RadiSys EPC-31 Application guide

EPC-31/32
Hardware Reference
RadiSys Corporation
15025 S.W. Koll Parkway
Beaverton OR 97006
[phone]
FAX: [phone]
EPC and RadiSys are registered trademarks of RadiSys Corporation. OS/2, IBM, and PC/AT are
trademarks of International Business Machines Corporation. Microsoft Windows and MS-DOS are
registered trademarks of Microsoft Corporation. Intel and Intel486 SL are trademarks of Intel Corporation.
April 1994
Copyright © 1994, 1995 by RadiSys Corporation
All rights reserved.
Hardware Warranty
RadiSys Corporation ("RadiSys") warrants the EPC system and component modules to the original
purchaser for two years from the product's shipping date. If an EPC product fails to operate in compliance
with its specification during this period, RadiSys will, at its option, repair or replace the product at no
charge. The customer is, however, responsible for shipping the product; RadiSys assumes no responsibility
for the product until it is received. This warranty does not cover repair of products that have been damaged
by abuse, accident, disaster, misuse, or incorrect installation.
RadiSys' limited warranty covers products only as delivered. User modification, such as the addition of
memory airays or other devices, may void the warranty, and if the product is damaged during installation of
the modifications, this warranty does not cover repair or replacement.
This warranty in no way warrants suitability of the product for any specific application.
JN NO EVENT WILL RADISYS BE LIABLE FOR ANY DAMAGES, INCLUDING LOST PROFITS,
LOST SAVINGS, OR OTHER INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF
THE USE OR INABILITY TO USE THE PRODUCT EVEN IF RADISYS HAS BEEN ADVISED OF
THE POSSIBILITY OF SUCH DAMAGES, OR FOR ANY CLAIM BY ANY PARTY OTHER THAN
THE PURCHASER.
THE ABOVE WARRANTY IS IN LIEU OF ANY AND ALL OTHER WARRANTIES, EXPRESSED
OR IMPLIED OR STATUTORY, INCLUDING THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE OR USE, TITLE AND NON-INFRINGEMENT. Repair or
replacement as provided above shall be the Purchaser's sole and exclusive remedy and RadiSys' exclusive
liability for any breach of warranty.
NOTES
Table of Contents
1. Product Description 1
Specifications 2
2. Installation and Configuration 3
Installation 3
Power-On Screen Display 4
BIOS Setup Screen 5
Date and Time 6
Configuration Errors 7
Diskette Drive 7

Fixed Disk Drive
7
Cache
7
Quick Boot
7
Update BIOS
8
COM1/COM2
8
LPT1
8
Floppy
8
IDE
8
Fixed Disk Menu
8
User-Definable Drive Types
9
Theory of Operation
11
Processor and Coprocessor
12
Memory
13
Memory Expansion
13
ROM and ROM Shadowing
14
Battery
14
Speaker
15
Miscellaneous Connector
16
Resetting the EPC
17
Watchdog timer
18
Power and Cooling Requirements
19
Cooling
19
Fuse
19
SVGA Video Controller
20
Flat Panel Support
20
Flash Disk Subsystem
21
EPC-31/32 Utilities Diskette Contents
22
Onboard Flash Utility Installation
22
Formatting Program
22
XFORMAT Error Messages
26
Flash BIOS Updating
28
Peripheral Interfaces
31
ISA bus
32
Connectors
35
Overview
35
IDE Hard Disk Drive Controller
36
Floppy Disk Drive Controller
37
COM2/LPT1 Connector
38
Miscellaneous Connector
39
Flat Panel Display Connector
40
Power Connector
41
AT/ISA Bus Connector Pin-out
42
SVGA Connector
44
Serial & Parallel Ports
45
Keyboard
45
Troubleshooting & Error Messages
47
Troubleshooting
47
Common Error Messages
48
Upgrades
55
Memory
55
Support and Service
57
In North America
57
Technical Support
57
Bulletin Board
57
Repair Services
58
Warranty Repairs
58

Non-Warranty Services 58
Arranging Service 59
Other Countries 60
Appendix A: Mechanical Dimensions 61
Appendix B: Chip Set and I/O Map 63
Memory Map 63
I/O Address Maps 64
Appendix C: AT Bus Connector Signals 75
AT Bus Expansion Connector Signals 75
Appendix D: Video Modes and Supported Panels 81
Index 14
Figures
Figure 1. POST Display 5
Figure 2. Main Setup Screen 6
Figure 3. Fixed Disk Menu Screen 9
Figure 4. Replacing the Battery 14
Figure 5. EPC-31/32 Mechanical Dimensions 61
Figure 6 . Mounting Hole Dimensions 62
Tables
Table 1. EPC-31/32 Environmental and Electrical Specifications 2
Table 2. Fixed Disk Conversion Values 10
Table 3. SIMM Organization 13
Table 4. EPC-31/32 Terminations 33
Table 5. IDE Hard Disk Drive Connector Pin-out 36
Table 6 . Floppy Disk Drive Pin-out 37
Table 7. COM2/LPT1 Pin-out 38
Table 8 . Miscellaneous Connector Pin-out 39
Table 9. Flat Panel Display Connector Pin-out 40
Table 10. Power Connector Pin-out 41
Table 11. AT/ISA Bus Connector Pin-out 42
Table 12. AT Bus Pin-out 43
Table 13. SVGA Connector Pin-out 44
Table 14. DB-9 Pin-out 45
Table 15. Keyboard Connector Pin-out 45
Table 16. Memory Map 63
Table 17. First ( 8 -bit) DMA Controller Map 64
Table 18. First Interrupt Controller Map 65
Table 19. Counter-Timer Functions Map 65
Table 20. Keyboard Port Map 65
Table 21. Time-of-Day Clock Map 66
Table 22. DMA Page Registers Map 67
Table 23. Miscellaneous Map 67
Table 24. Second Interrupt Controller Map 67
Table 25. Second (16-bit) DMA Controller Map 68
Table 26. VL82C486 Controller Map 68
Table 27. Coprocessor Interface Map 69
Table 28. VL82C486 Controller Map 69
Table 29. COM2 Serial I/O Port Map 70
Table 30. Parallel I/O (LPTl) Port Map 70
Table 31. Super VGA Controller Map 72
Table 32. COM1 Port Map 73
Table 3 3. Floppy Disk Drive Controller Map 73
Table 34. IDE Hard Disk Drive Controller Map 74
Table 35. Flash Disk Subsystem Map 74
Table 36. Watchdog Timer Map 74

