The latest news from ALCS

ALCS Version 2 Release 4 available

ALCS 2.4 is now available. The recommended way to receive the product is via eDelivery. Refer to "Downloading full product versions" for more information.

Alternatively, your local IBM representative can order a product CD from the IBM distribution centre in Boulder, USA through the normal IBM internal tools for product configuration and ordering.

The ALCS 2.4 manuals are available for viewing and download in pdf format from the Library Section of this website. When the online library versions become available we will add a link to them.

ALCS Version 2 Release 4 announced

ALCS V2.4 was announced on the 20th May 2008 with a planned availability date of 13th June 2008. We will be updating this site with more information in due course. For the time being here is a brief description of the new release:

A currently supported release of z/OS is prerequisite for ALCS V2.4. At present that is z/OS 1.7 or above.

Airline Control System (ALCS) V2.4 is designed with the following new facilities and enhancements:

• Exploits virtual storage above 2 GB
• Option to move VFA above 2 GB
• Support for large IP messages
• Optimizes MQ Bridge moving it from ECB controlled code to the ALCS monitor
• Provides the ability to display TCP/IP Trace online
• Enhances the display of load module status
• Allows an application to check availability of a given pool
• Option for filing stamps to be application rather than TPFDF program names
• Allows an installation-wide monitor exit to determine whether storage belongs to an Entry
• Adds program version to duplicate dump table
• Implements the performance monitor throttle facility
• Assists in detecting and reducing high message rates from programmed operators
• All enhancements shipped as program temporary fixes (PTFs) since the release of ALCS V2.3.1 have been consolidated in V2.4.

ALCS Hiper APAR issued

ALCS may not close an out-of-date copy of the CDS which has been offline before an ALCS restart. This can result in ALCS restart building an online table that does not match the most recent database configuration.

For example, a copy of the CDS is varied offline and then a ZDASD LOAD is performed which increases the size of the database. If the offline CDS is not renamed then any ALCS restart may attempt to open that CDS. In some such cases this CDS could be the one used to build the online DASD tables. The inconsistency could result in ALCS failing during or shortly after restart.

ALCS has been modified to correctly check for an out of date CDS at restart and close it.

For ALCS 2.3.1 apply the corrective APAR AK45940 (PTF UK33413).

Cumulative Maintenance available

We have placed Maintenance Update Transfer 4 under the Maintenance Section of this website.

In the past we have distributed cumulative maintenance on tape (3480). This has problems. The tapes have been rejected by some countries' customs authorities. Not all customers can utilise 3480 cartridges and for us to export physical media is more burdensome than it was previously due to export regulations.

To overcome this, ALCS cumulative maintenance will, from now on, be delivered via this website. MUT 4 (Maintenance Update Transfer 4) is now available for downloading. It is a zipped file, less than 2MB in size, that expands to 7.5MB. Login to the ALCS maintenance server to enable the download.

In addition we have added the 3 previous maintenance tapes in the same maintenance transfer format.

Latest manuals available

We have placed the September 2007 editions of the ALCS 2.3.1 manuals under the Library Section of this website.

The manuals are available for viewing and download in pdf format. There is also the hyperlink to the bookmanager version of the manuals which has been updated to point to the bookshelf with the latest manuals.

ALCS has a new home and Product Manager

We are pleased to announce that ALCS is moving from the IBM Hursley Lab in the UK to become part of the TPF Lab in IBM Poughkeepsie, USA. Making ALCS part of the TPF Lab will be of long term benefit to the product and its users as more management, development and support resources for airline transactions systems are available in the TPF Lab. From the current ALCS team, Ann Evans, Nico Wigmans and Mike Hannaford will remain with the product.

We give our thanks to Helen Pinchin, Steve Walker and Vanessa Dougan who will be handing over their roles in the coming months to the TPF Lab. We will miss them and offer good wishes to them in their future IBM careers beyond ALCS.

