# 3270 Screen Sizes, 62x160, Light Pen and APL | WND Software Docs

Source: https://wndsoftware.com/docs/screen-sizes

### 3270 screen sizes, light pen and APL

Mainframe sessions can use the four standard models, the IBM 3290’s 62×160, any size up to 255×255, or the largest size that fits the window.

Choose the size under Screen on the connect page. Models 2 to 5 connect as they always have. 62×160 and other sizes connect as an `IBM-DYNAMIC` terminal, so the mainframe reads the size from the terminal and the application needs a logon mode that accepts it. If the mainframe refuses, WND Terminal falls back to the largest model that fits and says so.

On a small screen, swipe the table to read all columns.


| Screen | Size | Connects as |
| --- | --- | --- |
| Model 2 | 24×80 | `IBM-3279-2-E` |
| Model 3 | 32×80 | `IBM-3279-3-E` |
| Model 4 | 43×80 | `IBM-3279-4-E` |
| Model 5 | 27×132 | `IBM-3279-5-E` |
| IBM 3290 size | 62×160 | `IBM-DYNAMIC` |
| Other size | Any rows and columns from 24×80 to 255×255 | `IBM-DYNAMIC` |
| Fit the window | The largest size from 24×80 to 62×160 that fits the tab | A model or `IBM-DYNAMIC` |


### Choose a size

Pick one under Screen  on the connect page. IT sets it per connection with `ScreenSize`, such as `"62x160"`, `"50x100"` or `"fit"`. In Group Policy, add `|62x160` or `|size=fit` to the connection’s line. IBM i sessions have 24×80 and 27×132.


### How other sizes connect

A size the four models don’t have connects as an `IBM-DYNAMIC` terminal. z/OS’s TN3270 server accepts that type for terminals of any size, over TN3270 and TN3270E. The mainframe reads the size from the terminal, so the application needs a logon mode that takes the size from there. On most z/OS systems that’s `D4B32XX3` or `SNX32705`. Ask your mainframe team which one your applications use.

If the mainframe refuses `IBM-DYNAMIC`, WND Terminal connects with the largest model that fits instead, and a note says so.


### Fit the window

Fit the window  picks the largest size that fits the tab when the session connects, at the text size set in the Display menu. It stays between 24×80 and 62×160, so the text stays readable.


### Big screens stay readable

On big screens the rows sit a little closer together, so the text can be larger. When the screen scales to the window, the text never gets smaller than 11 pixels. The screen scrolls instead. Printing a screen wider than 132 columns makes the text small enough to fit the page.

Everything that reads the screen works the same at any size. That includes copy, Capture all pages, Fill from Excel, Modern view, Explain this screen, Ask WND, guides, session recordings and Send to help desk.


### Light pen and Cursor Select

Fields the mainframe marks as light-pen detectable work as they did on a 3270 with a light pen. The first character of the field says what selecting it does.

On a small screen, swipe the table to read all columns.


| First character | Selecting the field |
| --- | --- |
| `?` | Turns into `>` and marks the field to go with the next Enter or PF key. Selecting it again undoes it. |
| `&` | Sends Enter. |
| A blank | Sends the light pen attention, with the address of each marked field. |

Cursor Select  (Ctrl+F9, as in PCOMM) selects the field at the cursor. It’s also in the Ctrl+K palette and in keyboard maps. A click on a `?`, `>` or `&` field selects it too. To turn clicking off, clear Click selects light pen fields  in the Display menu. Cursor Select is a mainframe key, and IBM i sessions refuse it.


### APL

Ctrl+F8 turns the APL keyboard on and off, as in PCOMM, and the status line then says APL. The layout follows the IBM 3278 APL keyboard. Shift and a key types its APL symbol, such as Shift+R for ⍴ and Shift+I for ⍳.

APL symbols go to the mainframe as APL characters. Symbols you paste, or type through a keyboard map, go the same way when the host’s code page doesn’t have them, so pasting `⍴⍳10` works without APL mode. Ctrl+K > Keyboard maps > Make the APL map  makes a map in which Alt and a key types its APL symbol.

APL is on unless IT turns it off with `AllowAPL` = false, or Turn off typing APL  in Group Policy. APL characters the mainframe sends still show.


### Questions


#### Does WND Terminal support 62x160 screens?

Yes, for mainframe sessions. 62x160 is the IBM 3290's size. It connects as an IBM-DYNAMIC terminal, so the application needs a logon mode that takes the size from the terminal.


#### What happens if our mainframe doesn't accept IBM-DYNAMIC?

WND Terminal connects with the largest standard model that fits, and a note on the session says so.


#### Can people type APL?

Yes. Ctrl+F8 turns on the APL keyboard, and pasted APL symbols are sent as APL characters. IT can turn APL off with AllowAPL = false.

Technical reviewer: [Albert Joseph](https://wndsoftware.com/authors/albert-joseph), WND Software.