=:The OpenVMS Frequently Asked Questions(FAQ)C

The OpenVMS Frequently Asked Questions(FAQ)



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14.43 Which DE500 variant works with which OpenVMS version?



HEnsure you have a version of the Alpha SRM console with support for the BDE500 series device. Apply ALL mandatory ECO kits for the OpenVMS Eversion in use, and also apply the CLUSIO, ALPBOOT, and ALPLAN kits, 8and apply any available ALPCPU ECO kit for the platform.



FTo check the DE500 device hardware id from OpenVMS, use the following command:

 

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$ ANALYZE/SYSTEM SDA> SHOW LAN/DEVICE=EWcu: 




$The "hardware id" will be displayed.

FTo set the DE500 speed via the Alpha SRM console environment variable:

 

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'   EWx0_MODE setting           Meaning @   --------------------------  -------------------------------- :   Twisted-Pair                10 Mbit/sec, nofull_duplex 8   Full Duplex, Twisted-Pair   10 Mbit/sec, full_duplex :   AUI                         10 Mbit/sec, nofull_duplex :   BNC                         10 Mbit/sec, nofull_duplex ;   Fast                        100 Mbit/sec, nofull_duplex 9   FastFD (Full Duplex)        100 Mbit/sec, full_duplex >   Auto-Negotiate              Negotiation with remote device 




.To override the console setting and use LANCP:

 

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$ RUN SYS$SYSTEM:LANCP  LANCP> SET DEV EWA0/SPEED=10 -LANCP> SET DEV EWA0/SPEED=100/full_duplex 




CFast Ethernet (100Base, 100 megabit) controllers such as the DE500 @series have a pair of connections available---while traditional DEthernet (10Base, 10 megabit) is inherently a half-duplex protocol, DFast Ethernet can be configured to use one or both of the available Dconnections, depending on the controller. Fast Ethernet can thus be <half- or full-duplex depending on the configuration and the Gcapabilities of the network controller and the Ethernet network plant. HSome Fast Ethernet controllers can also operate at traditional Ethernet Gspeeds, these controllers are thus often refered to as 10/100 Ethernet controllers.x

14.44 Third-party disk/tape/controllers/SCSI/widgets on OpenVMS?



FA wide variety of third-party widgets---SCSI and IDE disks and tapes, @graphics controllers, etc---are available for various platforms.

GIf you purchase third-party "generic" SCSI or IDE storage devices, you Cand your device vendor will be responsible for the testing and the Dsupport of the devices. In general, you can expect that Compaq will Gaddress non-standards-compliance problems within OpenVMS (changes that Bwill also not prevent operations with other supported devices, of <course), but you and/or the device vendor and/or the device Dmanufacturer are responsible for finding and fixing problems in the 9particular third-party device and or controller involved.

CIn particular, realize that neither SCSI nor IDE is a particularly @standard interface, these interfaces tend to be a collection of Goptionally-implemented and standardized interface features. You should Hnot and can not simply assume that all SCSI nor IDE storage devices are Finterchangeable. If you want to try to use a generic SCSI device, use FV6.2 or later, or (better) V7.1-2 or later. If you wish to try to use !IDE, use OpenVMS V7.1-2 or later.

kOn older OpenVMS releases, see the disk capacity limits ( Section 9.5).

DWith SCSI disks on releases prior to V6.2, ensure that you have the EARRE and ARWE settings configured correctly (disabled). (If not, you :will see DRVERR fatal drive errors and error log entries.)

BSome SCSI disks set the medium type byte as part of the SCSI size Efield---this is a SET CAPACITY extension to SCSI specs. This problem #also applies to VAX V7.1 and later.

EDisks with SCSI disk sizes past 8.58 GB and/or with the SET CAPACITY Eextension require ALPSCSI07 ECO or the OpenVMS Alpha V7.1-2 or later Srelease. (See Section 9.5 for further details.)

