Why I Use Open DCL Lite

1. VMS Hobbyist Program solutions
   
2. DCL Implementations on Windows and Linux
   
3. How I've Used Open DCL Lite
   
4. Notes on Products and Terms Involving VMS and DCL
   
5. Other Useful References
   

The most complete, low cost solutions for enabling OpenVMS DCL command use involve running the actual OpenVMS operating system with licenses obtained through the VMS Hobbyist Program. These solutions involve running OpenVMS natively on VAX, Alpha, or I64 (Itanium) hardware, as well as running OpenVMS on hardware -- eg, a modern day PC -- which is running software to emulate / simulate a VAX or Alpha.

This approach would be ideal for someone that wants to still be heavily immersed in the OpenVMS environment, as long as they own the VAX, Alpha, or I64 (Itanium) hardware, or as long as they use one of the hardware emulators/simulators: Avanti, CHARON, AlphaVM, SIMH, etc.  However, the VMS Hobbyist Program is only available for personal, non-commercial use.

• openvmshobbyist.com's "OpenVMS Hobbyist Program" FAQ,
  HPE's OpenVMS Hobbyist Registration.    <<< Register here <<<
  Those are 2 good "first contact" points for the OpenVMS Hobbyist program.

  The OpenVMS Hobbyist program is NOT for commercial use!
  The 2021-09 link for OpenVMS Hobbyist Registration is still at this hpe.com page!!!

• Migration Specialties "FreeAXP™ - A Free Virtual Alpha".
  Migration Specialties FreeAXP is a freeware version of their Avanti™ virtual machine to mimic Alpha hardware.  It is designed to replace hobbyist and non-critical Alpha systems.  FreeAXP can be hosted on 32-bit and 64-bit Windows systems (from Win7 and higher).  FreeAXP is also supported under VMware, Oracle VirtualBox, Apple Boot Camp, etc.

  Note:
  Some versions of FreeAXP (eg, V2.4.4.537) work with WinXP.  And there's very likely others.  But WinXP is no longer listed as a host system on their FreeAXP.html page.

  FreeAXP is free for both commercial and personal use!  It is compatible with the OpenVMS Hobbyist Program.  It is suitable for hobbyist and non-critical systems.

  FreeAXP provides a virtual AlphaServer 400 with 1 CPU, along with the following user configurable components:

  • 32 - 128MB of virtual memory,
  • up to seven storage devices,
  • one physical CD-ROM,
  • two 100Mb NICs,
  • two virtual serial ports (1 console, 1 terminal).

  FreeAXP would probably be my first choice for an Alpha emulator simply because its web site is easy to understand and explore.

  Hint:
  FreeAXP has the "out-of-the-box" disadvantage of 100% CPU utilization -- like most emulators. However, the CPU utilization can be dropped to < 1% using ideas from one or both of the following two links:

  • syltrem's 2016-01-31 post in his idleloop.vdisk and Idle loop program thread at openvmshobbyist.com.

  • VolkerHalle's 2010-04-06 "How to disable Stromasys IDLE tool" post in this thread at openvmshobbyist.com [since it has some FreeAXP specifics].

  Thanks to syltrem for making me aware that the 100% CPU problem can be overcome!

• CHARON-AXP creates virtual Alpha on Windows or Linux system.
  Judging from the facts that: a) a 2016-02-02 Google search for "Stromasys PersonalAlpha" did not show any stromasys.com pages dedicated to PersonalAlpha, b) the Stromasys site seemed to have shifted in the 1.6 years prior to that from being products oriented to being solutions oriented, and c) the Stromasys downloads page still doesn't provide a way (that I can see) to download PersonalAlpha, I'd guess that Stromasys doesn't want its employees to spend any time dealing with PersonalAlpha issues. That's understandable.

  In the past -- on 2013-01-17 -- the PersonalAlpha download did not require registration. However, on 2014-04-28 its download required registration.