1. Product Description
The EPC-31/32 are PC/AT compatible single board computers. The EPC-31 uses the 25 MHz Intel486 SX
processor, and the EPC-32 uses the 33 MHz Intel486 DX processor. Where practical, this manual refers to
the EPC-31/32 when discussing characteristics similar to both modules.
The EPC-31/32 has been designed to meet stringent safety and low EMI standards (UL-1950). All
mounting bracket ports have filter networks for reduced EMI and increased ESD protection
A
Many of the connectors on the EPC-31/32 provide power through different pins. Connecting the
wrong cable or reversing the cable can damage the EPC-31/32 and may damage the device being
connected. Use extreme caution when preparing to connect cables to this product. Refer to the
diagram in Appendix A for complete connector labeling.
The EPC-31/32 processor module contains the following:
A 25 MHz Intel486 SX or 33 MHz Intel486 DX processor
Options for 0 and 1 MBytes of on-board base memory
One 72-pin SIMM socket providing up to 16 MBytes of DRAM
Full ISA bus compatibility, including DMA and interrupt controllers
2 RS-232 COM ports — one 9-pin connector and one header connector
LPT1 parallel port available through a header connector
PC-compatible floppy drive controller accessed through a header connector
IDE hard drive interface for 2.5" drives, using a 44-pin header
PC/PS-2 keyboard interface via a 6-pin mini-DIN connector
Time-of-day clock with user-replaceable battery
Field-upgradable Award BIOS in flash memory
Watchdog timer
Optional:
Super VGA controller/flat panel display controller, with 512 Kbytes memory
1 or 2 MBytes on-board Flash memory configurable as a DOS bootable disk
Specifications
The following table lists the environmental and electrical specifications of the
EPC-31/32.
Environmental
Temperature
storage
Humidity
storage
0 - 60°C derated 2°C per 1000 ft (300 m) over 6600 ft (2000m)
operating
-40 to 85°C
operating 5 - 95% (non condensing)
5 - 95% (non condensing)
Altitude operating 0 - 10,000 ft (3000 m)
storage 0 - 40,000 ft (12,000 m)
Vibration operating 2.5 g acceleration over 5-300 Hz sine wave (P-P), 1 oct/min sine sweep
storage 5 g acceleration over 5-300 Hz sine wave (P-P), 1 oct/min sine sweep
Shock operating 30 g, 11 ms duration, half-sine shock pulse
storage 50 g, 11 ms duration, half-sine shock pulse
Electrical
Current typical +5V @ 1 0A 486SX 25MHz
+5V @ 1.1A 486DX 33MHz
+12V @ 50mA for writing to flash BIOS or on-board flash memory
Table 1. EPC-31/32 Environmental and Electrical Specifications.
* Upper temperature limit degrades 2 C per 1,000 ft. elevation. Maximum
elevation 10,000 ft.

Vibration and shock specifications assume the EPC-31/32 is mounted as a single board computer, and is not
installed in a standard ISA chassis.
The EPC-31/32 is capable of driving a four-slot ISA backplane.
See Appendix A for mechanical dimensions.

22. Installation and Configuration
Before installing the EPC-31/32, unpack and inspect it for shipping damage.
do not remove the module from its anti-static bag unless you are in a static-free
environment, the
epc-31/32, like most other electronic devices, is susceptible to esd damage, esd damage is
not always immediately obvious, in that it can cause a partial breakdown in
semiconductor devices that might not immediately result in a failure.
4
ensure that the installation process as described herein is also performed in a static-
free environment.
Installation
The EPC-31/32 can be installed in an ISA bus passive backplane or mounted using screw holes. If ISA bus
connection is required when mounted using the screw holes, use the ISA bus header pins.
To mount the EPC-31/32 to a non-conductive surface using the four screw holes, be sure to select a location
where you have access to all available header pins and connectors. Mounting holes on the EPC-31/32 are
1/8" (0.125") in diameter, or 3.175 mm. The spacing of the mounting holes is 6.1" (154.9 mm) by 3.55"
(90.2 mm). Refer to Appendix A for a depiction of the EPC-31/32 mechanical dimensions.
It may be necessary to remove the PC mounting bracket from the EPC-31/32 before mounting flat on a
surface.
Cooling requirements are minimal. In most cases a cooling fan is not necessary. Refer to the environmental
specifications in Chapter 1 for temperature information.
Insertion of the EPC-31/32 into an ISA bus chassis or a passive backplane is straightforward. Remove a
blank panel from the chassis and insert the EPC-31/32 into the backplane card connector. Firmly press the
EPC-31/32 down to ensure that the module is properly seated in the backplane.
make sure system power is off. the epc-31/32 cannot be inserted into or removed from
a live system.
ih , , ,
when inserting the epc-31/32, avoid touching the circuit board, and make sure the
environment is static-free.
insert it with adequate continuous force rather than tapping or hammering on it.
Power-On Screen Display
During the setup and configuration of the EPC-31/32, a monitor and keyboard are required.
Whenever a hardware reset of the EPC occurs, the system performs a POST. If not set for "quick boot," the
POST displays information showing the status of the BIOS self-test. If everything proceeds normally, the
screen image displays approximately as shown below.
486 Modular BIOS V3.0Sabd.
Copyright (e) 1964-90 Award Software Inc.
Copyright 1993 RadiSys Corporation Flash BIOS V3.0S
TESTING INTERRUPT CONTROLLER #1 .OK
TESTING INTERRUPT CONTROLLER #2 .OK
TESTING CMOS BATTERY.OK
TESTING CMOS CHECKSUM.OK
SIZING SYSTEM MEMORY. 640K FOUND
TESTING SYSTEM MEMORY. 640K OK
CHECKING UNEXPECTED INTERRUPTS AND STUCK NMI .DK
TESTING PROTECTED MODE.OK
SIZING EXPANSION MEMORY. 3328R FOUND
TESTING MEMORY IN PROTECTED MODE . 4352K FOUND
TESTING ONBOARD SERIAL PORT #1.OK
TESTING ONBOARD SERIAL PORT #2.OK
TESTING ONBOARD PARALLEL PORT.OK
RadiSys EPC Setup Program
Figure 1. POST Display.
If errors occur during the power-on self-test, the BIOS displays the error on the appropriate line of the
screen display and attempts to continue. For instance, if a failure is discovered in COM1, the BIOS disables
COM1, displays the error on the line "TESTING ONBOARD SERIAL PORT #1." and then continues as
if the error did not occur. It is important to watch the POST display to verify that no errors occur.

