Amiga questions you've always been too embarrassed to ask

[daxb]

ARexx has three special variables: RC, RESULT and SIGL

Only RESULT must be activate with "OPTIONS RESULTS". Why is it not active by default? I don`t see any benefit. Do they want to save some Ram or any other reason for it? Anyone with an explanation?

[Nosferax]

Originally Posted by quarkx

Again, I too would say "don't".
if you sell it later, ANY mod actually hurts the resale Value of any Amiga, as 90% of buyers will demand as close to factory as possible.
Even so called "towered" units are Much Much harder to sell, unless they have something like a Mediator board.
"painted" units also are harder to sell, and don't get me on the topic of how many CD TV keyboards were butchered just so idiots could have black keys on their Amiga's. They should ALL be hunted down and shot!

Don't want to necropost buut for those looking to do an A500 in a PC case... You could always try to hunt one of the elusive Bodega Bay from California Access.

[Nosferax]

Not really a question but a bit of lore. ARexx was Amiga version of Rexx which replaced JCL (a leftover from the good old punch card days) on mainframe. My first job fresh out of college was to translate old JCL reporting software to Rexx for the IBM mainframe division in Montreal. Those were used for banking and ATM processsing. Rexx also came bundled with OS/2 on the PC. I coded some at home on my PC running OS/2 but using the ARexx manual as learning material and everything worked!

[thomas]

Rexx never replaced JCL. JCL is still used in batch jobs and started tasks while Rexx is used for user interface and automation scripting. Rexx cannot run standalone, you need some JCL to call a Rexx program.

[Nosferax]

Originally Posted by thomas

Rexx never replaced JCL. JCL is still used in batch jobs and started tasks while Rexx is used for user interface and automation scripting. Rexx cannot run standalone, you need some JCL to call a Rexx program.

Correct, I misspoke. Blame it on english not being my first language. The rest still applied though.

[Tiago]

Some people like me still work with JCL and COBOL in banks... after so many years this language still resist. I never worked with Rexx. But Cobol.... oh boy, 17 years so far, and i think i will work with it for the rest of my life. I cannot see Cobol being replace by any other language in banking/mainframe. You can see Java, .net, a lot of languages, but they are just frontends, not really the main core language used by the mainframe. It's a simple language proper to work with financial data and big amounts of data.

[idrougge]

Originally Posted by daxb

ARexx has three special variables: RC, RESULT and SIGL

Only RESULT must be activate with "OPTIONS RESULTS". Why is it not active by default? I don`t see any benefit. Do they want to save some Ram or any other reason for it? Anyone with an explanation?

Without OPTIONS RESULTS, the result of any function call must be either assigned to a variable or the function must be called with CALL. If you do not do that, the result is sent back to the function host (ARexx) and interpreted. This may not be obvious, but a missed CALL may cause unintended behaviour under certain circumstances.

[demolition]

One thing that I have never figured out completely is how command arguments are specified on the Amiga. Example from 'format' below.

I assume the character after / specifies the type of argument, e.g. /S for a simple switch, but where can I find the full list of argument types? So it would be possible to see the above argument list from an unknown program and know exactly how to specify all arguments the correct way without trial and error.

[Jope]

Originally Posted by demolition

where can I find the full list of argument types?

Why, the style guide of course. :-)

http://wiki.amigaos.net/wiki/UI_Style_Guide_Shell

[jPV]

Originally Posted by demolition

but where can I find the full list of argument types?

Also in the official AmigaDOS manuals which you should have got with your computer/OS

Look for the "Template" in the table of contents. You can find it on page 6-8 in AmigaOS 3.1 manual and on page 88 in AmigaOS 3.9 manual, for example.

Those official manuals are a good read, I'd recommend them for everyone before they start using their Amigas, and also to refresh the memory later

[demolition]

Well, I don't think I've ever read that manual to be honest.. But it makes sense that the information would be in there. I've always figured out the arguments eventually, but never thought to look it up once and for all.. Thanks for both answers - then I also learned something today.

[daxb]

Originally Posted by idrougge

Without OPTIONS RESULTS, the result of any function call must be either assigned to a variable or the function must be called with CALL. If you do not do that, the result is sent back to the function host (ARexx) and interpreted. This may not be obvious, but a missed CALL may cause unintended behaviour under certain circumstances.

Sorry, I don`t see the context regarding my question. Some functions (mostly external ARexx interfaces) send returns only to RESULT and without OPTIONS RESULTS you don`t get the results. All other functions need to be assigned to a variable or called with CALL (if you don`t care about results) as you wrote. My question was why OPTIONS RESULTS isn`t active by default? If there isn`t a disadvantage or a situation where it must be disabled.

[idrougge]

I also fail to see a situation where you would want the result to be interpreted, it would be enlightening to see a real-use example.

[TenLeftFingers]

How do I create a jpeg that I can use as a workbench background? I got a greyscale image from the net and resized it to 1024x768 to match my screen mode. I also reduced it to 8 colours to match my pallette settings.

But at 404kb MultiView tells me there isn't enough memory (in my 8MB 'other' mem) to display it and WBPattern won't set it.

[Sir_Lucas]

Multiview is ok, but I prefer Visage.
http://aminet.net/package/gfx/show/Visage

This Gui may also be useful. Yet, I haven't used it.
http://aminet.net/package/gfx/show/visgui

[TenLeftFingers]

Thanks Sir_Lucas! I'll check those out. But I still am missing something about formatting the image correctly for a background. I have a bit-depth and resolution matched to my desktop. I even reduced the quality so the size of the file is 11kb - still no joy

[s2325]

JPG on Amiga and PC may have same extension but format may be different.

[TenLeftFingers]

Good to know, thanks.

[Lonewolf10]

Yes, the .JPG extension itself can contain 1 of 4 (or so) different formats. Not sure which ones the Amiga can handle.

[demolition]

Originally Posted by TenLeftFingers

But I still am missing something about formatting the image correctly for a background. I have a bit-depth and resolution matched to my desktop. I even reduced the quality so the size of the file is 11kb - still no joy

I think the quality doesn't matter as it has to be fully decompressed anyway before it is put into memory and used as the background. Also, I don't think that JPEG supports anything other than 24 bit colors. Convert your picture into a proper 8 color IFF file - it will also take some load off the Amiga and reduce its startup time since it won't have to do much processing of the background image to show it.