We welcome on board Jim Bodoh, Tony Cresswell and Stephen Record to ALCS Development and Support. Dan Jacobs, a TPF project manager, has been appointed to take on the role ALCS project manager; Al Brajnikoff will be handling Information Development. Also supporting the product will be Carol Carson, Rick Collins and Don Flinchum in IBM Raleigh, USA who will be providing build and release support.

We will endeavor to make the transition as smooth as possible, support will remain at alcs@uk.ibm.com and our website will stay at http://www.ibm.com/tpf/alcs.

Kevin Barnes has been appointed ALCS Product Manager, taking over from Helen Pinchin. Kevin has been a manager, in the TPF Lab, for 5 years. He reports directly to Theresa Dryfoos, the TPF Development Lab Manager. Kevin can be contacted via his e-mail address, kevinb@us.ibm.com, and his telephone number is +1 845 433 2660.

Holiday Weekend

Monday May 28th is a UK, US and Dutch national holiday. None of the ALCS Support staff will attend work on this day.

Please refer to the Emergency Support Procedure to contact us in an emergency during this three day weekend.

ALCS Performance Monitor

The ALCS Performance Monitor is available (APARs AK33864 (PTF UK24579) and AK34228 (PTF UK24599)). This satisfies ALCS User Group requirement ATC0262, which asked for the Performance Monitor developed by Jorge Widmar to be incorporated into ALCS.

  Click here for further details on the ALCS Performance Monitor.

Season's Greetings

We would like to wish all our customers the warmest greetings for the festive season ahead.

During the period from Friday December 22nd through Tuesday January 2nd we will be attending to critical problems sent to alcs@uk.ibm.com. However other problems, and questions, may be deferred for attention until after those dates.

Dec 25, Dec 26 and Jan 1 are UK national holidays. Please refer to the Emergency Support Procedure to contact us in an emergency during these holidays.

TPFDF PUT21 available

The general availability (GA) of TPFDF 1.1.3 PUT 21 was announced on June 30, 2006.

PUT 21 uses features unique to ALCS 2.3.1 and is not applicable to users of ALCS 2.2.1. ALCS 2.2.1 is being withdrawn from service on December 31st, 2006

The unpacking instructions are provided in the Memo to Licensees.

  Click here for the TPFDF PUT21 Memo to Licensees.

ALCS Education Oct 2006

We will be running two ALCS V2.3.1 classes at Hursley, in the UK, during 2006. The classes are scheduled for the weeks of 9th and 16th October 2006. There will be no charge for attending these classes. To secure places, we recommend ALCS customers enrol their programmers as soon as possible. The number of places per ALCS customer may be limited if the classes are over subscribed, those booking first will be favoured. The two classes are:

ALCS Concepts and Applications Class - Monday 9 October to Friday 13 October

ALCS System Programming Class - Monday 16 October to Friday 20 October

All enrollments for these classes must be sent to alcs@uk.ibm.com.
If insufficient enrollments are received, one or both of these classes will be cancelled.

Recent APAR AK18060

New note on APAR AQ94450 / PTF UK07955

Application of this fix has resulted in problems for customers client systems software.

One of the items this APAR/PTF corrects is the conversion of the ALC Line number (CM1LNA) on TCP/IP output messages to be translated using translate table LINEALC.

Before the update the field, CM1LNA, was not translated. Please ensure you test with this APAR/PTF for such incompatibilities with client software and resolve them before promoting this fix.

Change in APAR/PTF packaging format

Maintenance files, such as APARs, PTFs and the maintenance lists that were formerly built as self extracting zip files will from January 2006 will be built as plain zip files. The file extension will be .ZIP rather than .EXE on these files.

Users will be required to unpack the files using a unzip utility. This change is due to a change in licence that IBM has with it's zip software supplier.