If error messages are displayed during or after the POST display, see chapter 5, Troubleshooting & Error
Messages.
BIOS Setup Screen
The EPC-31/32 BIOS contains a setup function to display and alter the system configuration. This
configuration information is maintained in the EPC-31/32’s battery-backed CMOS RAM and is used by the
BIOS to initialize the EPC-31/32.
The setup function can be invoked any time after the POST completes and first clears the screen.
Simultaneously press the CTRL+ALT+ESC keys. This may be done during system operation in most, but
not all circumstances. Some programs that take control of the keyboard at a low level, such as Microsoft
Windows, cause this key sequence to be interpreted differently, or not at all. It should always work,
however, when the DOS operating system prompt is shown on the screen. The main setup screen displays
similar to the following:
RadiSys EPC-31 CMOS Setup, Flash System BIOS V3.05
486SX, 4 MBytes memory, 487SX not present
Date (mm/dd/yy)
Time (hh:mm:ss)
Configuration Errors
Diskette Drive A
Diskette Drive B
Fixed Disk Drive C
Fixed Disk Drive D
01/12/90
09:34:56
Halt on all errors
1.4M 3.5 inch
None
AT
None
Cache
Enabled
Quick Boot
Disabled
Update BIOS
Disabled
Coml:
Enabled
F2 = Fixed Disk Menu
Coiu2:
Enabled
F10 = Save CMOS
LPT1:
Enabled
ESC= Exit without saving
Floppy
Enabled
move between items
IDE
Enabled
select values
Figure 2. Main Setup Screen.
Use the up and down arrow keys to move the cursor from field to field. For most fields, once the cursor is
positioned at the field, pressing the left and right cursor (arrow) keys will scroll through the available
choices. Once the screen has been changed to appear as you desire, press the FI0 function key to save the
changes in battery-backed CMOS RAM. Then press the F5 function key to confirm the changes and reboot,
FI to confirm changes but not reboot or ESC to ignore any changes and exit. Each field is explained below.
Date and Time
These values are changed by moving to them and typing in the format shown.
Configuration Errors
This field provides several choices about the situations under which the BIOS should wait for user input if a
configuration error is found. The selections are:
1) Halt on all errors
2) Ignore all errors
3) Ignore keyboard errors (allows operation without a keyboard)
4) Ignore disk errors
5) Ignore keyboard and disk errors
Diskette Drive
This field gives you several choices about the type of floppy disk drives installed as the A and B drives.
Toggle the entry to match the type of diskette drive(s) attached. If no floppy drive is attached, select NONE
for each diskette drive field.
Fixed Disk Drive
This display-only field shows the type of disk selected from the fixed disk menu. Possible values are None,
AT and FLASH. To see the detailed characteristics of the device or to change the device, use the F2
function key to go to the fixed disk menu. See the section Fixed Disk Mem. This applies only to IDE disk
drives attached directly to the EPC-31/32 and onboard flash, and does not apply to any external drives
connected to other disk controllers.
Cache

Toggling this field enables or disables the cache. The default is to enable the cache.
Quick Boot
This field enables or disables the quick boot option. When quick boot is disabled, a hard boot causes the
system to display the results of the POST and runs the memory test. When quick boot is enabled, the system
runs the POST except the memory test and displays "Quick boot enabled: disable through Setup screen to
view."
Update BIOS
Toggling this field enables or disables the BIOS serial update feature. When disabled, the system boots
normally. When enabled, the system searches for 10 seconds on COM1 for clear-to-send (CTS)
synchronization from an external host. The external host must be currently running the NEWBIOS.EXE
program (refer to Flash BIOS updating in Chapter 3). If the system can synchronize with the host, the BIOS
on the EPC-31 is reflashed and updated. Note that the field must be disabled on the next pass through the
boot process. If the system cannot synchronize, after ten seconds the boot continues.
COM1/COM2
Toggling these fields enables or disables the built-in COM1 and COM2 ports.
LPT1
Toggling this field enables or disables the built-in LPT1 parallel port.
Floppy
Toggling this field enables or disables the built-in floppy controller. If using an external floppy controller,
disable the EPC-31/32 floppy controller.
IDE
Toggling this field enables or disables the built-in IDE hard drive interface. If using an external IDE
controller, disable the EPC-31/32 IDE controller.
Fixed Disk Menu
The Fixed Disk Menu is used to define the type of hard disk(s) installed in the system using the onboard IDE
disk controller or Flash. Enter the fixed disk menu screen by pressing the F2 function key from the main
setup screen. The Fixed Disk Menu screen is similar to the following:
RadiSys EPC-31 Fixed Disk Menu, Flash System BIOS V3.05
486SX, 4 MBytes memory, 487SX present
Fixed Disk Drive C: AT
Type 17 41 MBytes: 977 Cyls, 5 Heads, 17 Sectors
Landing Zone: 977 Precompensation: 300
Fixed Disk Drive D: None
F10 - Save and return
ESC - Return without saving
move between items
select values
Figure 3. Fixed Disk Menu Screen.
Use the up and down cursor keys () to move between items. Use the left and right cursor keys ( ) to scroll
through the available choices for each item.
Disk type AT denotes IDE-compatible drives. You can scroll through a set of numbered types; the physical
configuration is displayed for each. Scroll through the numeric drive types to find the one matching the
characteristics of the hard drive installed. Refer to the reference manual that accompanied the hard drive.
Choose disk type Onboard Flash if you are using the onboard flash memory. This flash memory can be
made the boot device by making onboard Flash the drive C: type. However, if Drive C: is onboard Flash,
Drive D: must be set to None. You cannot set the onboard Flash as the C: drive AND use an external disk
controller (IDE or SCSI) to provide a D: drive.
User-Definable Drive Types
If the correct AT disk type is not listed, the EPC-31/32 provides user-editable drive types 48 and 49. Select
either of these drive types. Use the TAB key ()or the left and right cursor keys ( ) to move to the next (or
previous) field. Note that the default settings for MBytes, Cylinders, Heads, and Sectors is 1. MBytes is a
display-only field calculated by the BIOS. Move the cursor to each field (Cyls, Heads, and Sectors) and
type the value for that field.
The BIOS allows use of the following maximum values:
Cylinders 1023 Heads 16 Sectors 63

The hard disk you are using may have parameters larger than the allowable maximum. If the number of
cylinders for your drive is greater than the maximum allowable number, you may have to use 1023 cylinders
which will limit the usable size of the drive. However, most IDE drives support universal translation mode.
If the drive you are using supports this mode and the actual parameters are greater than the allowable
maximum, divide the actual number of cylinders by 2 and multiply the actual number of heads by 2. That
is, each sector is addressed as an absolute sequential sector number. Since the drive converts the sector data
to an absolute number, these "false" cylinder and head numbers will still allow the full capacity of the drive
to be used. The following example shows how this is done.
Actual parameters Conversion factor Numbers to Use
Cylinders 1350 divide by 2 675
Heads 5 multiply by 2 10
Sectors 32 (none) 32
Total Sectors 216,000 216,000
Table 2. Fixed Disk Conversion Values.
After the fixed disk(s) have been configured, press F10 to save the data or ESC to ignore the changes. In
either case you return to the main setup screen. Follow the instructions on the screen to save and exit or
ignore changes and exit.

