Apple II system clocks

Last updated September 26, 2024

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 productivity programs as well as the ProDOS operating system implemented time and date functions, users would have to manually enter this information every time they turned the computer on. Power users often had their Apple II's peripheral slots completely filled with expansion cards, so third party vendors came up with alternative approaches with products like the Serial Pro and No-Slot Clock.

No-Slot Clock (Dallas Semiconductor)

The No-Slot Clock, also known as the Dallas Smartwatch (DS1216E),^[1] was a 28-pin chip-like device that could be used directly in any Apple II or Apple II compatible with a 28-pin ROM. Dallas Semiconductor produced the device as an easy implementation for a real-time clock for a variety of applications. The clock was powered by an embedded lithium battery, electrically disconnected until power was first applied to retain freshness. The non-replaceable battery had a life expectancy of 10 years.

In an Apple II, the No-Slot Clock resided under any 28-pin ROM chip, including one on a peripheral card. A user had to remove the ROM from its socket, insert the No-Slot Clock, and then reinsert the ROM chip into the top of the No-Slot Clock. The No-Slot Clock was both ProDOS and DOS 3.3 compatible, however a software driver had to be patched into ProDOS or integrated into the applicable DOS 3.3 program. Once the driver was installed it emulated the Thunderclock. The No-Slot Clock was usually installed in the following locations on the motherboard in the following computers:^[2]

Apple IIe: under the CD ROM (or CF ROM in later models)
Apple IIc: under the Monitor ROM
Apple IIc+: under the Monitor ROM
Laser 128: under the ROM behind the metal cover on the bottom

Serial Pro (Applied Engineering)

The Serial Pro was a multifunction serial interface and clock/calendar card from Applied Engineering. By combining the functions of two cards into one, the Serial Pro freed 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. The card was capable of a 12‑ and 24‑hour clock format, was both ProDOS and DOS 3.3 compatible, and had on-screen time and date setting built into its ROM, eliminating the need to run a program in order to set the time. The battery was a GE DataSentry rechargeable Ni-cad battery which had a lifespan rating of 20 years. The card retailed for $139 during the late 1980s.^[3]

For more on the Serial Pro's communication capabilities, see its entry in Apple II serial cards.

Thunderclock Plus (Thunderware Incorporated)

When the Thunderware Thunderclock Plus was released in 1980,^[4] it quickly became the de facto standard for an Apple II system clock. When Apple Computer released its new ProDOS operating system in 1984, a Thunderclock software driver came built-in. From that point on, all new Apple II system clocks strived to emulate the Thunderclock. The card itself was more compact than the earlier "The Clock" from Mountain Computer and contained two battery holders for off the shelf alkaline batteries which were easily replaceable.

Time Master H.O. (Applied Engineering)

The Time Master H.O. clock card from Applied Engineering was possibly the most advanced system clock ever designed for any Apple II. The card utilized an onboard VIA 6522 and was capable of emulating all other system clocks which preceded it. The Timemaster H.O. was powered by a GE Datasentry rechargeable Ni-cad battery which had a lifespan rating of 20 years. It was capable of 24‑hour format or 12‑hour with AM/PM format, millisecond timekeeping with an accuracy of 0.00005%, and an onboard timer which could time down any interval up to 48 days. It also maintained an internal calendar, separate of the 7‑year cycle which ProDOS mapped. The Timemaster H.O. was 100% ProDOS and DOS 3.3 compatible.

The "H.O." in Timemaster H.O. stood for "High Output". This referred to the 8-pin Digital I/O port on the card for advanced applications. Through this port, one could hook up Applied Engineering's BSR X-10 interface and "command console" to remotely control lights and electrical appliances. The BSR system could send signals over existing 120‑volt wiring, eliminating the need for additional wires. The system could also be used for low‑voltage implementations. The Timemaster H.O. retailed for $99 during the late 1980s while the BSR option cost an additional $29. The command console cost $39.^[3]

Other system clocks

AppleClock (Mountain Computer)
California Computer Systems Clock (California Computer Systems)
CPS Multifunction Card (Mountain Computer)
The Clock (Mountain Computer)
Timemaster II H.O. (Applied Engineering)
Hayes Stack Chronograph (Hayes Microcomputer Products)
Time II (Applied Engineering)
VersaCard (Prometheus Products)
The Cricket! (Street Electronics)
Clockworks (Micro Systems Research)
SUPERCLOCK II (West Side Electronics)
ProCLOCK (Practical Peripherals)
N-Clock-Uhrkarte (Unknown)
APPLE TimePiece (Comrex International)

Related Research Articles

The Apple II series of microcomputers was initially designed by Steve Wozniak, manufactured by Apple Computer, and launched in 1977 with the Apple II model that gave the series its name. It was followed by the Apple II Plus, Apple IIe, Apple IIc, and Apple IIc Plus, with the 1983 IIe being the most popular. The name is trademarked with square brackets as Apple ][, then, beginning with the IIe, as Apple //. In terms of ease of use, features, and expandability, the Apple II was a major advancement over its predecessor, the Apple I, a limited-production bare circuit board computer for electronics hobbyists.

<span class="mw-page-title-main">Motherboard</span> Main printed circuit board used for a computing device

A motherboard is the main printed circuit board (PCB) in general-purpose computers and other expandable systems. It holds and allows communication between many of the crucial electronic components of a system, such as the central processing unit (CPU) and memory, and provides connectors for other peripherals. Unlike a backplane, a motherboard usually contains significant sub-systems, such as the central processor, the chipset's input/output and memory controllers, interface connectors, and other components integrated for general use.

