BC 4035
Chapter 4 - Technical Reference

BIOS

An American Megatrends, Inc. (AMI) system BIOS with embedded setup and hard disk setup utilities resides in EPROM on the board. At boot time, the data can be transferred to shadow RAM. This provides increased system performance, since RAM access is faster than EPROM access.

POST Display

The BC has eight LEDs arranged in two groups of four (refer to the illustrations in the Board Identification section of Chapter 1 for LED location). As the system proceeds through its Power On System Test (POST) these LEDs display binary codes which can be used to diagnose board failures. Refer to Appendix A for a description of these codes.

Memory - Hardware

All BC system memory is provided in 72-pin by 36-bit standard 70ns SIMM modules. These SIMMs are defined in Table 4-1.

Table 4 - 1
SIMM Definitions

SIMM Configurations

The SIMM configurations supported the BC 4035 are represented in Table 4-2.

Table 4 - 2

Memory Management

Memory between 640 KBytes and 1 MByte not required by hardware memory windows or BIOS can be made available to the installed memory manager. By configuring these areas as EMS page frames or Upper Memory Blocks, they can be used for loading and executing application software such as TSRs (Terminate and Stay Resident programs) and network drivers.

Memory maps for the BC 4035 processor are illustrated in the following figures.

BC 4035 Memory & I/O Configurations

BC4035 Memory Map

BC 4035 Memory Map

BC 4035 I/0 Map

Table 4 - 3

Video Controller

The BC 4035 contains an extended high resolution video graphics controller. Table 4 - 4 defines the video support provided on each processor.

Table 4 - 4

Video Support

Refer to Chapter 3 - Installation for information on available video driver.

Keyboard/Mouse Controller

The BC has a PS/2 compatible keyboard controller with the AMI keyboard BIOS. The keyboard controller uses IRQ 1 for its interrupts, and requires no DMA channel.

The keyboard controller also supports a PS/2 compatible mouse which uses IRQ 12. Switch S2 is used to enable the PS/2 mouse interrupt on IRQ 12 (refer to Chapter 2 for switch settings).

IDE Hard Drive Interface

An IDE hard drive interface is included on the BC for applications that require a hard disk drive. IDE drives include an AT compatible disk controller. /The IDE interface circuit will support one or two IDE drives. The hard disk controller uses IRQ 14 for its interrupt. When adding an IDE drive to the board, use the AMI BIOS setup program to select the drive type. See the American Megatrends, Inc. BIOS Configuration Program User's Guide for information on selecting IDE drive types.

The BC CMOS must be configured to properly set up the IDE interface. In the Standard CMOS Setup section, hard disk types for C: and D: must be entered. If a disk is not present, select "Not Installed". This should be done, for example, if the only hard drive in the system is a SCSI drive. ISA processors also require that the IDE interface be "Enabled" in the Peripheral Management Setup section (if no disk is present set the IDE interface to "Disabled").

To recover IRQ 14, all IDE drives must be removed from the 40-pin header cable.

Floppy Disk Controller

The BC contains a PC/AT compatible floppy disk controller that supports all PC/AT floppy disk configurations. It is configured for industry standard single-speed floppy disk drives, and supports up to two of any combination of 5.25 or 3.5 inch drives. The BIOS setup program must be configured for the proper drives. The floppy controller uses IRQ 6 for its interrupt and DRQ 2 for its DMA channel. ISA processors allow the floppy disk controller to be disabled in the Peripheral Management Setup section of the System BIOS CMOS setup program (refer to the American Megatrends, Inc. BIOS Configuration Program User's Guide).

BC4035 and BC 4035A IDE Support

The AMI BIOS on the BC 4035 has been updated to provide enhanced IDE support. The same BIOS is now provided on both the BC 4035 and the BC 4035A.

To determine which BIOS is included on a BC 4035, boot the board and watch the sign-on message. If the date displayed is March 10, 1995 or later, the BIOS supports the enhanced IDE interface. Otherwise, enhanced IDE support is not provided. All BC 4035A boards include the updated BIOS.

The BC 4035 and BC 4035A enhanced IDE features included in the March 10, 1995 AMI BIOS are described below. The options may be enabled or disabled via the BIOS setup.

Block mode (multi-sector) transfer

To increase system performance, enable the block mode option. If the hard disk supports multi-sector transfers, BIOS will enable the multi-sector transfer for read/write commands.

LBA mode (for hard disks larger than 528 Mbytes)

Previous versions of the BIOS did not support disk drives larger than 528 Mbytes. To use larger drives with the new BIOS, configure the drive type (use type 47 for a user defined drive and set the cylinders, sectors, and heads as recommended by the disk drive manufacturer). Enable the Logical Block Assignment (LBA) mode for each drive that is larger than 528 Mbytes (this option may be configured separately for each drive). Do not configure this option for drives that are 528 Mbytes or smaller.

Recommended Configuration

Enable the options for block mode (multi-sector) transfer. For each disk greater than 528 Mbytes, enable LBA mode.

Serial and Parallel Ports

Two serial ports and a parallel port are available on the BC processor board. One serial port is accessible through a standard DB-9 connector on the rear bracket (J 11). The other serial port (COM2) and the parallel port (LPT1) are accessible internally through header connectors (J8 and J7). All ports comply fully with PC/AT interrupt and I/O port standards. External access to the internal I/O connectors (COM2 and LPT1) is accomplished through Cubix-supplied adapter boards. Refer to the sections Optional LPTI and Optional COM2 and Mouse in Chapter 3 for more information Contact the Cubix Sales department to order the serial or parallel port adapter product required to access the COM2 or LPT1 ports.