3. Theory of Operation
This chapter contains information about the following:
EPC-31/32 processor and coprocessor
EPC-31/32 memory map and memory expansion
ROM shadowing
Battery
Speaker
Miscellaneous connector
Resetting the EPC-31/32
Watchdog timer
Power and cooling requirements
Fuse
SVGA video controller
Flat panel support
Hash disk sub system
Utilities software diskette
COM and Parallel ports
AT/ISA bus
Processor and Coprocessor
Hie EPC-31 uses the 25 MHz Intel466 SX CPU, which does not contain an integrated math coprocessor.
Hie EPC-32 uses the Intel486 DX CPU, which runs at 33 MHz and contains an integrated math
coprocessor. Note that this is not a socketed part, and therefore is not field-upgradable.
The board design uses the VLSI technology VL82C486 AT chip set to interface the 80486 to the AT-bus.
The VL82C486 and its companion chip, the VL82C114, contain the following standard PC peripheral
functions: two 82C37A DMA controllers, two 82C59A interrupt controllers, an 82C54 timer/counter, a
74LS612 memory mapper, 486 to AT bus data, address, and control strobe buffers, a real time clock with
128 bytes of battery backed SRAM, a PC compatible keyboard controller, a DRAM controller, and several
miscellaneous functions.
Besides the standard AT peripheral registers, the VL82C486 contains 28 control registers that allow
program control of DRAM access timing, memory mapping, and several other functions. These registers
can only be accessed indirectly by writing an indirect register address to OxEC, and following this write with
an I/O access to OxED to perform the actual read/write of the register desired.
Most of these functions are only set once by the BIOS at reset time. The BIOS or application software may
disable access to these registers by performing an I/O write to 0xF9. Re-enabling access to the registers is
accomplished by performing a dummy I/O write to OxFB.
Memory
Hie EPC-31/32 can have an on-boaid base memory configuration of 0 or 1 Mbyte. When present, the base
memory is soldered on the motherboard. This base memory can be expanded using a 4,8 or 16 MByte
SIMM module.
Additional RAM is supported via the ISA-bus (up to a maximum of 16 MBytes total).
After power on reset, the BIOS will find and size memory present in the system. The DRAM timing (in
CPU clocks) in a 25MHz EPC-31 system is set to enable the 80486 bus to achieve 4-2-2-2 timing on burst
reads that "hit" a previously activated page. The 33 MHz EPC-32 system is set to enable the 80486 bus to
achieve 4-3-3-3 timing.
The DRAM controller is set to map 80486 addresses in the region from 0x000A0000 to OxOOOEFFFF to the
AT-bus (with the exception of OxOOOCOOOO - 0x000C7FFF, the video BIOS, which will be shadowed into
main DRAM). Memory references to these addresses will not be cacheable by the 80486SX. Memory
accesses beyond the installed DRAM are automatically sent to the AT bus. Accesses above 128MB wrap
back around to address 0.
Memory Expansion
A single 72-pin SIMM socket is provided for memory expansion. SIMM memory occupies bank 2. A

standard SIMM module is used for memory expansion, or if no base memory is present, as primary RAM.
Modules must meet the following criteria:
- fast page mode
- 72-pin
- 80 nanosecond DRAM or faster
Recommended part numbers for SIMMs are discussed in Chapter 6, Upgrades: The table below specifies
the various SIMM modules used:
SIMM Memory SIMM organization
4 MB 1 sided 1 MB x 36-bit
8 MB 2 sided 2 MB x 36-bit
16 MB 2 sided 4 MB x 36-bit
Table 3. SIMM Organization.
ROM and ROM Shadowing
The EPC 31/32 contains a flash BIOS device that is mapped into the last 128 Kbytes of the processor's
address space. The flash device contains the PC BIOS, VGA BIOS, POST functions, and the setup
screen program.
For best possible performance, the BIOS initialization software copies the system BIOS into DRAM
(called shadowing) at addresses OFOOOO-OFFFFF (also called the *F* page)- After copying into this area,
the BIOS write-protects it. Subsequent writes to this area complete successfully but do not alter the data.
The system can only support one VGA controller. The BIOS also searches segment C800 through EFFFh
for the existence of additional BIOS EPROMs. Additional BIOS extensions are not shadowed.
Battery
The battery powers the CMOS RAM and Time of Day clock when system power is not present. At 60°C,
the battery should have a shelf life of over four years. In a system that is powered on much of the time
and where the ambient power-off temperature is less than 60 °C, the battery is estimated to have a life of 3
years.
Hie battery supplied with the EPC-31/32 is a 23mm. 3V lithium "coin" battery or equivalent (e.g.
Panasonic BR200 or equivalent). Refer to Appendix A for mechanical dimensions and battery location.
Should the battery fail, you may obtain and install a replacement. Figure 4 below illustrates how to
change the battery.
1. Gently lift
retaining clip
2. Slide battery
in/out in line with
the direction of the
retaining clip.
Figure 4. Replacing the Battery.
Replacing the battery is a simple task. However, removing the battery will invalidate the CMOS setup
parameters. It is recommended that all setup parameters be written down while the battery is still good.
Speaker
A very small speaker (0.5 in., or 12.7 mm) is installed on the EPC-31/32 and connected to the standard PC
"beep” generation circuit. In high-noise conditions, a larger external speaker may be required. When used,
an external speaker is driven by a 5V peak-to-peak square-wave signal, with current limiting resistors.
Either a piezoelectric speaker or an electromagnetic speaker may be used externally.
The EPC-31/32 contains a miscellaneous function connector to provide access to the external speaker

circuit. Hie 14-pin 100-mil center header is explained further in Chapter 4, Connectors
Miscellaneous Connector
Hie Miscellaneous Connector CN4 contains a variety of signals used by standard PCs.
HDD access LED - a signal is provided for the user to connect an external LED to to indicate hard disk
drive access. An external current-limiting resistor is not required; current will be limited by a 330 ohm
resistor to VCC.
Power on LED - a signal is provided for the user to connect an external LED to indicate that power is
applied to the system. An external current-limiting resistor is not required; current will be limited by a
330 ohm resistor to VCC.
Reset switch - an input is provided for the user to connect an external, SPST-NO switch to provide a reset
input to the system. This signal may also be driven with an open-collector TTL signal.
Key switch input - an input is provided to port P17 of the keyboard controller. This is normally
connected to a keylock switch to disable the keyboard in the PC/AT system. This input has an internal
pullup resistor to VCC.
Battery input - an input is provided to allow the connection of an external battery, to provide a voltage
supply for the real-time clock and CMOS RAM. This connection is protected by a diode, and cannot
source current from the on-board battery or VCC. Hie voltage supplied should in no case be greater than
S.5 volts.
Resetting the EPC
There are a number of ways to reset (reboot) the EPC.
Power-off, Power-on
This causes the entire system to reset. The system will run the power-on self-tests and reboot the
operating system.
External Reset Input
The external reset input causes the EPC-31/32 to perform a hardware reset. The system will run
the power-on self-tests and reboot the operating system.
Setup Screen
Pressing F10 and then F5 to save changes and reboot causes a processor shutdown. The system
will run the POST and reboot the operating system. It does not cause an AT reset.
CTRL+ALT+DEL
This keyboard sequence is called a "warm boot." The EPC does not reinitialize all of the
processor's hardware. The power-on self-test does not run. However, the operating system will
be reloaded. This type of reset typically only works under DOS.
Watchdog timer
This causes the entire system to reset. Hie system will run the power-on self-tests and reboot the
operating system. See below for more details.
Additional abnormal conditions that cause a reset
Low Vcc
Watchdog timer
A watchdog timer function is included to provide a RESET signal to the CPU and ISA bus system in the
event that software loses control of the system.
A register is present that enables or disables the watchdog timer function, and allows the selection of two
different time-outs. The register returns the value FF when read. It is defined as follows:
Watchdog Register 0x384:
D7 - D2 D1 DO
Unused Timeout length Watchdog enable
If the timeout length bit is set to 0, the watchdog timeout will be set to 100 mS. If the bit is set to 1, a 1.6
second timeout will be selected. These times are approximate, +/- 20%, as they are determined by a
passive RC circuit attached to a Maxim MAX696 reset generator IC.
If the watchdog enable bit (bit 0) is set to 0, the watchdog function is disabled. If the bit is set to 1,
watchdog time-outs will be enabled, and the system will be reset at the end of the timeout period, unless
the watchdog is reset by a read or write of the watchdog register.

