Thursday, December 28, 2006

Happy New Year

Just one final note for my last post of the year. 2006 turned out to be a good year for the mainframe. I found it hopefull to see that not only professional people start to value the mainframe again. It also gets more and more attention in the press - and especially positive attention. And whether we like it or not, they play a great role in forming the public opinion, only this time, it's in our favor.

I can only wish every one the best for 2007. Thanks to those who visit from time to time or put a link on their own page. And I hope to meet you again in January at my little blog space.

Tuesday, December 26, 2006

IBM and Oracle initiatives

Last october, IBM and Oracle announced "a strategic initiative to collaborate on the sales and marketing of a series of enterprise business solutions with Oracle applications and technology for Linux on System z in order to target the business requirements of large and medium size enterprise customers and meet growing market demand."

On this IBM page the implications of the announcement are described as follows : "With today’s announcement, Oracle is extending the portfolio of products available on the IBM System z9 platform with a comprehensive set of both database and application solutions which Oracle intends to enable for Linux on System z. This could mean new opportunities for you to take advantage of the advanced functionality of Oracle applications on a premier Linux environment, benefiting from the core strengths of the IBM System z9 platform."

I'm not a specialist on Oracle applications but when I try to read between the lines, I have the impression that 'Oracle E-Business Suite 11.5.10.2' will be able to run on zLinux. "Will be" is the right phrase though, because up to now it's not possible.

There is however a nice redbook on this matter due to be published in February 2007. But ther's already a draft available : Experiences with Oracle 10gR2 Solutions on Linux for IBM System z. "This IBM Redbook describe experiences gained while installing and testing several Oracle solutions, such as:
- Single Instance of Oracle Database 10gR2,
- Including sharing ORACLE_HOME and Cloning Oracle databases,
- RAC Instance of Oracle Database 10gR2 using raw devices, block devices or OCFS2 files
- Oracle E-Business Suite 11.5.10.2 with a split configuration database on Linux on System z Oracle AS10g"

Friday, December 22, 2006

IBM making movies

This is not really a comment on mainframe but still.
First of all I find that IBM is making very creative ads lately. I guess they have a whole department over there for this. I posted 'The Heist' earlier this year and I would like to add another one. As you see, not only creative, but sometimes funny too.



IBM didn't start yesterday with making movies. To illustrate this I found a movie from 1956 at the Prelinger Archives. Do we already find the precursor of parallel sysplex in 1956 on an IBM machine for military purposes ? The time frame was quite different then. So I surely won't be searching for any other parallels with current times. Or as one comment at the Prelinger Archives says : "(...) Ignore the usual patriotic stuff... or smile."

Tuesday, December 19, 2006

Mainframe Growing Like It's 1979

As the year is closing down, surveys of the past year and predictions for the coming year are made everywhere. Of course, our interest mainly goes to commentaries on the mainframe, like this one at Enterprise Systems.

On the other hand, 2006 was a resurgent year for mainframe boosters. Big Iron enjoyed three strong quarters—including a Q3 in which it recorded 18 percent year-over-year growth in MIPS shipments—and helped IBM grow its server market share, thanks in large part to System z (see (http://www.esj.com/Enterprise/article.aspx?EditorialsID=2316).

To be sure, there was a downturn of sorts—mainframe sales dipped in Q2—but that was also ahead of IBM’s z9 Business Class (BC) and z9 Enterprise Class (EC) system refresh. What’s more, IBM introduced a new dedicated processor engine (zSeries Integrated Information Processor, or zIIP) and announced a $100 million investment to simplify mainframe management and programming.

All in all, 2006 was a great year for mainframe pros. As you’ll see, 2007 might be even stronger.

All in all a great message to conclude the old year and start with the new one. I'm not sure whether I'll get to posting again for this year. But with the end of the year in sight and the mainframe "growing like it's 1979', I suggest we start 'partying like it's 1999'
(yes, Prince )

Monday, December 11, 2006

z/OS 1.8 Installation Planning Checklist

I've been browsing through Techdocs again and came across this z/OS 1.8 Installation Planning Checklist. This is an interesting document which is "to be used as a supplement to existing product publications". For those who are preparing a migration towards z/OS 1.8, the list was last updated at the end of November.
This reminds me of another lesser known source of information for people upgrading to a new version of z/OS : the ‘zSeries Platform Test site'. This is a site where a team of IBM people write down their experiences at migrating to a next z/OS release. They work in a parallel sysplex environment and bring you a detailed report of their migrations : planning, migration, problems during migration, interaction with other products (DB2, IMS, Websphere, CICS . . . ). They also offer some sample configuration files . . . Unfortunately there's no publication on z/OS 1.8 yet. I'll keep you informed when it turns up. The last one is 'z/OS V1R7.0 zSeries Platform Test Report for z/OS and Linux Virtual Servers'. A list of earlier publications can be found here.