  Also, on 2013-01-17 there was a "PersonalAlpha family for 32-bit and 64-bit Windows Freeware" link that said the entire PersonalAlpha family of PersonalAlpha32, as well as PersonalAlpha DS10 and PersonalAlpha DS20 for 64-bit Windows, was free for personal use and commercial use. However, I couldn't locate that page on 2014-04-28, except via its Wayback Machine snapshot: Personal Alpha Plus Personal Alpha.  As of 2020-05, that Wayback Machine snapshot did still have a working Stromasys FTP link for a "standalone for Window" PersonalAlpha32-2.0.20.zip, which is the byte-for-byte, exact same version that I downloaded originally on 2013-01-07. It's probably much safer to download it using that Wayback Machine FTP link, rather than using some nebulous shareware / download site.  Alternatively, if you had a 64-bit host processor, then you would probably want to try the "Personal Alpha DS10" or "Personal Alpha DS20" links on that Wayback Machine page.

  PersonalAlpha was not available for free when I started looking back in 2002. If I was starting afresh today, I might go ahead and register (if necessary), download PersonalAlpha (assuming it is still available), read its license to determine if it is free for personal use (and possibly even commercial use), and try it, in conjunction with the VMS Hobbyist program. PersonalAlpha still seems worthy enough to test as a viable solution for personal, non-commercial use for someone wanting to still be heavily immersed in the OpenVMS environment.

  The biggest PersonalAlpha disadvantages that I can think of are: it is not open source, and it might also have the 100% CPU utilization problem (like FreeAXP when run immediately after installation). The possible "high CPU utilization" problem might be solvable with one of the 2 links provided above in the Hint for FreeAXP.

• EmuVM's AlphaVM-Free emulator.
  According to EmuVM's home page (as of 2016-02-02 and 2017-11-16), the AlphaVM-Free product has been discontinued.  Furthermore, Alpha-VM Free installation packages do not seem to be downloadable from either emuvm.com or the Wayback Machine.  Consequently, I've gutted the bulk of this section.

  EmuVM's AlphaVM-Free emulator was a free, performance limited, feature restricted version of their commercial AlphaVM virtual machine that hardware emulates an Alpha AXP system including its peripherals. AlphaVM-Free was available for 32-bit and 64-bit Windows and for Debian Linux x86-64.

  No longer available for commercial use!
  By mid-2015, AlphaVM-Free was available only for non-commercial use.
  That apparently changed sometime between mid-2014 and mid-2015.

  Disadvantages:

  • AlphaVM-Free was limited to about 1/10 of what it could be in their AlphaVM-Pro product.
  • AlphaVM-Free could *not* release control back to the host system when it is effectively idle, so it would likely eat up 100% of the CPU.  In my mind, that would make it inferior to FreeAXP, PersonalAlpha, and SIMH, since there is some way with all 3 of them to overcome 100% CPU utilization.  That disadvantage is probably why the EmuVM home page (as of 2016-02-02) says the AlphaVM-Free product had been discontinued.
  • Alpha-VM Free installation packages do not seem to be downloadable from either: emuvm.com or the Wayback Machine.

  Consequently, I recommend avoiding AlphaVM-Free due to its last two strong disadvantages.

  But if you have a business, you might consider their for-pay AlphaVM product.

• Trailing Edge's Computer Simulation and History SIMH simulator (V3.11-0, 2020-02-13).
  simh at GitHub (actively updated SIMH v4.0 - 2019-01 or newer).
  SIMH is an open source, free, highly portable, multi-system hardware simulator. In particular, it can simulate the VAX. If I was starting afresh today, this would be my 1st choice if I insisted on open source; otherwise, it would be my 2nd choice (after Migration Specialties' FreeAXP or Stromasys' PersonalAlpha family). It can also be used in conjunction with the VMS Hobbyist program. It is well known to be a viable solution for personal, non-commercial use for someone that wanted to still be heavily immersed in the OpenVMS environment, though some folks say it is slower.

  The most major disadvantage that I can think of would be the constant running of the CPU to accomplish the hardware simulation, similar to the "just installed" experience from the 3 emulators mentioned above. But the SIMH V3.10-0 Users’ Guide, simh_doc.pdf, says the SIMH command SET THROTTLE can be used to throttle the CPU via a) number of instructions per second, or b) percentage of host time. Also, the SIMH "VAX-11/780 Simulator Usage" document, vax780_doc.pdf, says there is a SET CPU IDLE=VMS command which will try to detect when VMS is in its idle loop. So one or both of these should greatly lessen the "100% CPU usage / overheating PC" problem.