DBased on the displays of the (undocumented) SYS$ETC:SCSI_INFO tool; /this tool is present in OpenVMS V6.2 and later:

 

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F    Issuing 6-byte MODE SENSE QIOW to get current values for page 01h +           Page Code ................. 01h A           Page Name ................. Read-Write Error Recovery +           Saveable .................. Yes *           Size ...................... 10 ?           Hex Data .................. E6 08 50 00 00 00 08 00 -                                       00 00 




FThe E6 indicates that the AWRE and ARRE bits are set, and this is not Cacceptable on OpenVMS versions prior to V6.2. Further along in the #SCSI_INFO display, if you also see:

 

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I    Issuing 6-byte MODE SENSE QIOW to get changeable values for page 81h +           Page Code ................. 01h A           Page Name ................. Read-Write Error Recovery +           Saveable .................. Yes *           Size ...................... 10 ?           Hex Data .................. C0 08 50 00 00 00 08 00 -                                       00 00 




HThe C0 value means that the AWRE and ARRE values can be changed on this Gparticular SCSI device. (This is not always the case.) Use RZDISK from Gthe OpenVMS Freeware, and reset the E6 flag byte to hexadecimal 26 (or Awhatever the remaining mask when you remove bits C0) on page one.

@Each SCSI and IDE host contains non-trivial SCSI and IDE driver Csoftware, and each device contains equally non-trivial firmware--- Ctaken together with the mechanical and electronic components, this Hsoftware and firmware will determine whether or not a particular device will function as expected.

E Also note that various devices---such as various SCSI CD-R devices H ---can implement and can require vendor-specific protocol extensions, C and these extensions can require modifications to OpenVMS or the J addition of various utilities. In various of these cases, these devices G perform functions that will require them to use SCSI or IDE commands F that are (hopefully) architecturally-compatible SCSI or IDE command } extensions. (Also see Section 7.1 and Section 9.7.)

@In order for OpenVMS to officially support a particular device, Dintegration and testing work is mandated. There can be no certainty Fthat any particular device will operate as expected in any particular ?configuration without first performing this (non-trivial) work.

HIt is quite possible to find two devices---both entirely compliant with <applicable standards or interface documents---that will not interoperate.

AThe same general statement holds for OpenVMS bootstrapping on an Bunsupported VAX or Alpha platform. It might or might not work. In Fparticular, please see the OpenVMS Software Product Description (SPD) ?for the list of platforms supported by OpenVMS. OpenVMS is not Gsupported on the Personal Workstation -a series, on the Digital Server Cseries platforms, on the AlphaServer 2100 series 5/375 CPU, on the GMultia, on the AlphaServer DS20L, and on a variety of other platforms. D(You might or might not see success booting OpenVMS on any of these platforms.)R

14.44.1 Lists of third-party widgets on OpenVMS?



BVarious folks have successfully used common third-party disk disk Fdevices with OpenVMS, such as the IDE and SCSI variants of the Iomega Zip250 removable disk device.HCommon SCSI CD-R/CD-RW devices such as the Plextor PlexWriter 12/10/32S >SCSI series have also been successfully utilized with various FAlphaStation and VAXstation systems, and with tools such as CDRECORD. G(A Plextor burn of 614400000 bytes (300000 sectors) requires just over Esix minutes at 12x, using an AlphaStation XP1000 666 MHz EV67 system UltraSCSI host.)

EIf you choose to attempt to use third-party devices, ensure that you Hhave the current OpenVMS version and the current ECO kit(s) applied. In Hthe case of the IDE Zip250 drive, ensure that you have the most current #revision of SYS$DQDRIVER installed.Y

14.44.2 Are the 2X-KZPCA-AA and SN-KZPCA-AA LVD Ultra2 SCSI?

CYes. Both of these controllers are Ultra2 low-voltage differential (LVD) SCSI controllers.I

14.44.3 Resolving DRVERR fatal device error?



HIf this is on an OpenVMS version prior to V6.2, please see the AWRE and XARRE information included in section Section 14.44.n

14.45 How do I convert? Disk Blocks? KB, MB, GB, TB?



CThe granularity of disk storage allocation is called a disk block. GGroups of disk blocks are organized together into the smallest unit of Gstorage that can be allocated, and this unit is called a disk cluster. @The number of blocks in a cluster is the cluster factor, and is 0established when the disk volume is initialized.

DEach individual disk block is composed of five hundred twelve (512) Ebytes, or one-half kilobyte. Each byte is comprised of eight bits. A Fbit represents the smallest unit of information, typically refered to as a one or a zero.

EOpenVMS tends to uses base two notation for disk storage, while disk Estorage capacity specifications from most storage vendors (including -Compaq) will generally use base ten notation.

FAn OpenVMS disk block is 512 bytes in size; this is one-half kilobyte in base two notation.