ALCS 2.3.1 Hiper APAR issued

APAR AQ85388 (PTF UK08892) added a routine in ALCS to monitor the interface between ALCS and MQSeries. In some conditions, this routine can generate a fixed point divide exception. This can result in a CTL-000001 system error causing ALCS to fail.                                                                     

If you apply APAR AQ85388 (PTF UK08892) to ALCS, and you intend to use the MQSeries support, then you must also apply APAR AK17764 (PTF12083).                                

Using LookAt to lookup message explanations

LookAt is an online facility that lets you look up explanations for most of the IBM messages you encounter, as well as some system abends and codes. Using LookAt to find information is faster than a conventional search because in most cases LookAt goes directly to the message explanation.

You can use LookAt from the following locations:

• The Internet.
  You can access IBM message explanations directly from the LookAt Web Site. Click here.
• Your z/OS TSO/E host system.
  You can install code on your z/OS systems to access IBM message explanations, using LookAt from a TSO/E command line.
• Your Microsoft Windows workstation.
  You can install code to access IBM message explanations on the z/OS Collection (SK3T-4269), using LookAt from a Microsoft Windows command prompt (also known as the DOS command line).
• Your wireless handheld device.
  You can use the LookAt Mobile Edition with a handheld device that has wireless access and an Internet browser. Link to the LookAt Mobile Edition from the LookAt Web site.

You can obtain code to install LookAt on your host system or Microsoft Windows workstation from a disk on your z/OS Collection (SK3T-4269), or from the LookAt Web Site (click Download, and select the platform, release, collection, and location that suit your needs). More information is available in the LOOKAT.ME files available during the download process.

New Requirements - Submit them now

It is now time start the requirements process again.

The first step requires your organisation to submit to us any new ALCS requirements that you have. Please use this ALCS User Group Requirement Request Form to submit your new requirements. Download the form, update it and then return it to us at alcs@uk.ibm.com. Alternatively, just cut and paste the form directly into a note.

The ALCS User Group Requirement Request Form contains guidance on how each section of the form should be completed. Please provide as much information as possible on the form as this will help us when we are reviewing your requirement. Please submit your new requirements to us as soon as you can. Those requirements submitted by the 31st December 2006 will be included in the next round of voting. If you wish to verify whether a specific user requirement has already been submitted, please check the recently updated ALCS User Group Requirements List.

If you have any questions or comments about the process or would like to discuss any items, new or old, then please send a note to us at alcs@uk.ibm.com.

ALCS on z/OS 1.7 (and future z/OS releases)

In z/OS 1.7 a change in the DF SMS area that ALCS uses to access the real time database has resulted in new APARs that are required for ALCS 2.3.1 and ALCS 2.2.1 to run on these releases. Please apply APAR AK12959 (PTF UK09810) to ALCS 2.3.1 and APAR AK12963 (PTF UK10112) to ALCS 2.2.1 before migrating to z/OS 1.7.

ALCS 2.2.1 Withdrawal from Service Notice

The ALCS Release V2.2.1 is to be withdrawn from service on December 31st, 2006. This was publicised in the recent z/OS Withdrawal Announcement 905-180.

Those customers, who have not done so, should plan to move to the replacement product ALCS V2.3.1 which became available in December 2003. If you require any information or assistance with planning the move to the latest release then please contact us.

ALCS 2.3.1 Hiper APAR issued

APAR AK08549 (PTF UK07133) adds logic to avoid database corruption that can occur when adding new real-time data sets. Datasets are added by ZDASD LOAD when the VOLUMES= parameter on DBSPACE has been specified in the database generation. ALCS allocates new "dispense pointers" in memory (there is one dispense pointer record for every 24 data sets). Without this fix it is possible for ALCS to keypoint the new dispense pointer data before allocating a record for it. If this happens, ALCS will file the first L3 allocatable pool record (ordinal zero), overwriting it with the new dispense pointer data, corrupting the existing data in that record.