  In 2020-05, I noticed at GitHub that VAX model simulators exist for: VAX/11 730, VAX/11 750, VAX/11 780, VAX 3900, VAX 8600/8650, MicroVAX I & VAXStation I, MicroVAX II & VAXStation II, rtVAX 1000 (or Industrial VAX 620), etc.

There are other VAX and Alpha emulators, but FreeAXP, PersonalAlpha, and SIMH seem to be the most mature free emulators (that are still downloadable). For more emulator info, see the list of VAX and Alpha simulators on the VMS Hobbyist Registration page, or see some of the See Also links at the bottom of this page (especially INSOM's VMS and emulation links page, the archived HoffmanLabs page, and the Wikipedia pages), or just explore with your favorite search engine.

For someone that doesn't own VAX, Alpha, or I64 (Itanium) hardware, can't afford to buy it, and for one reason or another can not or does not want to use the emulator / simulator approach, the only other options (I'm aware of) to utilize OpenVMS DCL style commands are one of the following DCL or partial DCL implementations that run natively under Windows or Linux.

And for someone that wants to use DCL commands from within Windows (or Linux), regardless whether they have or have not setup a real OpenVMS system -- either a low cost non-commercial one based on the OpenVMS Hobbyist Program license(s) mentioned above or a more costly commercial one -- they would still need to pursue one of the following DCL or partial DCL implementations that run natively under Windows or Linux.

Back in 2002, when I was antsy for the familiar DCL commands:

• I had no money to buy hardware that ran OpenVMS natively, eg, VAX, Alpha, etc.
• I already knew that running the PC's CPU "with the pedal to the metal" was not a good idea due to my experience running a program that used all the CPU's idle time to search for chemicals that were good candidates as cancer fighting drugs. That PC had a bad problem of overheating when the drug candidate search was running for long periods.
• I had too much time invested in getting oft-used applications going on my Windows PC to switch everything over and convert it totally to OpenVMS.
• My computer had way too little memory to run Windows simultaneously with a hardware emulator.
• I ruled out using the SIMH simulator -- the only simulator that I was aware of at that time -- due to the overheating problem (even if SIMH was throttled) and especially due to the lack of memory.
• I wanted to use DCL-like commands at the MS-DOS Prompt to provide functionality not available with the Microsoft commands. This last one was a very important consideration to me.

Fortunately, there were -- and still are -- some DCL (or partial DCL) implementations in the Windows and Linux worlds.

• Advanced Systems Concepts XLNT
  It's quite good, but not free. I evaluated a trial version back in 1998. However, after the trial period expired, I ruled it out for permanent use due to it not being free and for being too costly for me personally to buy. My latest recheck (circa Jul 2015) revealed:

  • they used a "trial period followed by minimum $349 payment" marketing approach,
  • their XLNT is a rich implementation of DCL with boatloads of Windows extensions,
  • their web site is outstanding at being able to very quickly obtain info to evaluate the product,
  • they don't support logicals.

  This could be my #1 or #2 commercial choice for using DCL within a Windows environment, if I had ruled out the hardware emulator approach, and IF they supported logicals. But they don't support logicals, and that's a "show stopper" to me. If the lack of logicals is not a problem for you, and if you're willing to plunk down the money, and if you want an excellent facility to manage your batch queues, along with providing a registry interface, a dll interface, a CGI interface [wow! -- is that really DCL as CGI?], etc, then check out XLNT.

• Sector7 VX/DCL
  It's probably very good, judging by their documentation. It appears to be available for Unix/Linux only, not for Windows. So to use it on Windows, you would probably have to use some sort of virtualization software to run Linux under Windows. I ruled it out since: a) it is apparently not free, b) I wasn't ready to switch everything over from Windows to Linux, and c) I simply wanted to use DCL-like commands at the MS-DOS prompt.