Wednesday, December 6, 2006

IBM to acquire Consul

On the Consul site we read that "On December 5, 2006, IBM and Consul entered into a definitive agreement for IBM to acquire Consul". On the IBM site, you can find the entire press release.
Consul is a leading provider of compliance and security audit software that helps clients track, report and investigate non-compliant behavior, such as unauthorized activity by information technology administrators or other users.
I know them best for their mainframe products like Consul/RACF but apparantly it's their cross site coverage that makes this company an asset to the IBM products. Or as we find on their site :
"Consul's 20 year history as the leader in audit and compliance software means you can rely on us for the most comprehensive solution available on the market. With the first and only solution for log management, privileged user monitoring and audit (PUMA™), and security audit and compliance reporting across the enterprise, from perimeter to network devices, to applications, databases, operating systems, and the mainframe, the Consul InSight Suite meets your needs to track, report on, and investigate non-compliant behavior.
Consul offers two distinct industry acclaimed product suites:"

Tuesday, December 5, 2006

IBM Archives

As I was making a presentation on tape storage I came acrosse this page called the 'IBM Archives' on the outskirts of the IBM website. There's some great historical material in those archives. You can find the history of the IBM logo (from globes to stripes). This one was used from 1924 till 1946.

There were only three others since resulting in the current one with eight bars from 1972 onwards. As we see e.g. here on a System/370 :



My first recollection of a mainframe was the 4381 :



This is just one picture in a row of many in the Mainframe Photo Album.
But there's lots and lots more on the site. There's an Antique Attic, a history on cards and tapes etc. There are also some audio fragments of famous speeches, such as a recording of Thomas Watson in 1915 commenting on the "THINK" motto :

"And we must study through reading, listening, discussing, observing and thinking. We must not neglect any one of those ways of study. The trouble with most of us is that we fall down on the latter -- thinking -- because it's hard work for people to think, And, as Dr. Nicholas Murray Butler said recently, 'all of the problems of the world could be settled easily if men were only willing to think.' "
In other words : the place to be for those of us who are getting nostalgic from time to time.

Friday, December 1, 2006

IBM Redbooks

Today I'm stating the obvious of course. Every one knows the IBM Redbooks. But I just added the URL to my links because there were a couple of interesting redbooks this week. People tend to forget soon, but I still find the Redbooks a great initiative as compared to the former manuals we were always cursing because they were unreadable. You can subscribe to the Redbooks Newsletter over here, indicating your interest areas. So, you'll get an update on the site every Monday. Or you can even get real-time updates with the RSS-feeds nowadays.
The first redbook I would like to mention is still a draft : z/OS Version 1 Release 8 Implementation. But the draft is already worth mentioning. The content is too exhaustive to cover entirely here, but here's a foretaste :
This redbook describes the functional enhancements to z/OS® for Version 1 Release 8, (z/OS V1R8). These enhancements that are described are designed to help installations install, tailor, migrate, and configure z/OS V1R8.
This redbook describes the new enhancements as follows:
z/OS Version 1 Release 8 Overview
Installation and migration to z/OS V1R8
Console restructure
CFRM performance enhancements
RMF enhancements
WLM enhancements
.
.
.
The second one is ICF Catalog Backup and Recovery: Catalog RecoveryPlus Update. This Redpaper tells us about IBM Integrated Catalog Forward Recovery Utility (ICFRU) and Mainstar Catalog RecoveryPlus, two tool for ICF catalog backup and recovery. It "provides information and practical examples on how to use the Mainstar Catalog RecoveryPlus product in a catalog recovery situation. It also provides useful recommendations for storage administrators in implementing a catalog backup and recovery plan.
This redbook also provides a variety of practical tests to help you with the
different error scenarios you may find in your daily production activities."