ALCS Hiper APARs issued

A problem has been found with a previous enhancement to the sequential file DCB SYNAD exit routine. APAR AQ56304, issued 3 years ago, added support for sequential file buffers above 16Mb. It updated the DCB SYNAD exit for support of 24 and 31 bit callers. If this routine is called it can result in a CTL-1 and if the sequential file concerned is the log file then a CTL-1A catastrophic error will follow. To prevent such a possible scenario please apply the following.

For ALCS 2.2.1 apply the corrective APAR AK06321.

For ALCS 2.3.1 apply the corrective APAR AK06318 (PTF UK06271).

ALCS Software Product Survey 2005 results

Many thanks to all of you who took the time to complete the ALCS survey for us. If you were unable to attend the recent ALCS User Group in New Zealand here are the results that were presented:

2005 Survey Results

APAR prefixes are changing

Effective March 2005, the prefixes of APAR numbers have changed from AQ to AK because the available APAR numbers have been depleted. Please review your automation dependencies to determine if you will be impacted by this change.

If you have any questions or concerns about the information in this service bulletin, send an e-mail to alcs@uk.ibm.com

Looking back and looking ahead

Happy New Year. We hope all our customers have a successful 2005.

ALCS 2.3.1

We now have six customers that have migrated their production systems to ALCS 2.3.1. The migration has been straight forward for these customers with no on-site assistance required.

We would urge those customers who have not started the planning for the migration to consider this as a task for this year.

Along with the new facilities announced in ALCS 2.3.1, additional new functions have been added through the maintenance program including the following User Group requirements :

Your requirements please

We are looking at our plans for the year ahead, and would like to ensure that ALCS includes the functionality that you, our customers, need. The main way we get to know what you need is through the User Group Requirements and we recently sent out a request asking you submit any new requirements. Please could we urge you to give a lot of thought to this. We're happy to take on plenty of new development work!

Steve Walker joins ALCS Team

Many of you will know that Tony Shortman retired during 2004 after a long career with us. Whilst we will miss him, we are very pleased to say we have a new member in our team who comes with a wealth of TPF/ALCS experience. Steve Walker joined us in December having formerly worked both at various TPF/ALCS customer sites and within IBM Software Group.

ALCS on z/OS 1.5 and later releases

In z/OS 1.5 and later releases a change in the DF/SMS area that ALCS uses to access the real time database has resulted in new APARs that are required for ALCS 2.3.1 and ALCS 2.2.1 to run on these releases. Please apply APAR AQ96210 (PTF UK00504) to ALCS 2.3.1 and APAR AQ96928 (PTF UK00531) to ALCS 2.2.1 before migrating to the latest z/OS releases.

ALCS Hiper APARs issued

A problem has been found with the COMGEN RCVSZEIP=MAX support. There are circumstances in which the buffer obtained by ALCS for the input message is not large enough which can result in ALCS table corruption. This can lead to unpredictable results such as an ALCS loop or catastrophic error.

If you are using or plan to use the COMGEN RCVSZEIP=MAX support (introduced with PTF UQ67134 in ALCS 2.2.1 and shipped in the base ALCS 2.3.1 product) you must apply the following corrective maintenance.

For ALCS 2.2.1 apply the corrective APAR AQ92880 (PTF UQ93442).

For ALCS 2.3.1 apply the corrective APAR AQ92876 (PTF UQ92897).

ALCS 2.3.1 Hiper APAR issued

APAR AQ92565 (PTF UQ92896) adds logic to avoid a CTL-000001 in DXCOCTM during ALCS restart.

Users of OCTM may define CRI ranges to be reserved for non OCTM devices, in the ALCS communication generation. If ranges such as aa0001-bbcccc are defined a CTL-000001 during OCTM restart may occur. This is because the area used to build the CRI ranges may be used by another routine as a register save area.

As the symptom for this problem is a restart failure the APAR is marked HIPER.

IPCS REXX execs for ALCS

Item updated 07 Jul 2004. The 2.3.1 execs have been updated to support ECBs quarantined by ZPURG FORCE (AQ87977).