Either a read or write operation to this register will reset the watchdog timer.
Upon system reset, this register will be initialized to 00.
Power and Cooling Requirements
In most applications, the EPC-31/32 will operate on 5V DC power only. The voltage required is between
4.75 and 5.25 volts. +12V must be supplied via the ISA-bus (or ISA-bus headers) to erase or program the
FLASH devices, including the BIOS.
+5V may be supplied either via the ISA-bus edge connector, the ISA-bus header, or the power header
(CN3). Care must be taken that the maximum current ratings of the connectors are not exceeded.
Cooling
The EPC-31/32 meets the standard RadiSys environmental specifications. This includes operation at
temperatures from 0 to +60 C. The EPC-31/32 meets this specification in still air, with no forced cooling
required.
Fuse
The EPC-31/32 has a user-replaceable fuse protecting the floppy disk circuit. The fuse is a Schurter 6.3V 2
Amp or equivalent (Schurter part number 3402.0012). Turn the system power off and either remove the
EPC-31/32 from the system or remove the external power connector before attempting to replace the fuse.
Some floppy drives can be powered through the data cable. This provides a convenience to the user so
that an external power supply is not needed. These drives connect VCC through pins 7,9, and 11 of the
cable. Other drives connect GND to these pins. The EPC-31/32 supports both types of floppy drives.
However, care must be taken when connecting the EPC-31/32 to the floppy so that VCC and GND are not
shorted together. In particular, be careful with floppy drives that provide jumpers to configure whether
VCC or GND is connected to these signals. If you are unsure which type of drive you have or don't know
how the jumpers are configured for a specific drive, determine this from the drive specifications before
connecting the drive to the EPC-31/32.
CALYON
This fuse is not installed when the unit is shipped. If you are using a floppy disk drive that is powered
through the ribbon cable, be sure to install the fuse. If your floppy disk drive is powered through a power
cable, do not install the fuse.
SVGA Video Controller
An SVGA video and flat-panel display controller is optional on the EPC-31/32. The controller is
implemented with a Chips and Technologies (C&T) 65535 controller. The 65535 controller supports
virtually all flat panel displays, including single and dual scan monochrome LCD's, EL and plasma
displays, and STN and TFT color LCD displays, as well as analog VGA monitors.
The SVGA controller resides on the 32-bit 486 local bus. The 512 KBytes of video memory is
implemented with a single 256kxl8 DRAM device. This memory provides standard VGA modes on a
CRT or flat panel display, with up to 640x480 resolution in 256 colors. It also provides super VGA modes
up to 1024x768 on flat panel displays, and CRT displays of 800x600 256 colors, and 1024x768 16 colors.
A standard 15-pin high-density D-sub connector, accessible on the AT-card bracket is provided to connect
to a standard VGA monitor. A 50-pin .079 w [2.00 mm] pitch ribbon-cable header is also present on the
board to provide connection to a flat panel display.
The ROM BIOS code for the SVGA controller is included in the same BIOS flash EPROM that the main
system BIOS resides in. The default setting supports a standard VGA CRT monitor. It is possible to
change the video BIOS support flat-panel displays after the board has left the factory. Refer to flash
BIOS Upda(ing{^\z\ in this chapter for more information.
Flat Panel Support
The EPC-31/32 supports a wide variety of flat panels using the onboard flash to contain the video BIOS.
This onboard flash is updated using the floppy disk supplied with the EPC-31/32.
There is no DC-DC converter onboard for use in adjusting the flat panel voltage. If your flat panel requires
adjustment, you will need a DC-DC converter with a trimpot.
Many flat panels require 600 VAC for backlight. If your flat panel falls in this category, you will need to
provide an inverter. Inverters are available from the flat panel supplier.

Due to the wide variety of flat panels on the market, you must provide your own ’’custom" cable. At this
printing, flat panel manufacturers have not standardized on any one cable or connector. Refer to Appendix
D, Video Modes and Supported Pane/siai more information.
Rash Disk Subsystem
Two 8-megabit flash memory devices may be factory installed on the EPC-31/32.
This flash memory is not located in the processor's memory address space; it is accessed indirectly through
I/O reads and writes. Single byte I/O writes to 0x360-0x382 are saved in latches that setup the lower,
middle, and high address bits that drive the flash memory's address lines. I/O reads/writes to 0x383 access
the flash data at the address stored in the latches. These latches contain indeterminate data at power-up,
and are not cleared by a system reset.
This architecture is compatible with the flash system architecture used on other RadiSys products.
Reading the flash file system is performed using the standard DOS disk INT calls. The flash disk appears
as the "C:" or "D:” drive, depending on the setup screen entry.
NOTE: +12V must be supplied via the ISA-bus (or the IS Abus headers) to allow erasing and writing the
flash disk device.
EPC-31/32 Utilities Diskette Contents
The utilities diskette contains the following flash format files:
XFORMAT.EXE Flash formatting program
BB5.00 Boot block files for DOS 5.0
BB6.00 Boot block files for DOS 6.0,6.1, & 6.2
README.TXT Additional user information added after the
manual was printed
Additional flat panel support files are listed later in this chapter.
Onboard Flash Utility Installation
Create a directory on the C: drive called C:\FLASH (or another name you choose). Copy the flash files
from the distribution diskette to the C:\FLASH directory.
Formatting Program
In order to format the EPC-31/32 onboard flash, use the program named XFORMAT. It is distributed on
the floppy diskette shipped with the EPC-31/32. Note that this software is also used with the RadiSys
EXM-2A flash memory module, where both flash and SRAM memory are formattable. Ignore all
references to formatting SRAM memory.
When xformat is used to format flash memory, the function first erases all flash memory, formats it,
optionally adds system files to make it a boot device, and then copies a directory structure and files into it.
The program is invoked with the following command line:
XFORMAT [options] [srcdir]
All files in directory srcdir (typically a directory on your hard disk) and all of its subdirectories (if any)
and their files are copied into the EPC-31/32. To make changes to the flash disk you must rerun the
XFORMAT function.
Each file is created with the same attributes and dateAime stamp as the source file, except the files are also
marked as read-only and unarchived (see the DOS ATTRIB command for more information).
The following flags are available when using the XFORMAT function. Note that a dash (-) can be used
interchangeably with a slash (/) to set flags.
/B=<sysdir> Boot Disk Flag. Creates a bootable disk image using the DOS system files specified by
the <sysdir> parameter. The function formats and copies files to the formatted disk. A
bootable disk image is created. The operation fails if it cannot find the operating
system files.
It is possible to create a bootable disk image from a non-bootable source drive. Contact
RadiSys Technical Support for details.
/F<name> <size>
File Output Flag. Outputs the disk image to the file <name> with size <size>. <size> is
a hex value that specifies the number of Kbytes in the target file. This option is useful for
creating VME memory disks and images for users that are going to write their own flash