Monday, November 27, 2006

Price change for some Websphere Products

I didn't have much time last week but there was one announcement letter I still want to mention : "Price Action on System z and zSeries Software Program Products". It concerns a price raise on mostly websphere products, more specific :
  • 5655-F81 IBM WS Application Server for z/OS (S&S)
  • 5655-L86 IBM WS Business Integration Server Foundation for z/OS (S&S)
  • 5655-P27 IBM WS Process Server for z/OS (S&S)
  • 5655-R16 IBM WS Enterprise Server Bus for z/OS (S&S)
  • 5655-K13 IBM WS Portal Enable for z/OS (S&S)
  • 5655-I19 IBM WS Message Broker for z/OS (S&S)
  • 5655-K58 IBM WS Event Broker for z/OS (S&S)
  • 5655-G98 IBM WS Message Broker with Rules & Formatter for z/OS (S&S)
  • 5655-P29 IBM WS Extended Deployment for z/OS (S&S)
  • 5698-S37 IBM Tivoli Business System Manager or z/OS (S&S)

The new prices are effective on April, 1 2007.
For Belgium it means a price increase of 4%.
You can check out the announcement letter for other countries.

Tuesday, November 21, 2006

DB2 V9 for z/OS : how close to announcement ?

I don't know how long it's already on the IBM DB2 Website but it indicates that 'DB2 Version 9.1 for z/OS' is "coming soon". There's definitely more and more information to be found about it. The beta program announcement was issued on May 9,2006. There's a 29-page document on this beta program that also sheds some light on the innovations you'll find in DB2 V9. The document focuses on three innovation types : "those which provide insight for the business, those which provide cost savings, and those which improve business resiliency."
The most striking feature IMHO is the "new hybrid data server support for both relational and pure XML storage, with the necessary services to support both data structures".



As was already the case in DB2 V9 for Linux, Unix and Windows, XML data can now be stored in their native format as they are handled as a new data type. Both XML and relational data are under control of the same DB2 engine.
There's a very good introductory article on DB2 V9 in the latest DB2 magazine by Craig S. Mullins, a renowned authority on DB2 for years : DB2 9 for z/OS Roars to Life. By the way, Craig S. Mullins has his own blog on DB2 : DB2PORTAL Blog and an own site with lots of earlier articles on DB2.

As far as preriquisites and migration path are concerned : "Migration to V9 will be only from DB2 for z/OS Version 8 and will prereq z/OS 1.7 Some items will require z/OS 1.8."

z/Journal New Edition

z/Journal has just released its new edition. I've subscribed to the digital edition some time ago (PDF - print only available in the USA). And I must say each time there are some interesting articles. Some examples :
  • "Top Ten Ways To Waste CPU Using DB2",
  • "Linux Worst Practices : What Not To Do"
  • "Understanding Workload Manager : Analyzing Velocity Goals"
  • "10 Ways To Improve RACF Performance
The main article is "Storage Wars, The Attack Of The Tapes" describing how mainframe backup solutions fit into an open enterprise. What are the technical evolutions ? What about protection against tape loss or loss of personal information ? And related to this : what about encryption ?. The opening sentence sets the tone for a nice article by Brandon Hoff : "With the rapid growth of Web commerce, enterprises are struggling to provide storage solutions that are continuously available, satisfy peak demands, and manage storage growth while protecting data from malicious attacks".
You can subscribe to the digital z/Journal edition over here.

Wednesday, November 15, 2006

Just recovering

I accidentally deleted my entire blog fooling around with a new blog. I thought I was deleting my test blog when I was in fact deleting this one. First there was the panic moment, of course. What have I done ? So I went looking for offline pages on my PC but I only found my last posts. But then I found them all back in the Firefox cache of my second PC. Thank God ! So, I'll be putting them all back online as soon as possible.
Well, this should be a fresh start as I see that the layout of new blogs has changed compared to the former ones.

Tuesday, November 14, 2006

SMF Reference Summary

Cheryl Watson is a well-known authority in the IBM mainframe world. Though I must admit that her "Cheryl Watson's TUNING Letter" is way too expensive for me. But still, I findit worthwile to check out her site once in a while. There's a nice Article section of which especially the presentations are worth a look. There's e.g. the "Hot Flashes" that always start off with some survey questions like who's running what version of z/OS, who's using a zAAP or a zIIP etc. The last issue is Hot Flashes #16 dating from August 18, 2006.
Coming back to the title of this post. There's a nice PDF on the site which gives a brief description of SMF records : "Cheryl Watson's SMF Reference Summary. A useful document, though I find the title page with picture and all a little over the top. Perhaps, we Europeans, have a little more down to earth approach on these matters.