ALCS 2.2.1 PTF UQ64211 added the ability to request an SVC dump when an ALCS catastrophic error occurs. This support is included in ALCS 2.3.1. To view such dumps the MVS tool used is IPCS, for which, REXX execs can be written to format areas of storage. We have developed some IPCS REXX execs which may be used and we provide them here on an 'as is' basis. If you would like to try the execs then please download the files from the following two links.

For the IPCS 2.3.1 execs click here and for the documentation  click here

For the IPCS 2.2.1 execs click here and for the documentation  click here

The execs are not rigorous and may require tailoring for your installation. Please contact us at alcs@uk.ibm.com for assistance or to request a new exec to do additional formatting.

First site to migrate to ALCS 2.3.1

On April 18th, Carina, the Air New Zealand reservation system managed by IBM Global Services successfully migrated from ALCS 2.2.1 to ALCS 2.3.1. Our congratulations to all those involved.

OCTM User guide and Sample application

One of the new functions in ALCS 2.3.1 is the Online Communication Table Maintenance. OCTM is a system facility that provides an api (COMTC) through which an end user system can alter the communication definitions. Information on OCTM along with a description of a sample application are described in a manual available below.

Update 18th March 2004. The OCTM facility has been enhanced with an offline OCTM support program plus an updated OCTM User Guide. APARs AQ80877 and AQ80878 provide this new offline program. If you are planning to use OCTM and to develop a CEUS, we recommend that you apply these APARs and download the updated OCTM User Guide, below. The updated Guide contains information on running the new offline program.

For the sample EUS click here and for the OCTM User Guide  click here

Requirements List Updated

The User Group Requirements List has been updated to reflect changes in items delivered and new submissions requested. We have removed older satisfied requirements to make the list more readable. Requirements that were shipped by the end of 2000 are no longer on the list, as seen on the website.

If you wish to raise a new requirement then please send it to us alcs@uk.ibm.com or to the User Group chairman.

ALCS 2.3.1 manuals available

We have placed the new ALCS 2.3.1 manuals, in PDF format, under the Library Section of this website.

These manuals cover the new facilities available in ALCS 2.3.1 and all developments that took place in ALCS 2.2.1 including DECB and the MQSeries Bridge.

The manuals are available for viewing and download in pdf format. Links will be made available for viewing the bookmanager version of the manuals shortly. The bookmanager and pdf manuals are the same. Only the viewing format is different.

ALCS User Group Dates

The date of the next ALCS User Group meeting has been announced by the user group chairman, Rob Broere. It will be a 3-day meeting commencing on Tuesday 3 February 2004, and will be hosted by EVA Air in Taiwan.

It has been over 12 months since the last user group meeting, and during that time there have been important changes taking place. One of these has been the development of the new ALCS release that we have recently announced.

We would encourage you to attend the next user group meeting in February so that you can obtain a detailed briefing on the content of the new ALCS V2.3.1 release. We look forward to seeing you at that meeting.

ALCS Version 2 Release 3.1 announced

ALCS V2.3.1 was announced on the 11th November 2003 with a planned availability date of 12th December 2003. We will be updating this site with more information in due course. For the time being here is a brief description of the new release:

ALCS V2.3.1 will be the base for exploiting the new 64-bit addressing functions of the operating system. OS/390 2.10 or z/OS is a prerequisite for ALCS V2.3.1.

All enhancements shipped as program temporary fixes (PTFs) since the release of ALCS V2.2.1 have been consolidated in V2.3.1.

The new release, has the following new facilities and enhancements:

• Real storage above 2 GB, 64-bit addressing

  The availability of 64-bit addressing allows ALCS to use real memory above 2 GB, thus removing memory constraints and freeing memory for the use by applications and other subsystems.

• Online Communications Table Maintenance (OCTM)

  This facility provides dynamic reconfiguration of the communications network and eliminates communications table consolidations.