writing program, and is documented here for completeness.
/H Help Flag Displays a list of available flags and their options. Ignore all references to
SRAM memory and the EXM-2A.
/N=<ver> Non-Boot Version Flag. Creates a bootable disk image using the boot block file specified
by the <ver> parameter. (The location of the boot block file is specified by /B or /S
flags.) This option is useful for creating bootable flash disks from non-bootable sources
such as network and RAM disk drives (see Appendix D for more information on creating
bootable images from non-bootable disks). The boot block file for /N=5 is BB5.00 (DOS
5) and the boot block file for /N=6 is BB6.00 (DOS 6.X). The boot block files are
supplied with the EPC-31/32 flash diskette. This operation fails if it cannot find the
operating system files.
/P=<slot> Position Flag. Not applicable to this product. (This flag is only for use when
XFORMAT is operated with an EXM-2A, and refers to the EXM slot number.)
/Q=m Quiet Mode Flag. Suppresses progress display messages. May be combined with the No
Reboot Flag (i.e., /Q=mr).
/Q=r No Reboot Flag. Suppresses reboot upon successfiil completion. May be combined with
the Quiet Mode Flag (i.e., /Q=rm).
It is necessary to flush the DOS buffer areas prior to accessing newly formatted disks. This
is accomplished by rebooting. This reboot suppression flag is strictly for use when
XFORMAT is used in a batch file where the reboot command is at the end of the batch
file.
/S System Flag. Creates a bootable disk image using the DOS system files on the disk that
XFORMAT is invoked from.
This operation fails if it cannot find the operating system files.
/T= < type > Type Flag. Specifies the type of format to be performed. When <type> is S, the function
formats the SRAM. When <type> is O, the function formats the onboard flash (flash
memory on the CPU board). When /T-O is selected, the fP flag is not allowed.
NOTE: You must specify option O when formatting the EPC-31/32 onboard flash.
/V Volume Label Flag. Prompts for a disk volume label. A volume label identifies the disk
and can be a maximum of 11 characters. The label conforms to the MS-DOS convention,
thus the following are not allowed: *.+,:;<> = ?[]\/|() A & . Label letters are
converted to upper case.
Note that not all flags are valid for every system. For example, /T=0 is used only for systems that contain
onboard flash memory (i.e., flash memory on the EPC-31/32 CPU).
Some examples of the XFORMAT invocation are described below.
XFORMAT ZB-AA A:\
Formats the EXM-31/32 flash memory as a DOS system disk from the DOS system disk in drive A:, and
copies all files from device A: into the EPC-31/32 flash (including subdirectories).
XFORMAT A:\
Formats the EXM-31/32 flash memory and copies all files from device A: into the EPC-31/32 flash
(including subdirectories). The EPC-31/32 flash will not be bootable if not formatted with the /S or /B flag.
XFORMAT /N=6 /b=D: C:\FLASH
Format the flash memory using the system files and the boot block file BB6.00 from directory D:\ and copy
all files from C:\FLASH. Note that you cannot simply copy a file to a flash disk. You must use XFORMAT
to erase, format, and copy the contents of a directory to the flash disk.
Unless the /F option is selected, XformAT automatically determines the amount of available space on your
EPC-31/32 flash. It also calculates the amount of space needed for the files to be copied, and aborts without
erasing the EPC-31/32 flash if there is insufficient space.
XFORMAT aborts if the source device (for either the file copy or for the system files) is the same EPC-
31/32 flash being formatted.
Since the EPC-31/32 flash is represented to DOS as a fixed (non-removable) disk, DOS may have buffered
data from the EPC-31/32 flash's files prior to its being formatted. As a result, you should reboot your
system prior to accessing files in a newly formatted EPC-31/32 flash.
XFORMAT Error Messages
The following messages may display during error conditions using XFORMAT.EXE .

Error Message BATTERY NEEDS REPLACEMENT
Explanation The XFORMAT program detected that the battery power is below 2.5V.
Resolution Replace the battery. Refer to Figure 4 for procedure and Appendix A for location.
Error Message CANNOT READ COMMAND.COM
Explanation COMMAND.COM could not be located.
Resolution Copy COMMAND.COM to the appropriate directory and re-invoke XFORMAT
Error Message <path> COMMAND.COM WILL NOT BE COPIED TO THE TARGET
Explanation A version of COMMAND.COM was found in the top directory of the <srcdir>.
Resolution Delete COMMAND.COM from the <srcdir> directory and re-invoke XFORMAT
Error Message INSUFFICIENT SPACE ON TARGET DEVICE
Explanation The source directory is too large to fit onto the target.
Resolution Remove some of the files from the source directory.
Error Message INVALID SOURCE PATHNAME
Explanation XFORMAT could not find the directory specified as the source pathname.
Resolution Ensure that the source pathname exists.
Error Message INVALID TARGET SIZE SPECIFIED
Explanation An illegal character was detected in the file size portion of the /F parameter
Resolution Specify the file size using only hex characters.
Error Message MORE THAN ONE SOURCE PATH WAS SPECIFIED
Explanation Multiple source paths were detected on the command line.
Resolution Remove one of the source paths from XFORMAT's invocation line.
Error Message NO ARGUMENTS SPECIFIED
Explanation The command line does not specify any operations.
Resolution Execute XFORMAT with /H to display flags and options.
Error Message SOURCE PATHNAME TOO LONG
Explanation Insufficient storage for the pathname string.
Resolution Copy the files to a directory that is closer to the root.
Error Message SYSTEM DOES NOT CONTAIN ONBOARD FLASH
Explanation /T=0 was specified for a system that does not contain onboard flash (flash on the CPU
card).
Resolution Check that onboard flash is present and try again.
Error Message TARGET SIZE NOT SPECIFIED
Explanation The /F option is ill-formed.
Resolution The syntax for the /F flag is /F<filename> <size>. The filename is specified and is
followed by the file size in kilobytes.
Error Message UNABLE TO INITIALIZE FLASH DEVICE
Explanation XFORMAT cannot write to flash memory if no power is present. Or, no flash memory
exists.
Resolution Check that the system is properly connected to a +12V power supply.
Error Message UNABLE TO READ BOOT RECORD FILE
Explanation The boot record files are not in the <srcdir> path.
Resolution Copy the boot record files to the proper directory

