[Info-vax] Alpha emulator for OSX

[IanD]

On Tuesday, February 9, 2016 at 12:31:06 PM UTC+11, terry-... at glaver.org wrote:
> On Sunday, February 7, 2016 at 8:17:08 PM UTC-5, IanD wrote:
> > They may be changing things ? 
> > 
> > It seems the free product is discontinued and a personal and commercial one is in the works... 
> > 
> > The downloads section has no files listed at all
> 
> There has been a commercial one for a long time (perhaps since the beginning). It has been enhanced on a regular basis.
> 
> The free version's licensing / availability changed a couple times - it had been available for personal or commercial use. That changed to personal / non-commercial use only, and now (as you point out) it doesn't seem to be available at all.
> 
> Most of the other commercial emulators don't have a free version available either, so this seems to be the way that market is structured, unfortunately.
> 
> For AlphaVM, the commercial version is a rather different product. The free version is (was?) an instruction-by-instruction emulator, while the commercial version uses a variety of JIT (dynamic translation) processes for performance. The commercial one also includes many features not in the free version.
> 
> I don't know the reason behind discontinuing the free product, but since it was free and a different codebase from the commercial one, I can't see how it would be cost-effective to continue to offer it, taking time away from development of the commercial version to do more work on something that's given away for free.
> 
> In my case, if there hadn't been a free version of AlphaVM I wouldn't have investigated it enough to purchase the commercial version (I looked at a bunch of commercial emulators back-when and AlphaVM was the only one that had an easily-obtainable download - the other ones just had a "contact us for evaluation" link). But I'm not the typical customer for a commercial Alpha emulator - I use it for hobby / personal use.

I tried some of the others but ran into issues with RDB, because Oracle insisted on using EV56? as a minimum

The other emulators I tried had earlier chipsets than this so RDB would not even install (FreeAXP was one such beast)

I have no way of using an Alpha emulator in a commercial sense either

Disappointing to see EmuAXP taken away altogether though, I found it incredibly stable

I did email them and asked if they had a home license option or would be prepared to offer one at say $100 a year for a home install - They said No and didn't have anything planned :-(

I didn't want/need something that scaled all the way to a full blown production with JIT, but something that supported more memory and a few more disks would have been something I would be happy contributing towards

I'm happy to support free offerings but there is no way I can afford a commercial license, double more so that by the end of this year I'm most likely going to be looking for work! I will not have money the throw around into systems that I derive no commercial return from

I wonder if VSI are giving any thought to a hobbyist license when an x86 version pops out of the woodwork? I know it's going to first be released on certain hardware platforms, probably high end too but I'm hopeful that in time they release a free / home install version for those of us not on the commercial track

Hoff mentioned Vax emulators possibly running into timing issues is they are left to run faster than Vax clock speeds, or at least that what I thought he was saying

I was speaking with someone who performs VMS emulator installs. They did a project for let's say a large government entity that likes to blow up things and they had to make specific changes in the Vax emulator to slow it down as the other systems it interfaced with required specific inputs at specific times from the Vax as part of it's simulation package. The information was told to me in conversation, so I'm deliberately being vague. 

I thought it was interesting in regards to timings of systems, that in some cases, just having the emulator run as fast as it can go isn't always feasible.

I know the same people who sell this particular emulator, go to great lengths to only sell you specific clock speeds matching the original VMS systems sold.  

I/O is another matter. We emulated our testing environment onto a commercial emulator and immediately ran into problems. Why? Because the system had one cpu and a bunch of slow RZ disks. When it was emulated, the I/O ran so dam fast that the cpu immediately hit 100% for any task that was run! Throughput was quicker but a 'slow' system became an immediate complaint of users because the system became immediately cpu bound. 
It's something they don't tell you when you go down the emulator route, that you may see bottlenecks pop up where you had none before