Thursday, November 9, 2006

Techdocs : IBM Technical Sales Library

As I have not much news for the moment I would like to draw your attention to a site I really visit regularly : the IBM Technical Sales Library, briefly Techdocs. Do not be misguided by the 'Sales' word, as you'll find lots of helpful technical information, white papers, tools etc. on this page. For example zPCR, the sizing tool when performing an upgrade can be downloaded from Techdocs. Lots of information on recent announcements can be found there. I already mentioned the 3584 slot calculator and a white paper on the zIIP in previous posts.
What I do is just get over there once a week and hit the 'Latest updates' button (right side of the screen). This week there's a technical presentation on the implementation of the new Server Time Protocol : STP z/OS considerations.
I'd say : just check it out !

Monday, November 6, 2006

Tape Cartridge Extended Models up to 700 MB

Another announcement last week was made for the 3592 tape cartridges. There are three new 'Extended Data' models with up to 700 GB rewritable native capacity. The models indicate whether the cartridges are labeled, initialized or not. There are three additional 'Extended Worm' types available. Once again some more capacity on a cartridge. So be it. But what I find interesting are some compatibility issues announced at the same time. On a previous occasion I mentioned one of the drawbacks of the TS7700 Virtualization engine : "The TS7700 connects to the TS1120 E05 but it has to run in emulation mode as a 3952 J1A. This also means you cannot fully use its speed nor the larger 500MB cartridges.". Well, that's been lifted now : "TS7700 will support 700GB using native TS1120 E05 drive support" and the 3592 J1A emulation mode is no longer needed. Apparently no such support will be implemented on the 3494 B10 en B20 Virtual Tape Systems.
Take a look at the software requirements too : z/OS 1.5 is needed for these new media. You will need z/VSE 3.1.2, z/VM 5.1.0 and z/TPF 5.1 for the other operating systems.

Thursday, November 2, 2006

IBM Announcements : DS8000

As I had a day off yesterday (All Saints' Day) I wasn't able to comment on the new storage announcements. I'm just focusing on the DS8000 in this topic. Last summer, more particularly on 22/08/2006 the new Turbo Models of the DS8000 were announced using the new POWER5+ processors. The announcement included also the new 500GB 7.2K FATA disks and 4Gb Fibre Channel and FICON host adapters. (By the way : the 500GB FATA disks were also announced on the DS6000). Last Tuesday 31/10/2006 additional announcements followed. One of the announcements is the withdrawal of these very models announced in august. The reason is that the DS8000 machine is no longer referred to as the 2107. It is replaced by the 2424 machine type. In addition three machine types are added : 2421, 2422 and 2423. The last digit indicates the warranty period. So this is a major change to the DS8000 : from now one the client can choose the warranty period for the DS8000 instead of having to take the 4-year warranty directly.
Another enhancement on the DS8000 is the HyperPAV feature "planned to be offered on z/OS 1.6 and later releases in November 2006. It "is designed to enable applications to achieve equal or better performance than with the original PAV feature alone while also using the same or fewer z/OS resources.""
What's the difference with dynamic PAV : PAV aliases are pre assigned and Workload manager in z/OS can then dynamically reassign addresses when needed if it sees that some devices need more and others need less. This is mostly reactive, and it takes z/OS cycles to do. With HyperPAV, the aliases are not pre-assigned. Aliases are in a pool and are assigned only when needed. It is done in a more on-demand way. It doesn't use z/OS cycles to reassign Aliases. It does not depend on Workload manager function. It minimizes the number of aliases assigned and therefore, the number of addresses used. The number of PAV-aliases needed may be reduced, taking fewer from the 64k device limitation which is important to large customers. The feature is exclusively offered by IBM and requires purchase of the billable HyperPAV feature and a PAV license on the DS8000 and it also requires z/OS V1.6 and later releases

Tuesday, October 31, 2006

The mainframe making its comeback ?