• System takeover facility

  The system takeover facility allows for a hot ALCS standby system, which significantly reduces the time required for planned and unplanned switchovers.

• E-mail queue handler

  The e-mail queue handler manages the queueing of outbound messages, while the path to the remote destination is unavailable.

• Multiple TCP/IP listeners

  This facility allows the use of multiple ports for the simultaneous reception of transactions by multiple TCP/IP applications.

• Virtual IP addressing (VIPA)

  This facility makes TCP/IP applications independent of physical Internal Protocol (IP) addresses, improving the ease of system management.

• Long-term pool monitoring enhancement

  This enhancement provides more accurate control over the use of long-term file pools.

ALCS Classes - Now Rescheduled

We have rescheduled the two ALCS classes that were originally going to be run in May this year.
The new dates for the classes are:

ALCS Concepts and Applications Class - Monday 8 December 2003 to Friday 12 December 2003

ALCS System Programming Class - Monday 16 February 2004 to Friday 20 February 2004

There will be no charge for attending these classes.
Although we already have ALCS customers enrolled on both classes, there are still a number of places available.If you would like to attend either or both of these classes, please send your enrollment request to alcs@uk.ibm.com.
The number of places per ALCS customer may be limited if the classes are over subscribed; those booking first will be favoured.
Both classes will remain open for enrollments until two weeks prior to the commencement of the class (or will close for enrollments if the class becomes full).

The ALCS Concepts and Applications Class starts at 13.00 on Monday and ends at 12.00 on Friday.
The ALCS System Programming Class starts at 9.30 on Monday morning and ends at 17.00 on Friday.

Update to AQ65812 - Comgen required

This APAR requires that a Communication generation is run if you have MQ communication definitions otherwise MQ queue names in the communication table may be lost.

The APAR alters the CO0IN DSECT which is a macro that describes the format of the data that is output from the Communications generation step and is input to the online initialisation phase. For resources defined as COMDEF LDTYPE=MQ there are fields in CO0IN for three 48-byte queue names:-

LE update for multi-TCB ALCS

APAR AQ76823 ensures that ALCS always honours the virtual storage location specified on storage requests from Language Environment (LE).

The original error that prompted this APAR was a storage leak found on multiple TCB ALCS systems. The leak is due to LE requesting storage directly from MVS with TCB affinity rather than requesting the storage through the ALCS LE service routine. This issue was addressed by LE APAR PQ76054. Since creating an APAR on a current release of LE could affect other users, LE have developed LE USERMODs which are available for ALCS customers on OS/390 2.10 through z/OS 1.5.

If your installation runs the C/C++ utility components of TPFDF, or any other C/C++ programs, in a multiple TCB ALCS environment, then you will need to apply the LE USERMOD as well as this ALCS APAR. Please contact ALCS Technical Support at alcs@uk.ibm.com to obtain the relevant LE USERMOD.

ALCS Timing Changes

APAR AQ72639 changes the timing values used by the ALCS entry dispatcher for servicing the defer list (for DEFRC and DLAYC macros). It also increases the maximum time that an entry is allowed to execute before it must lose control (the application loop timeout value).

The frequency at which the ALCS entry dispatcher processes the defer list has always been set at 0.2 seconds, but over recent years the IBM processors upon which ALCS runs have become much faster and this frequency is no longer appropriate for the current IBM hardware.

After applying this APAR, the frequency at which the ALCS entry dispatcher processes the defer list will be 0.05 seconds. This change may impact ALCS applications that issue large numbers of DEFRC or DLAYC macros and large numbers of database read/writes.

The number of instructions that an entry is allowed to execute before it must lose control (the application loop timeout value) has remain unchanged in ALCS for many years. Because of the increased performance of IBM processors in recent years, the current timeout value needs increasing.

