The Z-80 SoftCard is a plug-in Apple II processor card developed by

Microsoft Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

to turn the computer into a

CP/M CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/Intel 8085, 85-based microcomputers by Gary Kildall of Digital Research, Dig ...

system based upon the

Zilog Z80 The Zilog Z80 is an 8-bit computing, 8-bit microprocessor designed by Zilog that played an important role in the evolution of early personal computing. Launched in 1976, it was designed to be Backward compatibility, software-compatible with the ...

central processing unit (CPU). Becoming the most popular CP/M platform and Microsoft's top revenue source for 1980, it was eventually renamed the Microsoft SoftCard, and was succeeded by Microsoft's Premium Softcard IIe for the Apple IIe.

Overview

Released on April 2, 1980 as Microsoft's first hardware product, the Z-80 SoftCard is an Apple II processor card that enables the

Apple II Apple II ("apple Roman numerals, two", stylized as Apple ][) is a series of microcomputers manufactured by Apple Computer, Inc. from 1977 to 1993. The Apple II (original), original Apple II model, which gave the series its name, was designed ...

to run

, an operating system from Digital Research. This gives Apple II users access to many more business applications, including compilers and Interpreter (computing), interpreters for several high-level languages. CP/M, one of the earliest cross-platform operating systems, is easily adaptable to a wide range of auxiliary chips and peripheral hardware, but it requires an

Intel 8080 The Intel 8080 is Intel's second 8-bit computing, 8-bit microprocessor. Introduced in April 1974, the 8080 was an enhanced successor to the earlier Intel 8008 microprocessor, although without binary compatibility.'' Electronic News'' was a week ...

-compatible CPU, which the Zilog Z80 is, but which the Apple's CPU, the

MOS Technology 6502 The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit computing, 8-bit microprocessor that was desi ...

, is not. The SoftCard has a

CPU plus some 74LS00 series TTL chips to adapt that processor's

bus A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a motor vehicle that carries significantly more passengers than an average car or van, but fewer than the average rail transport. It is most commonly used ...

to the Apple bus. As CP/M requires contiguous freely usable

RAM Ram, ram, or RAM most commonly refers to: * A male sheep * Random-access memory, computer memory * Ram Trucks, US, since 2009 ** List of vehicles named Dodge Ram, trucks and vans ** Ram Pickup, produced by Ram Trucks Ram, ram, or RAM may also ref ...

from address zero - which the Apple II does not have, since its own 6502 CPU's

call stack In computer science, a call stack is a Stack (abstract data type), stack data structure that stores information about the active subroutines and block (programming), inline blocks of a computer program. This type of stack is also known as an exe ...

and zero page and its

text mode Text mode is a computer display mode in which content is internally represented on a computer screen in terms of characters rather than individual pixels. Typically, the screen consists of a uniform rectangular grid of ''character cells'', ea ...

screen memory cannot be outside the lowest 4 KiB of RAM - addresses are translated in order to move reserved-RAM and non-RAM areas to the top of memory. The card was bundled with CP/M and the

Microsoft BASIC Microsoft BASIC is the foundation software product of the Microsoft company and evolved into a line of BASIC interpreters and compiler(s) adapted for many different microcomputers. It first appeared in 1975 as Altair BASIC, which was the first v ...

programming language.

History

The SoftCard was

Paul Allen Paul Gardner Allen (January 21, 1953 – October 15, 2018) was an American businessman, computer programmer, and investor. He co-founded Microsoft, Microsoft Corporation with his childhood friend Bill Gates in 1975, which was followed by the ...

's idea. Its original purpose was to simplify

porting In software engineering, porting is the process of adapting software for the purpose of achieving some form of execution in a computing environment that is different from the one that a given program (meant for such execution) was originally desig ...

Microsoft's computer-language products to the Apple II. The SoftCard was developed by

Tim Paterson Tim Paterson (born 1 June 1956) is an American computer programmer, best known for creating 86-DOS, an operating system for the Intel 8086. This system emulated the application programming interface (API) of CP/M, which was created by Gary Kilda ...

Seattle Computer Products Seattle Computer Products (SCP) was a Tukwila, Washington, microcomputer hardware company which was one of the first manufacturers of computer systems based on the 16-bit Intel 8086 processor. Founded in 1978, SCP began shipping its first S ...

(SCP). SCP built prototypes, Don Burtis of Burtronix redesigned the card, and California Computer Systems manufactured it for Microsoft. Unsure whether the card would sell, Microsoft first demonstrated it publicly at the

West Coast Computer Faire The West Coast Computer Faire was an annual computer industry conference and exposition most often associated with San Francisco, its first and most frequent venue. The first fair was held in 1977 and was organized by Jim Warren (computer specia ...

in March 1980. Microsoft also released a version for the

Apple IIe The Apple IIe (styled as Apple //e) is the third model in the Apple II series of personal computers produced by Apple Inc., Apple Computer. It was released in January 1983 as the successor to the Apple II Plus. The ''e'' in the name stands for ...

, the Premium Softcard IIe. The card has functionality equivalent to the Extended 80-Column Text Card, including its 64 KB RAM, so would save money for users who wanted CP/M capability, additional memory, and 80-column text.

Reception

''Compute!'' witnessed the SoftCard's debut in March 1980 at the West Coast Computer Faire, calling it "an Apple breakthru". ''

InfoWorld ''InfoWorld'' (''IW'') is an American information technology media business. Founded in 1978, it began as a monthly magazine. In 2007, it transitioned to a Web-only publication. Its parent company is International Data Group, and its sister pu ...

'' in 1981 called the SoftCard "a fascinating piece of hardware". While criticizing the "computerese" of the CP/M documentation, the magazine wrote "if you need a lightweight, portable Z80 computer, the Apple/SoftCard combination is a perfect pair." ''

BYTE The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable un ...

'' wrote, "Because of the flexibility that it offers Apple users, I consider the Softcard an excellent buy .. The price is reasonable, and it works". ''InfoWorld'' in 1984 also favorably reviewed the SoftCard IIe, approving of its ability to also replace the Extended 80-Column Text Card. The magazine concluded that it "is a good system among several good systems on the market", especially for those who wanted to run Microsoft BASIC or wanted functionality beyond CP/M.

Sales

The SoftCard's immediate success surprised Microsoft. Although unprepared to take orders at the West Coast Computer Faire, a Microsoft executive accepted 1,000 business cards from interested parties on the first day; ''Compute!'' reported that the company was "inundated" with orders. The SoftCard became the company's largest revenue source in 1980, selling 5,000 units in three months at $349 each, with high sales continued for several years. For a while, the SoftCard was the single most-popular platform to run CP/M, and Z-80 cards became very popular Apple II peripherals. By 1981 Microsoft,

Lifeboat Associates Lifeboat Associates, Inc., was a New York City company that was one of the largest microcomputer software distributors in the late 1970s and early 1980s. Lifeboat acted as an independent software broker marketing software to major hardware vend ...

, and Peachtree Software published their CP/M software on Apple-format disks, and Microsoft stated in 1982 that one fifth of all Apple IIs used the Microsoft SoftCard.

Alternatives

Following Microsoft's success, several other companies developed Z80 cards for the Apple II as well, including Digital Research with and a CP/M card developed by Advanced Logic Systems (ALS) named "The CP/M Card" (with a 6 MHz Z80 and 64 kB RAM) and Digital Research's CP/M Gold Card for CP/M Pro 3.0 (with 64 or 192 kB RAM). Microsoft sued ALS in February 1982 for copying its

BIOS In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is a type of firmware used to provide runtime services for operating systems and programs and to perform hardware initialization d ...

.Other independent designs came from Applied Engineering, PCPI (with their 6 MHz Appli-Card), Cirtech, and IBS. There were also about a dozen SoftCard clone manufacturers. Microsoft announced a SoftCard for the

Apple III The Apple III (styled as apple ///) is a business-oriented personal computer produced by Apple Computer and released in 1980. Running the Apple SOS operating system, it was intended as the successor to the Apple II; however, it was largely cons ...

in June 1982, stating that it would be available in October. The Xedex Baby Blue CPU Plus card provides similar functionality to the

IBM PC The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the List of IBM Personal Computer models, IBM PC model line and the basis for the IBM PC compatible ''de facto'' standard. Released on ...

, allowing that computer to run CP/M-80 software like

WordStar WordStar is a discontinued word processor application for microcomputers. It was published by MicroPro International and originally written for the CP/M-80 operating system (OS), with later editions added for MS-DOS and other 16-bit computing, ...

; the Baby Tex is the TI Professional version. The first version of the Diamond Computer Systems Trackstar, an Apple II emulation card for the PC, includes a Z80 and also supports CP/M.

References

External links

AppleLogic website
showing peripheral cards for the Apple II, including the Microsoft Softcard {{Microsoft hardware Apple II family Compatibility cards Computer-related introductions in 1980 Microsoft hardware