B&B Electronics PCRTC User Manual

Not Recommended for New Installations.

Please contact Technical Support for more information.

Stable Real Time Clock for PCs

Model PCRTC

Documentation Number PCRTC2095

This product

Designed and Manufactured

In Ottawa, Illinois

USA

of domestic and imported parts by

B&B Electronics Mfg. Co. Inc.

707 Dayton Road -- P.O. Box 1040 -- Ottawa, IL 61350

PH [phone] -- FAX [phone]

Internet:

http://www.bb-elec.com

[e-mail]

[e-mail]

 B&B Electronics March 1995

Documentation Number PCRTC2095 Manual Cover Page

B&B Electronics -- PO Box 1040 -- Ottawa, IL 61350

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Table of Contents

CHAPTER 1. GENERAL INFORMATION ....................................1

NTRODUCTION ........................................................................................1

I
P

ACKING LIST..........................................................................................1

S

PECIFICATIONS.......................................................................................1

CHAPTER 2. SETUP..........................................................................2

H

ARDWARE SETUP...................................................................................2

T

ABLE 1. ADDRESS SWITCH SETTINGS...................................................2

H

ARDWARE INSTALLATION .....................................................................3

S

OFTWARE SETUP....................................................................................3

CHAPTER 3. OPERATION...............................................................4

O

VERVIEW...............................................................................................4

U

SING THE DEVICE DRIVER.....................................................................4

C

OMMAND LINE OPTIONS........................................................................5

S

ETTING THE PCRTC TIME AND DATE ...................................................5

R

EPLACING THE BATTERY.......................................................................6

P

ROGRAMMING WITH THE PCRTC..........................................................6

Q

UICKBASIC PROGRAMMING EXAMPLE..............................................10

P

ASCAL PROGRAMMING EXAMPLE........................................................10

C P

ROGRAMMING EXAMPLE..................................................................11

CHAPTER 4. CALCULATING ERROR........................................12

PPM T

ERMINOLOGY..............................................................................12

O

SCILLATOR ERROR ..............................................................................12

APPENDIX A. HARDWARE I/O MAP..........................................14

Documentation Number PCRTC2095 Manual Table of Contents i

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Chapter 1. General Information

Introduction

The PCRTC is real time clock for PCs based on a highly
stable oscillator circuit. Using the software driver provided, the
PCRTC will update the DOS clock every minute, ensuring that all
applications have access to accurate time information.

With a simple function call, the PCRTC also reports battery
status and the time of the last power loss or computer reset.

Packing List

Examine the shipping carton and contents for physical
damage. The following items should be in the shipping carton:

1. PCRTC unit

2. One PCRTC 3.5” disk

3. This instruction manual
If any of these items are damaged or missing contact B&B
Electronics immediately.

Specifications

Setup

Address: Programmable with four position DIP switch
Interrupt: None required

Oscillator

Temperature Stability: < 5 ppm 0 - 50 °C
Calibration: < 1 ppm @ 23 °C (room temperature)
Aging: < 1 ppm

Power Requirements

35 mA @ 5VDC

Battery

Requires lithium AA battery 3-4V
Battery Life: approximately 10K hr. without host computer
powered.
Replacement batteries are available from B&B
Electronics, order as part number 3345.

Dimensions: 4.8” l x 3.0” h

Documentation Number PCRTC2095 Manual 1

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Chapter 2. Setup

Hardware Setup

The address switch on the PCRTC must be set to an
address which doesn’t conflict with other devices in the host
computer. The address settings are listed in Table 1, and are also
printed on the PCRTC card. The PCRTC is shipped from the factory
set for 200h. If you need to change this address, select one from the
table which will not conflict with another device in the host computer.
If the PCRTC does not operate properly, select a new address.
Remember to edit the file CONFIG.SYS to match the device driver
address to that used by the hardware. Appendix A contains a
hardware I/O address map for AT class PCs.

Table 1. Address Switch Settings

Hex

Address

200 0000
220 1000
240 0100
260 1100
280 0010

2A0 1010
2C0 0110
2E0 1110

300 0001

320 1001

340 0101

360 1101

380 0011
3A0 1011
3C0 0111
3E0 1111

Switch Settings

1234

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Hardware Installation

1. Shut the host computer power off.

2. Remove the computer cover.

3. Remove the expansion slot cover of an unused slot.

4. Handle the PCRTC only by its edges. Avoid touching any
conductors on the PCRTC. Install the PCRTC into the slot. Be
certain that the card is inserted completely into the slot.

5. Secure the card with the mounting screw from the slot cover.

The PCRTC is shipped with the oscillator halted to extend
battery life. To start the PCRTC, the card must be initialized. This
can be done using the command line option PCRTC /I found in
Chapter 3 of this manual or by the device driver. If you are using the
device driver, it will automatically initialize the PCRTC when it loads.
Upon initialization, a warning will appear stating that the oscillator
was halted and date and time information may be corrupt.

Software Setup

Place the 3.5” floppy disk in your “A” drive. Run the
installation program by typing “INSTALL” <Enter>. The files installed
to your hard drive include the PCRTC device driver, the shareware
program Timeset and three example files written in C, Pascal, and
QuickBASIC. These files demonstrate how to make function calls to
the PCRTC from within a program and are listed in Chapter 3. The
device driver will also be automatically installed in your
CONFIG.SYS file and set for address 200. If you require a different
address, remember to edit the CONFIG.SYS file to set the address
to match PCRTC hardware.

Documentation Number PCRTC2095 Manual 3

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Chapter 3. Operation

Overview

The most common application of the PCRTC is to simply
maintain the correct time on the host computer. Loading the device
driver in the CONFIG.SYS file will accomplish this function by
setting the DOS clock to the PCRTC clock time once every minute.
This allows the user and all applications access to the correct time
without any special commands or function calls.

The PCRTC has two additional features which may either
be incorporated using the provided “include file” and making
function calls within your program, or from the command line using
the PCRTC.EXE file. The first of these functions is battery status. By
checking the battery status you can take action on a low battery
before the time is corrupted. The second function is the time of last
power loss or reset. By checking this function, the time of the last
host computer power loss or system reset can be determined.

Using the Device Driver

In order for the PCRTC to automatically update the DOS
clock, the device driver PCRTCDD.SYS must be loaded from
CONFIG.SYS. This is done automatically by the installation
program. The following line will be added to the CONFIG.SYS file:

DEVICE = {path}PCRTCDD.SYS /A:{hex PCRTC address}

For example, if the file PCRTCDD.SYS is in the directory
C:\PCRTC, and the card address is set to 200h, use the following
line.

DEVICE = C:\PCRTC\PCRTCDD.SYS /A:200

If the address 200 is not compatible with your hardware, the
address parameter must be changed to match the address that was
selected for the hardware. After modifying the CONFIG.SYS file,
reboot the host computer. If the hardware and driver are installed
correctly, you should see the following message during bootup.

4 Documentation Number PCRTC2095 Manual

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