After applying this APAR, the timeout value for application loop timeout will be four times greater than the current value. If you have user modifications that increase the timeout value, these should be carefully reviewed. We recommend that user modifications to the timeout value are not reapplied to your ALCS system. Please run your ALCS system with the new timeout value to determine if it is suitable for your application requirements.

ALCS Web Site passwords

Passwords that are used to access restricted areas of the ALCS Web site are being changed on Tuesday, May 27, 2003. New passwords will be provided a few days before the change. Existing passwords will be accepted until May 27. Company user IDs will not be changed.

If you have any questions, send an e-mail to alcs@uk.ibm.com.

ALCS Web Site has moved

The URL for our main ALCS web page has changed from

As you can see the change is from "ts" to "htp." The "ts" stands for "transaction systems" and the "htp" stands for "host transaction processing." This aligns the ALCS Web address with the other host products for IBM transaction processing.

This transistion should be tranparent to you as redirects have been set up to point the old URLs to the new ones, and these will exist for quite a while.

However, in time they may go, so if you have any Bookmarks or programs/procedures which use any of the ALCS web page addresses then please update them to the new address. This will improve performance as it will bypass the redirect.

Managing the User Group Requirements

At the last ALCS User Group meeting in The Netherlands, IBM was asked to take responsibility for managing the ALCS User Group Requirements list. We have therefore conducted a detailed review of the complete user group requirements process with the User Group Chairman and would like to recommend to the ALCS User Group a new procedure for managing the requirements list.

We would also like to recommend changes in the requirements voting procedure. The primary recommendation is to set a maximum limit on the number of votes each ALCS customer can cast for just one requirement.

The following document describes these recommendations.

  ALCS User Group Requirements Process - Draft Proposal

Latest Manuals available

We have placed the latest issues of the ALCS manuals under the Library Section of this website.

These manuals cover new facilities in ALCS including DECB and the MQSeries Bridge.

The manuals are available for viewing and download in pdf format. There is also the hyperlink to the bookmanager version of the manuals. This link has been updated to take you to the latest ALCS bookshelf on the OS/390 Collection CD. The bookmanager and pdf manuals are the same. Only the viewing format is different.

Maintenance Update Tape 7 shipped

We have recently sent to each ALCS customer a 3480 cartridge tape labelled DXC007. This tape contains all ALCS V2.2.1 and IPARS V2.2.1 PTFs issued from June 2002 through to December 31st 2002. Accompanying the tape is the usual documentation. The tape is sent via conventional mail and may take some time to reach some of you. If you do not receive the tape in the next few weeks please let us know by sending a note to alcs@uk.ibm.com. Please include your full external mail address so we can check we have sent it to the right place.

Recent TCP/IP APARs

AQ60642 is an update to the ALCS TCP/IP support that improves performance by providing a quicker response to input IP traffic, whilst using less resources.

To apply this update in its APAR form it is important to apply follow on APARs, AQ70445 and AQ71012, at the same time. This is necessary to avoid problems found in testing AQ60642. A single PTF will be produced to encompass all three APARs.

Partitions greater than 2Gb

With the new z/Series hardware and software it is possible to run ALCS in a very large operating system partition. Most ALCS customers do not use partitions larger than 2Gb, but if your installation plans to do this, you will need to apply a fix to your ALCS system.

If ALCS runs in a partition that has more than 2 Gigabytes of REAL storage on z/Architecture, ALCS requires a change so that the LOAD REAL ADDRESS instruction will not fail with a ABEND0D3. This can occur if the real address to be loaded is above 2 Gb. We can provide a simple solution for those of you on z/Series hardware and software and in due course will issue an APAR applicable for all users.

Please contact us at alcs@uk.ibm.com if you require the fix or have any questions on this matter.

Reminder to re-assemble TCP/IP CSECTs

Please remember that when we ship maintenance updates to the ALCS TCP/IP components that you need to re-assemble the CSECTs with your TCP/IP macro libraries to avoid compatibility problem between ALCS and TCP/IP. We use ++HOLD statements to remind you that this action is required.