  This might very well be my #1 commercial choice for using DCL within a Linux environment, if I had ruled out the hardware emulator/simulator approach, and IF the feature set is as rich as the command list indicates, and IF the price is right.

• Transoft Open DCL^[2] (now Advanced Open DCL)
  It's also good (judging from what every reviewer I've seen says), but it's not free, so I ruled it out due to not being free and for being too costly for personal use.

  As of 2018-08-20, I couldn't find a page dedicated to Open DCL by exploring on either the Transoft web site or the Advanced web site. It seems that Transoft / Advanced is emphasizing their integrated services rather than allowing access to the single Open DCL product.

  Open DCL would very likely be my #1 commercial choice (now) if I needed a fairly heavy duty DCL that is available in both Windows and Linux environments, and I had ruled out the hardware emulator/simulator approach, and IF the price is right. After all, I've already got years of experience with its Lite version under my belt.

• Accelr8's Open DCL^[2] and Open DCL Personal Edition
  Accelr8 Open DCL is an old version of what became known as Transoft Open DCL^[2] (after Transoft acquired Accelr8's migration tools in Aug 2004). Accelr8 Open DCL was not free (back in late 2002 when I was looking). I don't recall if Open DCL Personal Edition was still a product back in late 2002. But, in any case, it was still not free. The license for both of these products did not permit "free for personal use".

  Neither of these products seems to be available anymore. They are listed more for historical purposes.

• Accelr8's Open DCL Lite
  Accelr8's Open DCL Lite^[2] was free at the time I downloaded it back in late 2002 -- and it still is free via Internet Archive Wayback Machine, some DECUS archives, and de.openvms.org.

  Open DCL Lite had an acceptable SEARCH (though it didn't include some of the useful asterisk lines that the VMS version does), a nice DIFF (except for the problem of an erroneous difference sometimes reported near the end of files), a useful (though imperfect) DIR, DELETE, and TYPE, a very useful (user-expandable) HELP system, a few lexicals, and super useful (sufficiently VMS-like) logicals and symbols, etc.

  I've found DCL Lite v2.21 to be extremely useful -- for 18+ years now.

  But it's only a partial DCL implementation. And it's got its errors and quirks. For some more information...

  • See my Analysis of Pros and Cons of Accelr8 Open DCL Lite v2.21 for a comparison of Open DCL Lite with a) portions of OpenVMS DCL that I've missed, and b) Transoft's (ie, Advanced's) full commercial grade Open DCL.

  • Also, (at least) skim Comparison of PC-DCL vs. Open DCL Lite to see why I consider Open DCL Lite to be superior to PC-DCL as a "day in and day out" DCL implementation, but how PC-DCL can be used to provide some functionality which Open DCL Lite is missing.

  • Glance at Mutual Extensibility of Open DCL Lite and PC-DCL to get some ideas on how PC-DCL and Open DCL Lite can coexist and mutually extend one another.

  • Finally, briefly look at the How I've Used Open DCL Lite section below.

  Then if you're still interested in Accelr8 Open DCL Lite...

  • Follow the guide to Downloading and Installing Accelr8 Open DCL Lite.
    It's a step-by-step guide to get up and running with a very useful DCL Lite shell.

  Request to not bother Accelr8, Transoft, or Advanced about Open DCL Lite:
  But please remember that Accelr8 does not own the Open DCL Lite product any longer and should not be contacted if you have any questions about it.
  
  Also, please remember that Transoft has apparently retired Open DCL Lite, so they (and their new owner: Advanced) should probably not be contacted if you have any questions about that free, pared down "Lite" product, since their bread-and-butter business is commercial migration services and consulting.

• Michel Valentin's PC-DCL (circa 2014-05-22) snapshot on Wayback Machine
  "MichelValentine / PC-DCL" source at github
  PC-DCL was free, but very incomplete, when I initially evaluated its v4 beta for Linux in Mar 2007.  Most notably, it had no VMS-style DIFF or SEARCH command. Since those were the two main utilities I was searching for, I soon forgot about PC-DCL.

