Eagle Computer



Eagle Computer of Los Gatos, California, was an early microcomputer manufacturing company. Spun off from Audio-Visual Laboratories (AVL), it first sold a line of popular CP/M computers which were highly praised in the computer magazines of the day. After the IBM PC was launched, Eagle produced the Eagle 1600 series, which ran MS-DOS but were not true clones. When it became evident that the buying public wanted actual clones of the IBM PC, even if a non-clone had better features, Eagle responded with a line of clones, including a portable. The Eagle PCs were always rated highly in computer magazines.

The AVL Eagle I and II had audio-visual connectors on the back. As a separate company, Eagle sold the Eagle I, II, III, IV, and V computer models, and external SCSI/SASI hard-disk boxes called the File 10 and the File 40.The first Eagle computers were produced by Audio Visual Labs (AVL), a company founded by Chuck Kappenman in New Jersey in the early 1970s to produce proprietary large-format multi-image equipment. Kappenman introduced the world’s first microprocessor-controlled multi-image programming computers, the ShowPro III and V, which were dedicated controllers. In 1980, AVL introduced the first non-dedicated controller, the Eagle. This first Eagle computer used a 16 kHz processor and had a 5-inch disk drive for online storage. The Eagle ran PROCALL (PROgrammable Computer Audio-visual Language Library) software for writing cues to control up to 30 Ektagraphic projectors, five 16 mm film projectors and 20 auxiliary control points. Digital control data was sourced via an RCA or XLR-type audio connector at the rear of the unit. AVL’s proprietary “ClockTrak” (a biphase digital timecode similar to, but incompatible with SMPTE timecode) was sourced from the control channel of a multitrack analog audio tape deck. The timed list of events in the Eagle was synchronized to the ClockTrak. Later versions of PROCALL included the option of using SMPTE timecode. Most programmers abandoned ClockTrak for SMPTE, as more multi-image programs began to incorporate video. Two separate digital data streams were output from the Eagle, also via RCA or XLR-type audio connectors. These telemetry streams, called “PosiTrak”, each controlled up to five external slide projector control devices also manufactured by AVL, known as “Doves”. The Dove units received biphase data from the Eagle via audio cables, and interpreted the Eagle’s data streams to control as many as three Kodak Ektagraphic projectors (for large screens, compatible Xenon-lamped projectors) and two dry-closure contacts per Dove unit. AVL also made the Raven, a device similar to the Dove, for comprehensive control of a single 16 mm film projector, as well as numerous other external control devices for lighting, sound, video projectors and sources, etc.AVL Eagles and associated products, when properly set up and powered, were extremely reliable. During the 1970s through the early 1990s, when the products of its competitors were not as reliable nor readily available, AVL became the industry standard for multi-image control equipment. However, the development of large-screen electronic media and HDTV ushered out the era of film-based multi-image productions.

All CP/M Eagles had the same basic design, except for the storage devices. The exception to this was a portable model, in which the keyboard formed a removable lid that could be snapped to the main unit for traveling. An attractive off-white case held the entire computer. The top section held a green monochrome monitor on the left, and one or two full-height storage devices, stacked one above the other, on the right. An anti-glare screen was held in place against the front of the monitor, and the front of the top section shut, by a black plastic bezel. This bezel snapped into place. The back of this section held a fan right behind the drive enclosure, and a silver label behind the monitor with the company logo and address, the model number, serial number, voltage, frequency, and current. The bottom section projected forward and had the keyboard in its top, and the system logo. Inside this “clamshell” was the main circuit board, connected to the monitor, drives, keyboard and ports by cables. Underneath the main board and connected to it by cables was a Xebec hard-disk controller card. On the back of the clamshell was the reset button, two RS-232 serial ports labeled “Serial A” and “Serial B”, a Centronics parallel port labeled “Parallel A”, a SASI port labeled “Parallel B”, the brightness knob for the monitor, and the on/off switch. The keyboard was well-designed. The keys were black with white lettering. Besides a full typewriter keyboard, there was a complete ten-key number pad on the right, uncommon at that time. Labels on the front of the number keys of the typewriter keyboard, and all the keys of the number pad, denoted what function those keys performed in the command mode of the bundled Spellbinder software. The CPU of the whole line was a 4-MHz Zilog Z80A, the standard microprocessor of the day. Memory was 64K, which was all the RAM that the standard CP/M 2.2 operating system could address with an 8-bit chip.

Also available were external hard-disk units called the File 10 and File 40. These were metal Corvus boxes with a fan and power switch on the back. Inside a File 10 was the same hard disk as an Eagle IV had, the same Eagle SASI card, and a power supply. The File 40 had the same 32 MB hard disk as an Eagle V. To upgrade an Eagle III, for instance, the user could buy a File 40, connect it to the “Parallel B” port on the back of the Eagle with the ribbon cable that came with it, turn on the File 40, and turn on the Eagle. If a File 10 or File 40 was attached and turned on when an Eagle I, II, or III was turned on, the computer booted from the hard disk in the external box, even if a bootable floppy disk was in a floppy-disk drive. An Eagle III with a File 10 attached had the same hard-disk storage as an Eagle IV, but two floppy-disk drives instead of one. Similarly, with a File 40 attached, it was functionally the same as an Eagle V with an extra floppy-disk drive.



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