DThe following table describes the prefix, the abbreviation, and the >associated base ten (marketing) and base two (OpenVMS) values.

 

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5            Base Ten                        Base Two C            -----------------------------   ---------------------- C  Kilobyte  (KB)  10**3              1000   2**10             1024 C  Megabyte  (MB)  10**6           1000000   2**20          1048576 C  Gigabyte  (GB)  10**9        1000000000   2**30       1073741824 C  Terabyte  (TB)  10**12    1000000000000   2**40    1099511627776 C  Petabyte  (PB)  10**15 1000000000000000   2**50 1125899906842624 




GThe base ten representation of the 2**40 value is 1099511627776, which Fis obviously rather ugly. When viewed as a base eight or base sixteen D(octal or hexadecimal, respectively) value, the value is far nicer. HSpecifically, the value is 10000000000 and 40000000 when represented in $octal and hexadecimal, respectively.

ENotational note: Within the OpenVMS FAQ, a Kilobit is represented by ;the appreviation Kb, while a Kilobyte is represented as KB.

ATo convert OpenVMS disk blocks to (base two) kilobytes (KB; 1024 >bytes), simply divide by two. To convert blocks to (base two) Gmegabytes, divide by 2048. Blocks to (base two) gigabytes (GB), divide Cby 2097152. These particular divisions can also be performed using Gbitshifts: to divide a value by two, shift the binary value rightwards by one bit position.

BTo convert OpenVMS disk blocks to (base ten) kilobytes, divide by approximately 1.953125.

CAnd for those rummaging around deep in SYSGEN, a microfortnight is approximately one second.c

14.46 Looking for connector wiring pinouts?



 

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;The DECconnect DEC-423 Modified Modular Jack (MMJ) pinout:    1: Data Terminal Ready (DTR)   2: Transmit (TXD)   3: Transmit Ground (TXD-)   4: Receive Ground (RXD-)   5: Receive (RXD)   6: Data Set Ready (DSR)     +------------------+    | 1  2  3  4  5  6 |    +------------+    ++                 +____+  




/The PC-compatible DB9 connector pinout follows:

 

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  1: Data Carrier Detect (DCD)   2: Received Data   3: Transmit Data   4: Data Terminal Ready (DTR)   5: Ground   6: Data Set Ready (DSR)   7: Request To Send (RTS)   8: Clear To Send   9: floating 




DThe MicroVAX DB9 console connector pinout predates the PC-style DB9 Epinout, and uses a then-common (older) standard pinout, and uses the *following EIA-232 series standard signals:

 

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  1: Protective Ground   2: Transmited Data   3: Received Data   4: Request To Send (RTS)   5: Data Terminal Ready (DTR)   6: Data Set Ready (DSR)   7: Signal Ground 9  8: Shorted to pin 9 on MicroVAX and VAXstation 2000... 4  9:    ...series systems, otherwise left floating.  F  When pin 8 is shorted to pin 9, this is a BCC08 (or variant) cable, A  most commonly used as a console cable on the MicroVAX 2000 and B  VAXstation 2000 series.  (Other systems may or may not tolerate   connecting pin 8 to pin 9.) 




>The BC16E-nn (where -nn indicates the cable length) cable key Aimpliicitly "flips over" (crosses-over) the signal wires, so all -DECconnect MMJ connectors are wired the same.

 

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     // .    ----                                 ---- .    |  |---------------------------------|  | .    ----                                 ---- .                                            \\




0The BC16-E-nn cross-over wiring looks like this:

 

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.        Terminal                         Host -        MMJ                              MMJ  9     DTR 1 --->---------->----------->--- 6 DSR 9     TXD 2 --->---------->----------->--- 5 RXD ,         3 ------------------------------ 4 ,         4 ------------------------------ 3 9     RXD 5 ---<----------<-----------<--- 2 TXD 9     DSR 6 ---<----------<-----------<--- 1 DTR 




The BN24H looks like this:

 

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     MMJ       RJ45        1---------8       2---------2       3---------1       4---------3       5---------6       6---------7 




The BN24J looks like this:

 

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     MMJ       RJ45        1---------7       2---------6       3---------3       4---------1       5---------2       6---------8 




Also see:

p

14.47 What connectors and wiring adapters are available?



?The H8571-B converts the (non-2000-series) MicroVAX DB9 to MMJ CDECconnect. The MicroVAX 2000 and VAXstation 2000 requires a BCC08 lcable (which has the 8-9 short, see Section 14.46) and the H8571-D for use with DECconnect.