In the APAR AQ62270 originally published on this website we failed to include a ++HOLD statement. The superseding PTF UQ69455 does have the ++HOLD statement. Please be aware if you are applying the APAR version of this update to re-assemble the ALCS TCP/IP CSECTs.

Maintenance Update Tape 6 shipped

We have recently sent to each ALCS customer a 3480 cartridge tape labelled DXC006. This tape contains all ALCS 2.2.1 and IPARS 2.2.1 PTFs issued from October 2001 through to May 31st 2002. Accompanying the tape is the usual documentation. The tape is sent via conventional mail and may take some time to reach some of you. If you do not receive the tape in the next few weeks please let us know by sending a note to alcs@uk.ibm.com Please include your full external mail address so we can check we have sent it to the right place.

ALCS Product Survey 2002

Many thanks to all for taking part in the ALCS Product Survey 2002. After a little chasing we finally managed to receive replies from 23 of the ALCS license holders - that is nearly a 90% response rate!

For those of you who are interested we have gathered the numeric results and presented them in a document below. The colours and shading used have been chosen to make the graphs readable on either a colour screen or when printed in black. If you would like to look at the results then please download the file from the following link.

  ALCS Product Survey 2002 - Results

We find the comments you write most useful and we are acting upon them now. If you have any further comments then please contact us at alcs@uk.ibm.com.

ALCS running on z/OS

ALCS is running on the latest OS/390 release. z/OS is the name of the new operating system which extends OS/390 into the 64 bit arena.

ALCS requires a small change, APAR AQ52169 (PTF UQ58664), to run on the Z/OS operating system. The reason for this update is because one of the operating system control blocks that we refer to has been updated in the new 64-bit architecture.

Update 21 June 2002. Another change required is APAR AQ51969 (PTF UQ64927). This should be applied to ALCS before migration to z/OS and then no further action is needed. If you have migrated to z/OS without this fix we suggest you apply it and then force the re-assembly of ALCS programs that refer to the CO0DA macro. The GTRACE macro (SYS1.MACLIB) which is imbedded in the ALCS CO0DA macro has changed length. We have repositioned the location of GTRACE to the end of CO0DA. Forcing the re-assembly will ensure that consistent offsets are used. The members that require re-assembly are : COMB, COME, DXCCOLC, DXCCOLD, DXCCOMC, DXCCOMD, DXCCOME, DXCCOMI, DXCCOMM, DXCCOMP, DXCCOMR, DXCCOMU, DXCCOMV, DXCCOMX, DXCINF, DXCINTC, DXCINTX, DXCSND and DXCSOCA.

Both these changes will be supplied on maintenance tape 6 that will be sent out during July. No other changes are required to ALCS to run under z/OS.

Storage Constraint Relief

AQ56304 moves the sequential file buffers above the 16MB line. These buffers are page fixed and so result in real storage constraint which restricts the number of ALCS tests systems that can run concurrently in the same operating system. With this enhancement the constraint is now relieved.

Our thanks go to Jorge Widmar of IBM Brazil for his assistance in the development and testing of this important modification.

DECB PTF and documentation available

UQ66601 is a major enhancement to ALCS, providing support for Data Event Control Blocks (DECBs). DECBs provide an extension to the ECB levels, allowing a higher number of concurrent find/file requests.

An application program can obtain and use a DECB as an alternative to using an ECB level. Although a DECB does not physically reside in an ECB, the DECB fields specify the same information without requiring the use of a level in the ECB, the only difference being that the data level in a DECB can accommodate an 8-byte file address (for compatibility with TPF).

If you choose to use DECBs you are not restricted to 16 levels. An application program can dynamically acquire and release DECBs. The storage that will hold the DECBs comes from entry storage (using part of an overflow type 1 storage unit), therefore the number of DECBs that the application is restricted to is limited only by the amount of entry storage available to the ECB.

The support for DECBs introduces the following changes to the ALCS product: