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The LavaPort-650 uses a 16650 UART incorporating a 32-byte FIFO (first-
in first-out) buffer.

The FIFO control tabs set the buffer “trigger” levels. When the buffer is
filled to its trigger level with the selected number of bytes, the CPU will
be interrupted and asked to either reload the buffer (for transmission),
or retrieve data from the buffer (for reception).

Most efficient data transmission occurs when the CPU is interrupted
infrequently. For each interrupt, the CPU can then service the buffer with
larger data blocks: during transmission, it can place a large burst of data
into the buffer, and during reception it can retrieve a large block from
the buffer and then continue multi-tasking.

Ideally therefore, Receive triggers should be set as high as possible and
Transmit triggers as low as possible.

However, if the Transmit trigger levels are set too low, or Receive triggers
too high, and the CPU is busy when an interrupt is called by the
LavaPort, a short period of inactivity may occur between the port and
the modem. This will reduce effective transmission/reception speeds.

Optimum buffer settings are dependent on your modem speed, your
CPU speed, and the amount of multi-tasking that occurs while online.
For a fast modem and fast CPU performing few multi-tasking functions,
set transmit triggers low and receive triggers high. If multi-tasking while
online, set transmit triggers higher and receive triggers lower.

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Summary of Contents for LavaPort 650

Page 1: ...LavaPort 650 Installation Manual Rev B01 LAVA COMPUTERS SSERIAL PCI P N MOKO L74 1 MADE IN CANADA PN MOKO S 1 MADE IN JAPAN 0255351 ...

Page 2: ...Com IRQ Setting LavaPort Data Rates Lava Modem Speed Set for 230 4 kbps Setting LavaPort FIFO Control Flow Control Windows NT 4 0 Installation High Speed Data Rates 3 4 5 8 10 12 14 16 17 18 Note Instructions for installing the LavaPort 650 under DOS or Windows 3 x may be found at http www lavalink com 2 ...

Page 3: ...ager Ports The LavaPort 650 port will be listed as one of your Com Ports Click Properties to change the default settings as desired 5a For Windows 95 98 ME install the Lava Com Port Redirect and Lava Modem Speed Set utilities to change the Com numbers of your ports and to automate modem speed settings 5b For Windows 2000 XP you can redirect your Com ports by Right Clicking My Computer Properties H...

Page 4: ...used PCI slot and insert the LavaPort 650 into it Ensure that it is well seated 3 Screw the metal backplane of the LavaPort 650 board to your PC s casing and replace the machine s cover 4 Connect your modem cable to the LavaPort 650 port and turn the PC on PCI Slot Port Screw for attaching card bracket to PC casing ...

Page 5: ...this disk 2 After the necessary files have been copied Windows will complete the full installation of the LavaPort 650 During this process a new Com Port will be created in Device Manager under the Ports tree The following describes how you may customize this port for your personal needs Windows Installation Note Note Make sure that you are installing the correct LavaPort 650 drivers for the appro...

Page 6: ...6 3 Click on the Start button then choose Settings Control Panel System Device Manager You should see a window that is similar to the following ...

Page 7: ...4 Click on Ports and select the Com port listed under the heading LavaPort 650 PCI 5 Click Properties The following screen will appear 7 ...

Page 8: ... 5 even though any one of Com1 4 may be free If your software requires the use of standard I O resources you may modify those used by the LavaPort 650 in one of two ways Click on the Resources Tab in the LavaPort 650 listing in Device Manager A screen similar to the following will appear Modifying the Com numbering and IRQ of your Port ...

Page 9: ...ive To install the Lava Port Redirect utility on your hard drive insert the LavaPort diskette into your floppy drive click Start Run and type A Utils Setup The Lava Port Redirect Utility will allow you to change the Com number assigned to the LavaPort 650 e g Change Com5 to Com 4 without modifying I O resources 2b For Windows2000 XP you can change port numbers by Right Clicking My Computer Propert...

Page 10: ...10 Setting LavaPort Data Rates in Windows ...

Page 11: ... Up Networking are controlled independently of speed settings in Device Manager For optimum performance always verify that your LavaPort is set to the maximum speed supported by your modem and that all speed settings are the same in every application Please note that the setting of Communications Port Data Rates is often the most confusing of tasks encountered by modem users For this reason Lava h...

Page 12: ...equire special settings AT Commands and INF files for configuration Lava has included a software utility called Lava Modem Speed Set which automates these functions and allows for easy speed reconfiguration This utility may be found in the Utils subdirectory of your LavaPort diskette and is constantly being updated to support more modems Please check the Lava Web site for details www lavalink com ...

Page 13: ...13 ...

Page 14: ...14 Setting LavaPort FIFO Control in Windows ...

Page 15: ...n it can retrieve a large block from the buffer and then continue multi tasking Ideally therefore Receive triggers should be set as high as possible and Transmit triggers as low as possible However if the Transmit trigger levels are set too low or Receive triggers too high and the CPU is busy when an interrupt is called by the LavaPort a short period of inactivity may occur between the port and th...

Page 16: ...ng the LavaPort to a modem or ISDN terminal adapter use the default setting of Hardware RTS CTS flow control Software Flow Control Xon Xoff is used only for connecting the LavaPort to a non modem serial device e g Using a null modem cable to connect to another Com Port 16 Setting LavaPort Flow Control in Windows ...

Page 17: ...Start Menu When prompted type A NT4 0 Setup 3 After the necessary files have been copied select My Computer and start Control Panel A new icon will appear called LavaPort This applet should now be used to configure ALL Com Ports in your PC not just LavaPorts Note Make sure that you are installing the correct LavaPort 650 drivers for the appropriate operating system DO NOT install Windows 3 x 95 98...

Page 18: ... rates above 115 2 kbps If your modem does not support higher data rates and you select a higher data rate in the LavaPort Properties Windows will automatically default to the slowest supported rate in the chain Some modems do support higher data rates but require special settings AT Commands and setup files for configuration Contact your modem manufacturer or check www lavalink com for details Se...

Page 19: ...19 This page intentionally blank ...

Page 20: ...et www lavalink com This device complies with part 15 of the FCC Rules Operation is subject to the following conditions 1 This device may not cause harmful interference and 2 this device must accept any interference received including interference that may cause undesired operation Lava Computer MFG Inc 908 Niagara Falls Blvd 629 North Tonawanda NY 14120 2060 ...

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