HMore recent HP (HP, Compaq or DIGITAL logo) systems will use either the <DECconnect MMJ wiring or (on all recent system designs) the PC-compatible DB9 pinout.

DECconnect MMJ adapters:

 

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4    Part:      Converts BC16E MMJ male to fit into:  3    H8571-C  25 pin DSUB Female to MMJ, Unfiltered .    H8571-D  EIA232 25 pin male (modem-wired) 1    H8571-E  25 pin DSUB Female to MMJ, Filtered /    H8571-J  PC/AT 9 pin male (PC serial port) 4    H8572-0  BC16E MMJ double-female (MMJ extender) +    H8575-A  EIA232 25 pin female (common) 5    H8575-B  EIA232 9 pin male (MicroVAX II console) 4    H8575-D  25 Pin to MMJ W/EOS and ESD Protection *    H8577-AA 6 pin Female MMJ to 8 pin MJ 5    BC16E-** MMJ cable, available in various lengths 




ENumerous additional adapters and cables are available from the _OPEN DDECconnect Building Wiring Components and Applications Catalog_, as /well as descriptions of the above-listed parts.

BThe H8571-A and H8575-A are MMJ to DB25 (female) and are wired as follows:

Also see:



GJameco offers a USB-A to PS/2 Mini DIN 6 Adapter (as part 168751), for =those folks wishing to (try to) use PS/2 Keyboards via USB-A connections.h

14.48 What is flow control and how does it work?



%XON/XOFF is one kind of flow control.

DIn ASCII, XON is the [CTRL/Q] character, and XOFF is the [CTRL/S].

GXON/XOFF flow control is typically associated with asynchronous serial Gline communications. XON/XOFF is an in-band flow control, meaning that +the flow control is mixed in with the data.

ACTS/RTS is another type of flow control, and is sometimes called Ghardware flow control. Out-of-band means that seperate lines/pins from <the data lines (pins) are used to carry the CTS/RTS signals.

HBoth kinds of flow control are triggered when a threshold is reached in >the incoming buffer. The flow control is suppose to reach the Etransmitter in time to have it stop transmitting before the receiver Ebuffer is full and data is lost. Later, after a sufficient amount of Ethe receiver's buffer is freed up, the resume flow control signal is (sent to get the transmitter going again.

GDECnet Phase IV on OpenVMS VAX supports the use of asynchronous serial Acommunications as a network line. The communication devices (eg. Gmodems, and drivers) must not be configured for XON/XOFF flow Econtrol. The incidence of these (unexpected) in-band characters will Dcorrupt data packets. Further, the serial line device drivers might @normally remove the XON and XOFF characters from the stream for @terminal applications, but DECnet configures the driver to pass Dall characters through and requires that all characters be Epermitted. (The communication devices must pass through not only the @XON and XOFF characters, they must pass all characters Eincluding the 8-bit characters. If data compression is happening, it Hmust reproduce the source stream exactly. No addition or elimination of ,null characters, and full data transparency.

DAn Ethernet network is rather different than an asynchronous serial Fline. Ethernet specifies the control of data flow on a shared segment Gusing CSMA/CD (Carrier Sense Multiple Access, with Collision Detect) AnGEthernet station that is ready to transmit listens for a clear channel B(Carrier Sense). When the channel is clear, the station begins to Gtransmit by asserting a carrier and encoding the packet appropriately. BThe station concurrently listens to its own signal, to permit the Cstation to detect if another station began to transmit at the same Gtime---this is called collision detection. (The collision corrupts the Csignal in a way that can reliably be detected.) Upon detecting the Gcollision, both stations will stop transmitting, and will back off and Etry again a little later. (You can see a log of this activity in the DECnet NCP network counters.)

HDECnet provides its own flow control, above and beyond the flow control ?of the physical layer (if any). The end nodes handshake at the Gbeginning to establish a transmit window size---and a transmitter will <only send that much data before stopping and waiting for an Hacknowledgement. The acknowledgement is only sent when the receiver has Cconfirmed the packet is valid. (A well-configured DECnet generally Gavoids triggering any underlying (out-of-band) flow control mechanism.)




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