While at a previous employer, Allen had developed a floppy
disk controller and, in early 1980, a prototype hard
disk controller. Both used an unusual, all-digital
phase-locked loop data-separator that he patented. Both controller designs used
GCR-encoding, which supported slightly higher linear densities and enabled higher storage capacities than conventional MFM. During a recession, in December 1980 Allen left that employer to form Tallgrass, with his former employer's permission to take the controller designs and another employee, a programmer, with him. Tallgrass' initial revenue stream in 1981 was provided by a contract with SofTech Microsystems for development of the 68000 interpreter for the
UCSD Pascal software system. Allen had previously written the
6809 interpreter for
UCSD Pascal, before starting Tallgrass. By the spring of 1981 the hard
disk controller design was complete. Tallgrass initially tried marketing Allen's unorthodox hard
disk controller alone, to system manufacturers. In mid-1981 it was decided to instead market a complete, external hard-disk subsystem (hard-drive + controller) to computer dealers. Tallgrass first developed subsystems for the
Xerox 820 computer, for an
Alpha Microsystems computer, and was working on an
Apple IIe version when IBM announced the PC in August 1981. A partner in the local, Lenexa, Kansas
Computerland store, Jim Fricke, gave Allen access to their IBM PC demonstrator when it arrived on a Friday, a few weeks before IBM's PCs became available for sale. Allen needed to develop an interface-card and a device-driver to give the PC a connection to and access to the Tallgrass subsystem. Allen discovered Tallgrass had already developed the
IBM PC DOS device driver. As part of the previous development of its subsystem for the Alpha Microsystems computer, Tallgrass had developed a
device driver for
Seattle Computer Products'
86-DOS operating system. 86-DOS was renamed PC DOS when
Microsoft bought the rights and licensed it to IBM. With information gleaned from Computerland's IBM PC demonstrator, Allen designed and built a prototype interface card over the weekend and successfully tested the card and the PC DOS driver in the store on the following Monday. Tallgrass was able to supply its hard disk subsystems for the PC, in production quantities in November 1981, almost immediately after IBM started revenue shipments of PCs, in October. This was because Tallgrass' product was already in production and needed only the simple interface card and
PC DOS driver software to attach it to the IBM PC. The same Computerland store's other partner, Bruce Burdick, was a member of the Computerland chain's New Products Committee and helped get the Tallgrass product embraced by Computerland nationwide. With IBM's entry into the market, Allen invited a friend, Steven B. Volk to join Tallgrass as Executive V.P. of Sales and Marketing. Volk was Tallgrass' fourth employee, hired at the end of 1981 after he finished dental school. Volk assembled a sales organization and started an advertising campaign, initially incorporating pictures of macaws that he and his wife raised in their home. With the support of Computerland and helped by high gross margins of up to 35%, Tallgrass grew very rapidly. Early in 1982, Allen added a tape backup product to the product line, another first for PCs. This first tape-backup product used out-sourced
Archive Corporation tape drive mechanisms and 3M cartridges. Later, Tallgrass opened a facility in Boulder, Co., to develop and manufacture smaller tape-backup drives. Allen's patented, all-digital
phase-locked loop circuit was used once again, this time in controlling the speed of the tape-drive's motor. The manufacturing cost of the disk and tape controllers was low because Allen's unorthodox controller design was shared by both disk and tape and, being 100% digital including the data-separator, it was easily reduced to a single LSI microchip. Gross revenue peaked in mid-1985 at an annualized rate of $70M and there were 400 employees at the start 1986. By this time significant competition had arrived and Tallgrass' sales had plateaued. To finance Volk's plan to revive sales growth with an enlarged marketing push, Allen accepted the overtures of venture capital. In mid-1986, Gateway Associates L.P. in St. Louis took the lead and brought in the major investor, Reimer and Koger Assoc., pension fund advisor for KPERS (the Kansas Public Employees Retirement System.) Sales continued to falter and profits sagged while management and investors disagreed over a course of action. In mid-1987 the investors forced Allen out and took control of the company. Volk left later the same year to go to
PrairieTek. Allen brought the investors a $4M buyout offer from
CMS Enhancements, a California competitor. A letter of intent was signed in July but allowed to expire in August. By November 1987 the investments reportedly totaled $7M, employment was down to 130, and annual sales revenue far below $40M. Tallgrass had 1992 sales of $9.3M and was "said to be profitable." In 1993 the investors sold what was left of Tallgrass to
Exabyte Corporation for $1.5M. By that time, KPERS investments in Tallgrass totaled over $14M. Not long after the acquisition, Exabyte sold the "Tallgrass Technologies" name to the former Tallgrass V.P. of International Sales, Jim Worrell, who then renamed his own import/export company using the Tallgrass name. Today his company has new ownership and a different charter but continues operating under the Tallgrass Technologies LLC name. ==References==