DIGITAL-LOGIC AG

MSB900/L Detailed Technical Manual V1.0

5.4.3.Serial Ports COM1-COM2

The serial channels are fully compatible with 16C550 UARTS. COM1 is the primary serial port, and is sup- ported by the board's ROM-BIOS as the PC-DOS 'COM1' device. The secondary serial port is COM2; it is supported as the 'COM2' device.

Standard: COM 1/2: National PC87317VUL: 2 x 16C550 compatible serial interfaces

Serial Port Connectors COM1, COM2

Pin

Signal Name

Function

in/out

DB25 Pin

DB9 Pin

1

CD

Data Carrier Detect

in

8

1

2

DSR

Data Set Ready

in

6

6

3

RXD

Receive Data

in

3

2

4

RTS

Request To Send

out

4

7

5

TXD

Transmit Data

out

2

3

6

CTS

Clear to Send

in

5

8

7

DTR

Data Terminal Ready

out

20

4

8

RI

Ring Indicator

in

22

9

9

GND

Signal Ground

 

7

5

The serial port signals are compatible with the RS232C specifications.

5.4.4.Floppy Disk Interface

This is not available with this product; use a USB Floppy.

5.5.Controllers

5.5.1.Interrupt Controllers

An 8259A compatible interrupt controller, within the chipset, provides seven prioritized interrupt levels. Of these, several are normally associated with the board's onboard device interfaces and controllers, and sev- eral are available on the AT expansion bus.

Interrupt:

Sources:

 

Onboard used:

 

IRQ0

ROM-BIOS clock tick function, from timer 0

 

yes

 

IRQ1

Keyboard controller output buffer full

 

yes

 

IRQ2

Used for cascade 2. 8259

 

yes

 

IRQ3

COM2 serial port

 

yes

 

IRQ4

COM1 serial port

 

yes

 

IRQ5

LPT2 parallel printer (if present)

 

no *

 

IRQ6

Floppy controller

 

yes

 

IRQ7

LPT1 parallel printer

 

yes

 

IRQ8

Battery backed clock

 

yes

 

IRQ9

Free for user

 

no *

 

IRQ10

Free for user

 

no *

 

IRQ11

Free for user

 

no *

 

IRQ12

PS/2 mouse

 

yes

 

IRQ13

Math. coprocessor

 

yes

 

IRQ14

Hard disk IDE

 

yes

 

IRQ15

Free for user

 

no *

 

 

 

* It may depend on the LAN configuration.

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Compaq MSB900L user manual Serial Ports COM1-COM2, Floppy Disk Interface, Interrupt Controllers

MSB900, MSB900L specifications

The Compaq MSB900 and MSB900L are noteworthy entries in the realm of personal computing, particularly for their cutting-edge features and innovative technologies that defined their era. Positioned as versatile desktop solutions, both models have garnered attention for their robust performance and user-friendly design.

The Compaq MSB900 is equipped with a powerful processor that enhances multitasking efficiency. Its architecture supports a range of demanding applications, making it suitable for both professional and everyday use. Users can expect a seamless experience whether working on complex spreadsheets or engaging in casual gaming.

In terms of memory, the MSB900 boasts expandable RAM options, allowing users to enhance their system's capabilities as needed. The availability of multiple RAM slots provides flexibility for upgrades, ensuring the system can keep pace with future software requirements. Storage solutions in the MSB900 include high-speed hard drives, which contribute to fast boot times and robust data retrieval.

The MSB900L variant steps up the performance with additional features tailored for power users. It incorporates advanced graphics capabilities, offering superior visual experiences for gaming and multimedia applications. The dedicated graphics card provides a substantial boost in rendering performance, making it a worthy choice for graphic designers and video editors.

One of the standout characteristics of the MSB900 and MSB900L is their commitment to connectivity. Both models come equipped with a wide array of ports, ensuring compatibility with various peripherals. This includes USB ports for modern devices, Ethernet ports for wired networking, and legacy connections for older technology, catering to a diverse user base.

Energy efficiency is another key feature of these models. Designed with power-saving technologies, the Compaq MSB900 and MSB900L aim to reduce energy consumption without compromising performance. This focus not only helps to lower operating costs but also aligns with growing consumer preferences for environmentally conscious products.

In summary, the Compaq MSB900 and MSB900L offer a compelling combination of performance, expandability, and connectivity. Their innovative features and user-friendly design make them suitable for a wide range of users, from casual consumers to professional power users. As a testament to Compaq’s legacy, these models continue to be regarded as reliable choices in the personal computing landscape.