Asynchronous Floppy Drive Emulator - AFD

The Asynchronous Floppy Disc Unit (EVI-AFD) is an Electronic Visions, Inc. software product which provides a low cost replacement to MODCOMP's Model 4532 Asynchronous Floppy Disc (AFD) System. The PC-based processor system is connected as a peripheral device to a MODCOMP host computer via an RS-232C half-duplex asynchronous communication channel. EVI-AFD is supported as a data storage device with the MODCOMP Asynchronous Floppy Disc handler which combines asynchronous channel and floppy disc commands. The EVI-AFD software will operate in a rack mounted, desktop, mini-tower, or notebook PC/AT configuration.

The EVI-AFD offers single and dual density hardware sectoring, providing 15 and 26 sectors per track. All sectors have a fixed data length of 256 bytes. Commands and status are transferred with a frame size of eight bits with selectable parity. The AVI-AFD provides remote and local fill features for use with the host MODCOMP computer. The Format function is performed via an offline file format program. The Copy function is performed via Standard DOS file copy command. The Local Fill is performed via the F6 function key, Write Protect is toggled via the F7 function key for floppy 0 and the F8 function key for floppy 1. The Remote Fill can also be performed on Startup of the EVI-AFD software to allow auto-startup after power fail.


  PC/AT Controlled Diskette System one megabyte
  Multiple Asynchronous Channel Compatibility
  Standard MODCOMP 15 Selectable Baud Rates
  Selectable Parity Checking (Even, Odd, None)
  Half-Duplex Operation
  Selectable Density 295K bytes to 512K bytes
  MODCOMP II/IV/Classic Diagnostic Utility Load Device (Fillable/DAX Relocatable)
  Remote/Local Program Fill via Function keys
  Remote/Local Program Fill on startup
  Replaces obsolete hardware (AFD)
  Increases performance by 75% to 100%
  Utilizes PC/AT hardware technology for low cost and high reliability
  Supports MODCOMP hardware diagnostics
  All MODCOMP diagnostics loaded on hard drive for Local Program fill along with your OS and data files

SOFTWARE (Prerequisites)

  Standard MODCOMP® AFD Handler

HARDWARE (Prerequisites)

  MODCOMP System
  Asynchronous Controller
  Cabling to connect to EVI-AFD
  PC/AT system 286+ with hard drive, floppy, RS-232C Comm Port and optional CRT

Compatible Communications Controllers

1907-X   Universal Communications Subsystem with a 1931 RS-232C interface module. 1097-X = (1907, 1907A, 1907B)
1908-1   Integrated Communications Subsystem with model 1909-1 RS-232C interface.
4804   Quad Channel Interface Controller with model 4803-1 RS-232C interface.
4806   Asynchronous Terminal Controller with an RS-232C interface.
4807   Asynchronous Terminal Controller with an RS-232C interface.
4808   Asynchronous Modem Controller with an RS-232C interface.
4809   Octal Asynchronous Controller with an RS-232C interface.
4850   Multifunction Controller with a 4858-1 RS-232C Port Option interface.

Model Numbers and Descriptions

AFD-1   Software Only
AFD-2   Software with a PC-AT in a Low Profile 19" rack mounted enclosure. (Height: 4 ¼ in.)
AFD-3   Software with PC-AT in a Desktop or Minitower case.
AFD-4 Software with PC-AT Notebook configuration.

Physical Characteristics

 AFD-2 PC-AT in a Low Profile 19" rack mounted enclosure.
Height: 4 ¼ in.
Depth: 16 in.
Width: 19 in.
Weight: 15 lbs.

MODCOMP and CLASSIC are registered trademarks of Modular Computer Systems, Inc.
PC-AT may be a trademark of International Business Machines
EVI-AFD is a trademark of Electronic Visions, Inc.

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This page last modified on 08/19/97