' Quadram'' * SV-622 Serial Interface – ''Microtek'' * SeriALL – ''Practical Peripherals'' * Serial Interface DK 244 – ''Digitek International Ltd'' * Super Serial Board – ''MC Price Breakers'' – Generic Super Serial Card clone * Super Serial Imager – ''Apricorn'' * Super-COMM – ''Sequential Systems'' – SSC compatible, built in term program in ROM, supported grappler screen dumps and graphics. * Versacard – ''Prometheus Products Inc.'' * MasterCard II – ''Pace electronics.'' 6850 based serial port with a 6522 user port to drive autodial modems. Simple terminal program included in onboard EPROM

References

{{Apple hardware Apple II peripherals