The Tandy 1000 was the first in a series of IBM PC compatible home computers produced by the Tandy Corporation, sold through its Radio Shack and Radio Shack Computer Center stores. Introduced in 1984, the Tandy 1000 line was designed to offer affordable yet capable systems for home computing and education. Tandy-specific features, such as enhanced graphics, sound, and a built-in joystick port, made the computers particularly attractive for home use.

The Apple IIe is the third model in the Apple II series of personal computers produced by Apple Computer. It was released in January 1983 as the successor to the Apple II Plus. The e in the name stands for enhanced. It is the first Apple II with built-in lowercase and 80-column text support, as well as 64K RAM, while reducing the total chip count from previous models by approximately 75%.

<span class="mw-page-title-main">Expansion card</span> Circuit board for connecting to a computer system to add functionality

In computing, an expansion card is a printed circuit board that can be inserted into an electrical connector, or expansion slot on a computer's motherboard to add functionality to a computer system. Sometimes the design of the computer's case and motherboard involves placing most of these slots onto a separate, removable card. Typically such cards are referred to as a riser card in part because they project upward from the board and allow expansion cards to be placed above and parallel to the motherboard.

The Apple IIe Card is a compatibility card, which through hardware and software emulation, allows certain Macintosh computers to run software designed for the Apple II. Released in March 1991 for use with the LC family, Apple targeted the card at its widely dominated educational market to ease the transition from Apple II-based classrooms, with thousands of entrenched educational software titles, to Macintosh-based classrooms.

The Apple IIGS is a 16-bit personal computer produced by Apple Computer. It is the fifth and most powerful of the Apple II family. It is compatible with earlier Apple II models, but has a Macintosh look and feel, and resolution and color similar to the Amiga and Atari ST. The "GS" in the name stands for "Graphics and Sound", referring to its enhanced multimedia hardware, especially its state-of-the-art audio.

The Apple IIc is a personal computer introduced by Apple Inc. shortly after the launch of the original Macintosh in 1984. It is essentially a compact and portable version of the Apple IIe. The IIc has a built-in floppy disk drive and a keyboard, and was often sold with its matching monitor. The c in the name stands for compact, referring to the fact it is a complete Apple II setup in a smaller notebook-sized housing. It is compatible with a wide range of Apple II software and peripherals.

The Mockingboard is a sound card built by Sweet Micro Systems for the Apple II microcomputers. It improves on the Apple II's limited sound capabilities, as did other Apple II sound cards.

The Gravis UltraSound or GUS is a sound card for the IBM PC compatible system platform, made by Canada-based Advanced Gravis Computer Technology Ltd. It was very popular in the demoscene during the 1990s.

The Laser 128 is an Apple II clone, released by VTech in 1986 and comparable to the Apple IIe and Apple IIc.

Applied Engineering, headquartered in Carrollton, Texas, was a leading third-party hardware vendor for Apple II computers from the early 1980s until the mid-1990s.

<span class="mw-page-title-main">Commodore 64 peripherals</span>

The Commodore 64 home computer used various external peripherals. Due to the backwards compatibility of the Commodore 128, most peripherals would also work on that system. There is also some compatibility with the VIC-20 and Commodore PET.

The Apple IIc Plus is the sixth and final model in the Apple II series of personal computers, produced by Apple Computer. The "Plus" in the name was a reference to the additional features it offered over the original portable Apple IIc, such as greater storage capacity, increased processing speed, and a general standardization of the system components. In a notable change of direction, the Apple IIc Plus, for the most part, did not introduce new technology or any further evolutionary contributions to the Apple II series, instead merely integrating existing peripherals into the original Apple IIc design. The development of the 8-bit machine was criticized by quarters more interested in the significantly more advanced 16-bit Apple IIGS.

The Macintosh Quadra 605 is a personal computer designed, manufactured, and sold by Apple Computer from October 1993 to July 1996. The model names reflect a decision made at Apple in 1993 to follow an emerging industry trend of naming product families for their target customers – Quadra for business, LC for education, and Performa for home. Accordingly, the Performa 475 and 476 was sold in department stores and electronics stores such as Circuit City, whereas the Quadra was purchased through an authorized Apple reseller.

The Amiga computer can be used to emulate several other computer platforms, including legacy platforms such as the Commodore 64, and its contemporary rivals such as the IBM PC and the Macintosh.

The Disk II Floppy Disk Subsystem, often rendered as Disk ][, is a 5 +1⁄4-inch floppy disk drive designed by Steve Wozniak at the recommendation of Mike Markkula, and manufactured by Apple Computer It went on sale in June 1978 at a retail price of US$495 for pre-order; it was later sold for $595 including the controller card and cable. The Disk II was designed specifically for use with the 1977 Apple II personal computer to replace the slower cassette tape storage.

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 functionality of the base motherboard when paired with specialized software that enabled the computer to read the input/output of the devices on the other side of the cable or to take advantage of chips on the board - as was the case with memory expansion cards.

Apple II serial cards primarily use the serial RS-232 protocol. They most often were used for communicating with printers, Modems, and less often for computer to computer data transfer. They can be programmed to interface with any number of external devices which were RS-232 compatible. Most serial cards have speed ranges starting from 110 bit/s up to 19,200 bit/s, however some can 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 accelerators are computer hardware devices which enable an Apple II computer to operate faster than their intended clock rate.

References

↑ "SmartWatch RAM (DS1216B/C/D/H); SmartWatch ROM (DS1216E/F)" (PDF). analog.com. Retrieved 10 May 2023.
↑ apple2.org: Apple Reference Web
1 2 Applied Engineering Spring/Summer '88 Catalog
↑ Manual for DOS support and ProDOS support