  While creating this "Why I Use Open DCL Lite" web page in early 2012, I came across some comments by folks that seemed satisfied with PC-DCL. So, since it's free, I decided to reevaluate it. An initial static analysis of the contents of the PCDCL_Setup_V407.exe setup file -- which is still downloadable (circa 2021-09) from the PC-DCL home page at the Wayback Machine -- revealed that there are a good many more features in PC-DCL than there are in Accelr8 Open DCL Lite, even though it still did not have a DIFF or SEARCH command. A much more thorough hands-on analysis ensued. See my Comparison of PC-DCL vs. Open DCL Lite for a fairly detailed analysis of PC-DCL, which focused on evaluating whether PC-DCL works better than Open DCL Lite, or if it can be used as an adjunct to Open DCL Lite.

  If the PC-DCL summary above doesn't turn you off too much or if the detailed comparison doesn't turn you off too much, then you might explore PC-DCL as a viable option for getting an OpenVMS DCL subset on either Windows or Linux. Or you might consider installing it (like I sometimes do) alongside Accelr8 Open DCL Lite for occasionally providing some useful functionality missing from DCL Lite.

  Remember: PC-DCL is free for either personal or commercial use!

  PC-DCL source available at github:   <<< NEW resource discovered 2020-05-18
  Michel Valentin's PC-DCL is the only one of the native Windows or Linux DCL implementations that has open source available.  I'll leave it to you to explore MichelValentine / PC-DCL at github.

  P.S. Sometimes Valentin's PC-DCL has been referred to as "microDCL".

I experimented with the free Accelr8 Open DCL Lite, developed the site-wide SYLOGIN.COM and user-specific LOGIN.COM to behave in a flexible manner to suit my purposes, converted many of my VMS DCL (.COM) command procedures into ones that had .DCL filetypes (in order to avoid confusion with the .COM filetype used by some old MS-DOS executables), got my VMS DCL "environment" of logicals and symbols converted into something usable with MS Windows, added a daily cleanup DCL Lite procedure into Windows task scheduler, enhanced my VMS CHD (change directory) script to be extremely useful in the MS Windows environment, developed some command procedures to run DCL Lite from either a DCL Lite box or a MS-DOS Prompt or CMD Prompt box, generalizing as much as possible so it could be easily run on a brand new system from a highly portable flash drive.

Over several years, I've used DCL Lite as my preferred shell environment. And I've used it to develop an evolving help system to quickly display much of the documentation that I'd collected on lots of components in my set of development tools (which I had begun working with but could never seem to remember what their calling conventions were since they came from a variety of different sources in the OpenVMS, Windows, Linux, and WWW worlds).

The result is that I've got a command shell which is OpenVMS-like enough to satisfy my (previous) desire to still work in a real VMS environment -- a desire which apparently is never going to be fulfilled. I've learned to put up with many of DCL Lite's idiosyncracies, deficiencies, and outright errors. And for those DCL Lite problems that are intolerable, I've discovered or developed workarounds and/or superior solutions using various good tools in the Windows environment -- from Microsoft, Borland, Digital Mars, UnxUtils, ComponentSoftware, and some that I periodically download from a myriad of internet sources. I'm heavy into open source solutions. And I almost always utilize free (as in "no cost"), non-shareware, optional-donationware solutions that are oftentimes free (as in the GPL v2 definition of "free"). I'm satisfied enough to no longer yearn to be working in a real VMS environment, comfortable with this "WinXP/Win7/Win10 with a taste of Linux but using a DCL-like shell" environment.

Since Accelr8's Open DCL Lite is my primary command shell, some of the software made available on this site might use make files and documentation that explains how to build and run the software with Open DCL Lite commands. One such (originally planned) example was the makefile for building my enhancement to the IJG software to decode SFW98 format .sfw file's non-standard arithmetic encoding. Since that enhancement was originally planned for public release at one of the pages/links feeding from the SFW conversion portal for Seattle Filmworks/Photoworks .sfw files, a good explanation of how to locate, download, install, and configure Accelr8's Open DCL Lite seemed necessary (at the time) to help a new user get up and running with a functional DCL Lite shell. This present page is just an introduction to that detailed Accelr8 Open DCL Lite download, installation, and configuration information.

If you want to now download and evaluate Accelr8 Open DCL Lite, click here.