Re: Where do I start?

On 5/23/2010 6:01 PM, Ron Hudson wrote:
> What would you have to do, proportionally place everything rather
> than have a static format you could just throw at the screen?

It depends. For many applications, you can retain 80 charter 
lines, but write as many as the session has (24, 32, 43 for 
models 2-4, 27 for model 5, 52 for 3290). Custom sizes are also 
possible, but at this point you do not want to get involved with 
that.  Some other functions (e.g, a storage display) can check 
the screen width and adapt on the fly.

For planning, the basic thing to remember is that distinct 
fields (input or output) require one extra byte on the display 
to define the characteristics, so your six fields of length 72 
actually would need 78 spaces per line. To make life 
interesting, the display does not match the buffer; e.g., 
defining a field requires a minimum of two bytes (Start Field 
order + attributes: input, output, non-display), and may have 
more to define color and high-lighting, etc. And you need to 
worry about cursor management - will you always position the 
cursor to the same field, or will it vary depending on what the 
user does or doesn't type in.  There is enough interesting stuff 
to learn to keep you busy all summer, and then some. The "bible" 
for this is the IBM - 3270 Data Stream Prgm. Ref. (GA23-0059-07)

http://www-01.ibm.com/support/docview.wss?uid=pub1ga23005907



Gerhard Postpischil
Bradford, VT