For this example, assume that you are updating the BIOS on the system that is running NEWBIOS.EXE.
Therefore, to update the BIOS in self-hosted mode, follow the instructions below:
1. Insert the EPC-31/32 BIOS update diskette in drive A.
2. Switch the command line to drive A by typing A: and pressing <ENTER>.
3. Display the contents of the NEW.BAT file by typing TYPE NEW.BAT and press <ENTER>.
The first time you perform this step, the following default file contents display:
NEWBIOS /F=FILL16.BIN /F=VCRT31.BIN /F=EPC31.BIN /F=FILL8.BIN
4. You MUST edit the NEW.BAT batch file to select the appropriate system and VGA BIOS from the
list of files below. Note that VCRT31.BIN does not exist on the Utilities diskette; you MUST
replace this file name with the appropriate VGA BIOS that matches your panel type. For standard
desktop VGA monitors, use VCRT.BIN. Otherwise, if using a flat panel, choose the appropriate flat
panel file. Even if you are only updating the system BIOS, you must still place a VGA binary in the
file Make sure the new VGA BIOS you are using is the exactsizevfc VCRT31.BIN (32,768 bytes).
5. Run the NEW.BAT file to begin the update.
6. The following message displays: "You have selected to update this computer's BIOS. Is this correct?
(Y/N): "
Select Y for yes if you are ready to proceed. Proceed to the next step. Select N for no if you want to
re-check the NEW.BAT contents; go back to step 3.
7. Each file name included in NEW.BAT displays as the program executes.
8. This message displays: "Update completed successfully. Press any key to reboot."
Press any letter or number on the keyboard. The system reboots using the new BIOS. Use this same
procedure to update the BIOS using the remote download procedure, making sure to include the port
designation (/P= ) as discussed above.
These files are included for system updating with the EPC-31/32 utilities diskette:
NEW.BAT Self-hosted update batch file
VCRT.BIN 32 KBytes Standard CRT VGA BIOS
VU64QU3.BIN 32 KBytes VGA BIOS for Sharp 640U3 flat panel
VLM64C08.BIN 32 KBytes VGA BIOS for Sharp 64C08 flat panel
VLM64P80.BIN 32 KBytes VGA BIOS for Sharp 64P80 flat panel
VLQ10DH1.BIN 32 KBytes VGA BIOS for Sharp LQ10DH11 flat panel
NEWBIOS.EXE Flash BIOS update program invoked from NEW.BAT
FILL8.BIN 8 KBytes fill file for unused portion of flash device
FILL16.BIN 16 KBytes fill file for unused portion of flash device
EPC31.BIN 64 KBytes EPC-31/32 System BIOS
Refer to the README.TXT file on the floppy for additional information. Note that you cannot use the
NEWBIOS.EXE file on this Utilities diskette with any other RadiSys EPC, and you can only use
NEWBIOS.EXE shipped on the EPC-31/32 Utilities diskette on the EPC-31/32.
Peripheral Interfaces
Serial and parallel port functions, a floppy disk drive controller, and decode logic for an IDE interface are
contained in a muIti-IO chip, the FDC37C651, manufactured by Standard Microsystems Corp. (SMC).
For details of the operation of these functions, refer to the SMC data sheet for this device.
The COM1 serial port is located in the I/O address range Qx3F8-0x3FF. COM1 serial port interrupts are
signaled using IRQ4. Connection to COM1 is provided by a standard male DB-9 connector mounted on
the card bracket. The COM2 serial port is located in the I/O address range 0x2F8-0x2FF. COM2 serial
port interrupts are signaled using IRQ3. Connection to COM2 is made via a standard header connector on
the board that is shared with the parallel port.
Both COM ports are 16C550-compatible and contain 16-byte FIFOs. Hie best way to bring up the FIFO is
to set it up within the applications software, but if that is not possible it can be set through the debug (or
equivalent) routine. Writing to 0x3FA with the hex value 01 enables the COM1 FIFO; writing to 0x2FA
with the hex value 01 enables the COM2 FIFO.

Error Message UNRECOGNIZED FLAG
Explanation A mis-spelled or illegal flag was used.
Resolution Check the command line to ensure only legal flags are used.
Any function or application other than XFORMAT that attempts to write to the flash disk will cause the
system to lock up. Typical applications that write to disk might be Norton Utilities or PC Tools; typical
DOS functions would be COPY, XCOPY, FORMAT, and FDISK.
The flash portion of the EPC-31/32 is visible to the operating system as a separate logical drive.
Applications that read the flash memory operate identically as if they were reading any "read only" media,
such as CD-ROM disks.
Hash BIOS Updating
The EPC31/32 supports flash BIOS updates for both system and VGA BIOS. These updates are
accomplished by running the NEW.BAT file, found on the EPC-31/32 utilities diskette. NEW.BAT calls
the DOS executable NEWBIOS.EXE
The Utilities diskette contains two subdirectories, \FLASH and another subdirectory named using a 5-
digjt number to indicate the BIOS level included on the diskette. At this writing, this subdirectory is
S30600 (BIOS version 3.06.00).
The NEWBIOS program executes in either self-hosted or remote download modes. Self-hosted mode is
for updating the flash BIOS of the system in which the NEWBIOS program is executing and is the
default mode.
Remote download operations are only necessary for reprogramming a BIOS damaged by power failure
during a previous update process, or if a floppy drive is not present in the EPC-31 system. Remote
download requires a remote PC connected by a NULL modem cable to the EPC-3iy32's COM1 port, and
the command line must contain the /P parameter to indicate which port is to be used on the computer
running the NEWBIOS program (not the COM port on the EPC-31/32). Fbr example, use /P = 1 for
COM1 on the source computer. Note also that when performings remote download, you must set the
Update BIOS prompt in the BIOS setup to [ENABLE]. Refer to page 8, Update BIOS
NEWBIOS can run from the floppy drive or the hard disk. To install the update files on your hard disk,
create a subdirectory on your hard disk drive and use the DOS COPY command to copy the files from the
N30600 directory. To display the usage model, type NEWBIOS and press <ENTER>. Available options
include:
NEWBIOS/F=<filelist> [/C-timeout] [/R=retiies] [/P=port]
/C = <ms> Wait period. Default is 30000 milliseconds.
/R = <count> Retries. Default is 16 retries.
/P = <n> COM port used on the source computer for remote downloads.
If no port selection is made using the /P=Poit # parameter, NEWBIOS begins execution in self-hosted
mode. NEWBIOS reprograms 120 Kbytes of the 128K flash BIOS. The first 8 Kbytes are used for the
boot block and are not reprogrammable.
Download files are specified by using the /F=<filename> parameter. Files are copied into flash memory
from low to high memory addresses. The files list must provide for the necessary files, in the correct
order, and located at the correct offsets. To help accomplish this, two files (FILL16.BIN and FILL6.BIN)
are included on the Utilities diskette.
The necessary order and offsets are as follows:
Offset
File
Ellefr) to Use
0 16K 'filler"
FILL16.BIN
16K
32K video BIOS
video BIOS + filler as needed to achieve 32K
48K
64K system BIOS
EPC31.BIN
112K
8K "filler"
FILL8.BIN
Note that the video BIOS must consume a total of 32 Kbytes. If the video BIOS file is less than 32 KB,
you must fill it to a total of 32K. For example, if the video BIOS is only 31K, you must ”pad w the file
with NULLs until the file size is exactly 32 KB (32,768 bytes). If the video BIOS is only 24KB, you may
use an additional FILL8.BIN entry to consume the remainder of the 32 KB required before the system
BIOS is installed. It could be necessary to combine both these techniques depending on the particular
video BIOS chosen.