Urban Dance Squad was definitely not singing about the mainframe in their song called 'Comeback' :
"What a drag to see an old bag
sweatin'n'fakin'
for a comeback"
But still it could've been a prophetic message in 1991. It sure seemed to come true in the years to come, but I have the impression that the tide has turned the last months (if not the last couple of years). Take a look e.g. at a former post here about the revenue of IBM in 3Q2006 and the large contribution the mainframe had.
Moreover (and perhaps even more important) there seems to be a turning point in the perception of the mainframe. It does not only gain the credit it deserves in the business world but also the media seem to pay more attention to it. As an example, here's two articles I stumbled across lately. The first is an interview
"In a sea of middle-aged men roaming around the Share mainframe conference this summer, there walked an anomaly: Kristine Harper. (...) Harper defies the stereotype around mainframers, being young
and a woman."
You can read the entire interview here . The second is a recent article on the CNN site about the comeback of the mainframe that you can find here .

Monday, October 30, 2006

Trial Code Download: IBM CICS Tools

Anyone interested in trying some CICS Tools now has a 60-day opportunity.
It concerns the following tools :

    CICS Batch Application Control 1.1
    CICS Business Event Publisher for MQ Series 1.2
    CICS Configuration Manager 1.2
    CICS Interdependency Analyzer 2.1
    CICS Performance Analyzer 1.4
    CICS VSAM Copy 1.1
    CICS VSAM Recovery 4.1
You can download them from the IBM Website. There is also a support formula when you have any problems with these products.

Wednesday, October 25, 2006

IBM Announcements : PL/I 3.6

New Announcements by IBM are usually made on Tuesday. So you may be expecting to see some announcements pop up on wednesday when thy prove to be interesting for the mainframe world. Yesterday 24/10/2006 a new release of PL/I was announced PL/I V3R6. It will be available on 27/10/2006.
New in V3.6 are :
  • DB2 V9 support
  • Performance improvements
  • Usability enhancements
  • Quality improvements
  • Serviceability improvements

One prerequisite to pay attention to : z/OS V1.6 (or later) is required.

Monday, October 23, 2006

The Heist - Linux consolidation

We used this video in a presentation last week. Well, here it is . . . with sound.

Thursday, October 19, 2006

IBM Earnings up again in 3Q2006

IBM announced its earnings for 3Q2006 and they made a really good quarter - especially in the mainframe branch. You'll find more detail on this page. You can read the press release or view the presentation on the subject. One quote : “Systems and Technology Group (S&TG) revenues totaled $5.5 billion for the quarter, up 10 percent. S&TG revenues from System z server products increased 25 percent compared with the year-ago period. Total delivery of System z computing power, which is measured in MIPS (millions of instructions per second), increased 16 percent.”

Tuesday, October 17, 2006

Is the zIIP cost effective ?

At Techdocs you can find the first White Paper with measurements for the zIIP. The paper describes some measurements done in IBM’s Laboratories utilizing z9 zIIP hardware and software. Four types of DB2 V8 workloads were measured:
- SAP OLTP exploiting Distributed Relational Database Architecture (DRDA – using DB2 Connect)
- Business Intelligence (BI) batch direct attached
- SAP BW query exploiting DRDA
- DB2 Utility
The results seem to be quite promising !

Wednesday, October 11, 2006

Server Time Protocol Announcement

The concept of the Server Time Protocol (STP) was first introduced when the System z9 was announced July 2005. Now the successor of the Sysplex Timer is officially announced. The announcement can be found at the IBM Offering Information pages. Though it won't be available until January 31 2007.
There's already a redbook available too : Server Time Protocol Planning Guide (SG24-7280-00).

The same announcement also announces the NRF (Non-Raised Floor) feature for z9 BC. This should be available from November 17 2006 onwards.

Tuesday, October 10, 2006

International zSeries Oracle SIG

I stumbled across this site when looking for information about Oracle on mainframe. What's definitely interesting about this site is the large amount of presentations from their conferences. The presentations of this
Special Interest Group can be found here.

On a different note I see that I'm tackling very different subjects next to each other. But hey, that's probably just the very nature of blogging itself. So I'll (and you will) have to live with that.

