DWZZH 16–Bit UltraSCSI Hub (Rack-Mountable)

After all the IDs in the group have been serviced, a new group of IDs will be captured at the next arbitration phase. The fair arbitration algorithm only applies to host port SCSI IDs as defined by the assignment in each configuration.

CAUTION

Running the UltraSCSI Hub under heavy I/O with Fair Arbitration disabled may result in SCSI bus starvation for hosts with low IDs.

3.2Large Hub Addressing Configurations

The large UltraSCSI Hub has a specific SCSI ID configuration. The SCSI IDs are assigned to specific physical locations in the Hub. This allows the fair arbitration logic in the Hub to correctly identify the SCSI IDs that are participating in a fair arbitration cycle.

CAUTION

The SCSI ID of the HOST adapter must correspond to the assigned ID of the Hub port, to which the host port adapter is connected. Mismatched SCSI IDs will cause the SCSI bus to hang.

Figures 3-1 and 3-2 show the physical layout of the ports and their associated SCSI ID assignments on the DWZZH-S5 and DWZZH-09 Hubs.

3.2.1 Narrow Addressing Setting

The large Hub can be used with SCSI bus architectures that are limited to eight ID assignments such as Digital Unix 4.x and earlier versions (Figure 3-5 shows narrow ID assignments). A jumper on the rear of the Hub (Figure 3-6) must be installed to make the Hub respond to SCSI IDs 3 – 0 on the host ports. It should be noted that the DWZZH-09 Hub cannot be put into a narrow addressing mode.

3–2

EK–SMDZS–UG. B01

Page 22
Image 22
Compaq S5 manual Large Hub Addressing Configurations, Narrow Addressing Setting

S5 specifications

The Compaq S5, introduced in the mid-1990s, marked a notable entry in the realm of portable computing. This laptop was part of Compaq's efforts to deliver user-friendly, mobile computing solutions for both personal and professional environments. Combining functionality with compact design, the S5 quickly became popular among users seeking a reliable machine for everyday tasks.

One of the standout features of the Compaq S5 was its impressive portability. Weighing in at just around 5.3 pounds, the laptop was light enough to carry without much hassle, making it an ideal companion for on-the-go professionals. It boasted a slim profile that fit comfortably into most laptop bags, catering to those who valued mobility in their devices.

The S5 was equipped with a 10.4-inch passive matrix TFT display, offering a resolution of 640 x 480 pixels. While the display technology may seem modest by today’s standards, it provided decent visual clarity for the time, making it suitable for activities like document editing and basic multimedia viewing. With a maximum brightness of 80 nits, the screen could perform adequately in various lighting conditions, though it wasn't impervious to reflections.

In terms of performance, the Compaq S5 featured an Intel Pentium processor, delivering adequate speed for the software of the era, including word processing and simple graphic manipulations. The configurations typically included 8 to 16 MB of RAM and a hard drive ranging from 120 to 500 MB, which were quite acceptable for the applications common in the mid-90s.

The laptop ran on MS-DOS with Windows 3.1, allowing users to leverage the growing suite of software available for the platform. The integration of a floppy disk drive further complemented the machine's capability, facilitating easy file transfers and software installations, even as other storage technologies began emerging.

Connectivity options were limited by today's standards, but the Compaq S5 featured a modem port for dial-up connections, allowing users to connect to the internet through telephone lines. The laptop was also designed to support external peripherals through serial and parallel ports, providing some flexibility for additional functionality.

Battery life, an essential attribute for any portable device, was decent for the Compaq S5. It typically offered around 2 to 4 hours of usage on a single charge, depending on workload and settings. This made it viable for brief meetings or travel, although users often sought access to power outlets to extend their computing sessions.

In conclusion, the Compaq S5 represented a pivotal moment in portable computing during the 1990s. While it may not meet today's expectations for performance and features, it successfully tapped into the growing demand for mobile computing solutions and provided a reasonably powerful platform for that era.