Ferguson Big Board
The Big Board (1980) and Big Board II (1982) were
One version of the Big Board was used in the Xerox 820.
Hardware
The Big Board was sold as an unpopulated printed circuit board with sockets for integrated circuits, with documentation and options to purchase additional components[3] . The Big Board design was simple enough to build a system around that many people with no prior electronics experience were able to build and bring up a capable computer system of their own at a cost far less than that of a fully assembled system of the time. In this way, the Big Boards anticipated the
The design was also simple to modify for the sake of system expansion and enhancement. Many different modifications to increase the
It was possible to upgrade the memory to 256
The Big Board II (1982) incorporated many of the most popular upgrades for the original Big Board into its design. It also featured a small breadboard area that allowed for many simple upgrades to be performed without the addition of daughter boards.[7]
Software
The Big Board was designed primarily to run the CP/M operating system, version 2.2.[8] It came with a monitor program in ROM called PFM-80 which was the "software front panel" of the system. The source code listing of PFM was a feature of the first and second issues of Micro Cornucopia.[9] PFM featured many well-documented routines that could be employed in user code.[10]
The board featured 3 spare 2K ROM sockets that allowed for the addition of additional
Documentation
The Big Board came with a full set of
.Specifications
Big Board I
- CPUat 2.5 MHz.
- 64 KB dynamic RAMin 32 4116s or equivalent.
- An ASCII keyboard interface.
- A CRTinterface allowing a display of 24 lines by 80 characters.
- A SS/SD floppy disk interface allowing addition of up to four 8" Shugart Associates SA800 compatible 8" floppy disk drives.
- Two (optional) serial ports.
- A parallel Centronics compatible printer port.
- An optional real time clock.
- Board dimensions 8.5" (215 mm) by 13.75" (349.3 mm). (Compare to SA-800 disk drive: 9.5" x 14.5".)
Big Board II
- CPUat 4 MHz.
- 64 KB dynamic RAMin 8 4164s or equivalent.
- or for control of other SCSI devices.
- An ASCII keyboard interface.
- A CRTinterface allowing a display of 24 lines by 80 characters.
- A DS/DD floppy disk interface allowing addition of up to four 8" or 5.25" floppy disk drives.
- Two RS-232 serial ports via a Z80 SIO.
- A parallel Centronics compatible printer port via a Z80 PIO.
- An optional real time clock.
- Board dimensions 8.875" (225.4 mm) x 14.5" (368.3 mm)
- 6 ROM/EPROM sockets, including ability to program EPROMs in place.
Big Board Community
The success of the Big Board spawned Micro Cornucopia magazine.[12] Many Big Board kits included a subscription flyer for the magazine.
The magazine regularly featured user reports, hardware upgrade articles, and reviews of third party products. The magazine's publisher hosted the SOG (Semi Official Get-together) annually, where the magazine's readers would join staff and writers for
Third Party Products
The Xerox 820 computer was based on the Big Board; InfoWorld stated that its "considerable virtues ... lie mostly in its use of the Big Board's design".[14] Shugart Associates was a common source of floppy disk drives, as was Tandon Corporation.
Taylor Electric Company provided the "Better Board", including floppy disk drive interface enhancements, enhancements to PFM, and corrections to the original assembly and testing instructions bundled with the Big Board.
SWP Microcomputer Products of
Micro Cornucopia provided many products to enhance the Big Board computers, including speed upgrades, utility software and development tools both on ROM and on disk, and I/O enhancements.
AB Computer Products sold enclosures, monitors, and pre-punched I/O panels targeted at Big Board users.
D&W Associates of
Paradise Valley Electronics of
Several manufacturers, including JBW and Andy Bakkers sold SASI interface kits.
Kuzara Enterprises of
Several manufacturers provided real time clock upgrades as a CPU daughter board.
Andy Bakkers sold a 1 MB RAM Disk daughter board for Big Board II.
Kenmore Computer Technologies (from
References
- ^ J.B. Ferguson: The Bigboard: An Overview, 1980.
- ^ J.B. Ferguson: The Big Board II Assembly Manual, Cal-Tex Computers, 1982.
- ^ "The Big Board". BYTE (Advertisement). Vol. 7, no. 10. October 1982. p. 485.
- ^ Digital Research Computers: "Assembly Instructions", Big Board Documentation, 1980.
- ^ Hvizdak, Gary (February 1982). "3.5MHz (Easiest Mod of All)". Micro Cornucopia. No. 4. p. 9.
- ^ Boehm, Art (June 1983). "256K in Detail-Part I". Micro Cornucopia. No. 12. p. 4.
- ^ J.B. Ferguson: Big Board II Assembly Manual, Cal-Tex Computers, 1982.
- ^ J.B. Ferguson: The Bigboard: An Overview, 1980.
- ^ Retzlaff, Don (July 1981). "PFM-80 Monitor". Micro Cornucopia. No. 1. p. 9.
- ^ Russel Smith: PFM-80 Users Manual, 1980.
- ^ DeVoe, Rob (June 1982). "A Self-Loading ROM". Micro Cornucopia. No. 6. p. 10.
- ^ Thompson, David (June 1982). "Spare a Dime?". Micro Cornucopia. No. 6. p. 2.
- ^ Thompson, J.D. (June 1983). "All Wet!". Micro Cornucopia. No. 12. p. 2-30.
- ^ Meyer, Edwin W. (14 June 1982). "The Xerox 820, a CP/M-operated system from Xerox". InfoWorld. Vol. 4, no. 23. pp. 101–104. Retrieved 2019-03-30.