Browse Prior Art Database

Intelligent PC Adapter Card for Devices

IP.com Disclosure Number: IPCOM000099163D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 3 page(s) / 89K

Publishing Venue

IBM

Related People

Lochner, DL: AUTHOR

Abstract

A circuit card is illustrated in Fig. 1 which an IBM PC, PC-XT, or PC-AT to control a device having Small Computer Systems Interface (SCSI). A memory technique allows several such cards to reside in a computer.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Intelligent PC Adapter Card for Devices

       A circuit card is illustrated in Fig. 1 which an IBM PC,
PC-XT, or PC-AT to control a device having Small Computer Systems
Interface (SCSI).  A memory technique allows several such cards to
reside in a computer.

      Major elements of the card, shown in the block diagram Fig. 1,
are the microprocessor 2 and its program memory a SCSI bus controller
chip 14, and a data memory 13. allow each of several cards in a PC
to control an SCSI device so that all devices can operate and
simultaneously under overall control by PC.

      Buffer 4 minimizes the load placed on signals of the PC 1,
forming a buffered PC bus 8.  Buffers 5 and 7 allow the PC or the
microprocessor 2 to have exclusive use local bus 6.  Buffer 10 allows
local bus 6 to access data 13, which is normally reserved for use by
SCSI 14.

      In a typical operating sequence, the PC disables a
microprocessor 2 and invokes access to program memory by setting
certain bits in the control logic 3.  The PC a program and/or control
parameters into program 12 for the desired operation, then returns
control to 2 by other bits in control logic 3.  The operating with
SCSI controller 14, causes device attached to the SCSI interface 15
to perform the operation.

      When an operation involves transfer of data (i.e., not or
status information) over the SCSI bus, that data contained in data
memory 13 which operates with SCSI 14.  Memory control circuit 11
provides address memory timing signals to data memory 13 in response
to from SCSI controller 14.

      The card includes timer 9 to allow the P...