Friday, October 6, 2006

Dolmen Newsletter N° 5 bis + correction

Dolmen System z Newsletter has been sent to the subscribers on Tuesday. It can be found here.
We found however that we made a little mistake in the announcement section. We mentioned that the Sysplex Timers would be withdrawn from marketing by the end of the year. This, however, is a worldwide statement not applying to European countries submitted to the RoHS rules. The timing was correctly indicated in Newsletter N° 4 with this schema :

IBM's Five year march to Mainframe Simplification

z/OS 1.8 has of course lots of new features. When looking at features disappearing from this release there were some features lifted from 'msys for setup' and 'msys for operations' was even withdrawn. Enhancements for 'msys for setup' were planned and a completely new interface and infrastructure were promised for 'msys for operations' . . . for some future release.
Now IBM is shedding some light on this with their 04/10/2006 announcement on this subject. IBM will invest $100 million in the coming years "to enable technology administrators and computer programmers to more easily program, manage and administer a mainframe system -- as well as to increasingly automate the development and deployment of applications for the mainframe environment". Main areas include :
"1) Automated configuration checking -- to make it easier for information technology administrators and computer programmers to predict and avoid technical problems.
2) Modernizing the mainframe user interface -- including network configuration, systems management, and data center hardware configurationdesigned with both existing IT staff and the new generation of IT workers in mind.
3) Improving software asset management technologies -- to make it easier for users to control software costs and, as well, simplify and automate the acquisition of software services.
4) Modernizing the mainframe's development environment with visual tools that enable novices to quickly learn how to program for the mainframe."
For more detail : check out the announcement.

Monday, October 2, 2006

Dolmen Newsletter N° 5

Dolmen, a Belgian business partner of IBM, brings out a newsletter every 4 months on System z. You can find previous versions here : Dolmen System z Newsletter. There are French versions available too. Unfortunately no English version, but I gather most of it will make its way into this blog. I happen to be very closely involved with this newsletter. So I'm very proud to inform you that N° 5 is on its way any day now. It covers topics like service delivery, upgrade information on z/OS 1.7, 1.8 and several recurring topics like EOS dates of operating systems and software. Hints, tips and interesting URLs. Just check it out !

Friday, September 22, 2006

FICON Converter

We all know the good old ESCON converter, but there's already a FICON converter too. This converter is designed to 'protect' your ESCON investment. It is attached to the host via 1 or 2 Ficon channels. It converts the protocol for connectivity for multiple ESCON devices with a maximum of 12 outbound ports. It also gives you the opportunity to eliminate costly ESCON directors. Here's a graphical representation :












They are distributed (as far as I know now) by McData and OpticaTech. They have different names but I think it's exactly the same fabric with another label on it.
I'll come back to this when I've got more information on this.

Thursday, September 21, 2006

Techdocs & 3584 Slot Calculator

Techdocs is one of those places IBM created which to me are underestimated. I try to check it out quite regularly as you can find lots of information, white papers, tools etc. on Sytem z and storage. In fact it's broader than that also e.g. covering System i and p. You find techdocs here
One document (excel sheet) that caught my attention today is the 3584 calculator. You can give in your configuration of your 3584 and it gives you how much TB you have available. You can also use it for sizing a 3584 playing with number of drives, number of I/O slots, number of frames etc. Here's where you can find the slot calculator

Tuesday, September 19, 2006

TS7700 The drawbacks

I've been doing some reading on the TS7700 Virtualization Engine and there are a few items I would at least take into consideration when choosing a virtualization solution. I'm assuming readers are familiar with the TS7700 concepts in general.
First of all it's big. The difference between the current 216MB on the B10 and the minimum 6TB cache on the TS7700 is huge. There will come an upgrade path from the B20, but NOT from the B10. IBM should've considered giving the cache drawers as an option. In that way cache size would have started at 1.5TB.
There's no more ESCON support on this box. FICON is the future of course, so this is a logical course of action.
The TS7700 cannot connect to a 3494 Tape library, only to the TS3500.
The TS7700 connects to the TS1120 E05 but it has to run in emulation mode as a 3952 J1A. This also means you cannot fully use its speed nor the larger 500MB cartridges.
The GRID configuration "is only available as a plant offering; two standalone TS7700 Virtualization Engines cannot be combined in the field to form a grid". What if you begin with one TS7700 and want to put it in a grid combination afterwards. No can do ?

Monday, September 18, 2006

1st entry

This is just a first note on my blog.
My intention is to write on IBM mainframe topics.
As I have no idea whether I'll be able to post regularly,
I'm just starting this out without mentioning it to anyone.
Should you still come across it : welcome !