Use the Peripheral Management Setup section of the System BIOS CMOS setup program to configure the serial and parallel ports (refer to the American Megatrends, Inc BIOS Configuration Program User's Guide).

Ethernet Controller

The BC is equipped with an integral Ethernet controller with a 10BASE-T RJ-11 connector (J13) on the mounting bracket at the rear of the card. Software drivers are provided for this controller to support PC local area networks.

Near the RJ-45 connector and visible through a slot in the mounting bracket are two light emitting diodes. The green LED will light when the interface has a valid connection to a 10BASE-T hub. The orange LED will light whenever the Ethernet controller detects data on the receive lines. These LEDs can be useful indicators of network activity.

Ethernet Drivers

A BC Series 10BASE-T Driver Diskette included with the BC contains drivers for the following network operating systems:

• Novell NetWare v3.x, v3.x
• Microsoft LAN Manager
• Microsoft Windows NT
• Microsoft Windows for Workgroups v3.1, v3.11
• Banyan VINES (client support only)
• IBM LAN Server
• Sun PC-NFS
• Artisoft LANtastic v4.x, v5.x
• Packet Driver
• A Unix Streams driver for SCO Unix is also available from Cubix Customer Service.
• The Microsoft NDIS driver supports NDIS compatible networks, including DEC Pathworks.

The different drivers and associated software are stored in subdirectories on the diskette. The appendices of this manual include installation procedures for each network. These installation instructions are intended to provide examples to aid the installer. Procedures for installing the drivers for each particular network configuration vary.

Ethernet Configuration

The ISA based Ethernet adapter is a bus master device which gains control of the ISA bus to transfer data between the CPU and the network by DMA. This Ethernet adapter uses 24 I/O port addresses starting at 300 hexadecimal. The adapter also uses DMA channel 5. The I/O addresses and DMA channel cannot be changed, but they can be disabled if the Ethernet controller is not used. An interrupt is required; the interrupt level is a switch selectable choice between IRQ 3 and IRQ 5. Refer to Chapter 2 for switch configurations.

For diskless installations in a Novell environment, the BC 4035 contain remote boot software which may be enabled in the CMOS setup program in the "Advanced Chipset Setup" section. In this section’s setup screen the "On board LAN BIOS boot" must be "enabled" if the BC is to boot from a Novell NetWare file server. All local boot devices must be disabled for this function to work. This means that C: and D: must be set to "Not Installed" in the "Standard CMOS Setup" section.

The Ethernet controller does not use a shared memory window on the CPU. (The Novell remote boot option does use a memory window if it is enabled.)

The BC 4035 Ethernet adapter can be configured as shown in Table 4 - 7.

Table 4 - 7
BC 4035 Ethernet Configuration Options

*Default Setting

The Base I/O Address and DMA Channel settings are fixed and cannot be changed. To use another device in the ISA bus at these settings, disable the Ethernet controller. The Ethernet controller should be disabled if it is not to be used for network communications. The Ethernet controller functions are selected with Switch S2 as described in Chapter 2.

Line Busy

The Cubix Line Busy RJ-11 jack is designed to be connected to the phone line that attaches to a modem. Its purpose is the make the telephone line appear busy when the processor or modem is not ready to answer an incoming telephone call.

The Line Busy circuit is inserted in parallel with the telephone line from the PBX to the modem. The Federal Communications Commission (FCC) has registered this circuit for use on PBX systems only and not for direct connection to the Public Telephone Network.

The Line Busy circuit is designed to be used on rotary PBX systems to keep incoming calls from ringing on line that will not answer. The circuit uses Data Terminal Ready (DTR) from the Cubix processor’s communication port to determine whether the processor is ready for a call. If DTR is false, the circuit creates an off-hook condition on the telephone line to force the rotary PBX to bypass this extension for an incoming call. When DTR is true, the Line Busy Circuit will terminate the off-hook condition, and the processor will respond to an incoming call. The Line Busy circuit on the BC is controlled by the COM1 DTR signal. The COM2 port has no effect on Line Busy.

Cubix processors assert DTR false on the reset operation. It is the responsibility of the communications application running in the processor to assert the DTR signal true.

Line Busy Installation

1. Connect the PBX modular telephone cable to the "Line" input of the modem.
2. Connect the modular telephone cable from he modem’s "Phone" jack to the RJ-11 jack on the BX (J12). See Figure 4.- 2.
3. If the modem phone jack is unavailable, a "T" modular jack can be uses as shown in Figure 4 - 3.

Figure 4 - 2

Line Busy Circuit Connected Via Modem Phone Jack

Figure 4 - 3

Line Busy Circuit Connected with "T" Jack

CMOS Battery

The BC has an internal battery that backs up the real time clock and CMOS memory. No external battery is required to retain date, time of day or setup information.

Speaker

The BC has a connection for an eight ohm permanent magnet type speaker. The speaker signal is the standard AT speaker output.

System Interrupts

The 16 system hardware interrupts on the BC are represented in Table 4 - 8. Interrupts are managed by two standard 8259A Programmable Interrupt Controllers (PICs). Interrupts at IRQ 0 through 7 are located on the main PIC IRQ 8 through 15 are on the save PIC.

Table 4 - 8
BC Interrupt Configuration

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