The parallel port is located in the I/O address range 0x378-0x37A. Parallel port interrupts are signaled
using IRQ7. Connection to this port is made via a header connector on the board that is shared with the
COM2 serial port. The parallel port is bi-directional.
The floppy disk controller is fully PC-compatible, supporting one or two floppy drives. It occupies I/O
addresses 0x3F2,0x3F4,0x3F5, and 0x3F7. It uses bus interrupt IRQ6 and the 8-bit DMA channel
corresponding to DRQ2 and ~DACK2 on the AT bus. Connection to a floppy disk drive is made via a
standard 34-pin ribbon cable header mounted on the PCB. Power for the drive may be provided through
a socketed SMT fuse via the cable. If the power via the cable is not desired, the fuse is removed from the
socket. If power is provided through the ribbon cable, only one floppy drive can be connected and must
use a straight ribbon cable, not a twisted ribbon cable. Using a twisted ribbon cable will blow the fuse.
The IDE interface is mapped to I/O addresses OxlFO - 0xlF7,0x3F6, and 0x3F7. Note that I/O address
0x3F7 is shared with the floppy disk controller as required for PC compatibility. The IDE hard disk uses
interrupt IRQ14. Connection to an IDE hard disk is made through a 44-pin 0.079" [2.0 mm] pitch ribbon
cable header (the standard for 2.5" and 1.8" HDD's) mounted on the PCB.
ISA bus
The ISA bus signals are provided by the VLSI VL82C486 and VL82C114 IC devices. No additional
buffering is required or provided. The VL82C486 supports programmable AT-bus buffer drive capability.
This design sets the buffer strengths, Iol and Ioh, to 12mA.
The clock speed of the ISA bus will be set to 8.0 MHz.
Terminations contained on the EPC-31/32 CPU board are as follows:
Signals Termination
Address lines SA0 - SA19, and LA17 - LA24: 10k pullup to VCC
Data lines SD0 - SD15: 10k pullup to VCC
Control strobes -TOR, ~IOW, -MEMR, -MEMW: 4.7k pullup to VCC
Control strobes -SMEMR and -SMEMW are totem-pole outputs and require no termination
Xfer response signals -IOCS 16, -MEMCS16, ~0WS, -MASTER: 300 ohm pullup to VCC
DRQ inputs: Approximately 10k pullup to VCC, internal to VL82C486
IRQ inputs: Approximately 10k pullup to VCC, internal to VL82C486
-REFRESH output: Open-collector, with 300 ohm pullup to VCC
RESETDRV, OSC, BALE, AEN, SYSCLK, and TC are totem-pole outputs and require no
termination
-SBHE output: 10k pullup to VCC
—IOCHCK input: 4.7k pullup to VCC
IOCHRDY input. Ik pullup to VCC
Table 4. EPC-31/32 Terminations.
Note that pullups are provided on lines driven by the "current master" in order to place these lines in a
known state during the transfer of control to an ISA-bus add-in card that uses the MASTER feature to gain
control of the bus from the CPU.
NOTES

4* Connectors
Overview
This chapter specifies the pin-outs of the connectors on the EPC-31/32. These connectors adhere to
existing standards. Pins are labeled from the point of view of looking into the front of the connector on
the EPC-31/32. Refer to Appendix A for the board location of each connector.
The following table lists each connector (or equivalent) and the part number for the suggested mate:
Ref. Function On PCB Suggested Mate
J1 VGA JST KSEY-15S-1A3F19-13 AMP 748364-1
J2 COM1: JST JSEY-9P-1A3F19-13 AMP 205204-4
J3 KBD: JST MD-S6100-90 AMP 750206-4
CN1 HDD Samtec STMM-122-01-S-D-20 3M152244-0110-GG
CN2 FDD 3M 2534-6002UB 3M 3414 6600
CN3 COM2/LPT 3M 2534-6002UB 3M 3414 6600
CN4 Misc. 3M2514-6002UB 3M 3385-6600
CN5 Flat PanelSamtec STMM-125-01-S-D 3M 152250-0110-GG
CN6 Power AMP 171826-4 AMP 1718224
CN7 AT CD Header Samtec TSW-132-07-S-D Samtec SSW-132-01-G-D
CN8 AT CD Card Edge N/A AMP 645169-2
CN9 AT AB Header Samtec TSW-120-07-S-D Samtec SSW-120-01-G-D
CN10 AT AB Card Edge N/A AMP 645169-2
Note that CN8 and CN10 are on the same card edge. Where applicable, each connector drawing has a label
for the ”top” of the EPC-31/32, or opposite of the gold-plated bus connectors, and the "bracket” side,
meaning the edge of the board with the COM and SVGA connector.
IDE Hard Disk Drive Controller
IDE HDD pin-out (CN1): 22x2,0.079" [2.0 mm] pitch header
1 -RESET 2
GND
3 D7 4
D8
5 D6 6
D9
7 D5
8
D10
9 D4
10 Dll
11 D3 12
D12
13
D2 14
D13
15 D1
16 D14
17 DO
18 D15
19
GND 20
key
21 n/c
22 GND
23 -IOW
24 GND
25 ~IOR
26 GND
27
IOCHRDY
28
29 n/c 30
GND
31 IRQ
32 -IOCS
33 A1
34
-PDIA
35 A0
36 A2
37
—HCSO
38
-HCS1
39
-DASP 40
GND
41
vcc 42
VCC
43
GND 44
n/c
Table 5. IDE Hard Disk Drive Connector Pin-out.
CN1 Bracket