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notes on memory usage

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Joshua Bell 2019-01-19 10:33:38 -08:00
parent 1e80673273
commit 443be43396
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desktop/README.md
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@ -79,7 +79,7 @@ run.
`mgtk.s`
Aux $4000-$851E is the [MouseGraphics ToolKit](../MGTK.md) - a
Aux $4000-$8580 is the [MouseGraphics ToolKit](../MGTK.md) - a
GUI library used for the DeskTop application.
Since this resides in Aux memory, DeskTop spends most of its time
@ -96,28 +96,42 @@ data.
DeskTop application code is in the lower 48k of both Aux and Main:
* Aux $851F-$BFFF - sitting above the GUI library (`desktop_aux.s`)
* Aux $8580-$BFFF - sitting above the GUI library (`desktop_aux.s`)
* Main $4000-$BEFF (`desktop_main.s`)
...and in the Aux language card area (accessible from both aux and
main code) are relays, buffers and resources:
* Aux $D000-$ECFF - relays and other aux/main helpers, resources (menus, strings, window)
* Aux $D000-$D1FF - main-to-aux relay calls
* Aux $D200-$ECFF - resources (menus, strings, window)
* Aux $ED00-$FAFF - hole for data buffer - entries for each icon on desktop/in windows
* Aux $FB00-$FFFF - more resources (file types, icons)
($C000-$CFFF is reserved for I/O, and main $BF page and language card is ProDOS)
`desktop_res.s` defines these common resources. It is built as part of
`desktop.s`. Early in the build process it is also built as part of
`desktop_res_build.s` which is processed to produce `out/desktop_res.inc`,
which is used by the overlay sources.
`desktop.s`.
Aux $1B00-$1F7F holds lists of icons, one for the desktop then one for up
to 8 windows. First byte is a count, up to 127 icon entries. Icon numbers
map indirectly into a table at $ED00 that holds the type, coordinates, etc.
Aux $1F80-$1FFF is a map of used/free icon numbers, as they are reassigned
as windows are opened and closed.
The DeskTop code in Aux primarily implements the actual desktop GUI,
drawing file icons in windows, volume icons on the desktop, handling
selection and dragging, and tracking icons in windows; this code is
implemented as a library with MLI-style calls. The code in Main
handles the bulk of the application logic.
When running, lower memory use includes:
* Main $800-$1BFF is used as scratch space for a variety of routines.
* Main $1C00-$1FFF is used as a 1k ProDOS I/O buffer.
* Aux $0800-$1AFF is a "save area"; used by MGTK to store the background
when menus are drawn so it can be restored without redrawing. The
save area is also used by DeskTop to save the background for alert
dialogs, and icon outlines when dragging.
* Aux $1B00-$1F7F holds lists of icons, one for the desktop then one for up
to 8 windows. First byte is a count, up to 127 icon entries. Icon numbers
map indirectly into a table at $ED00 that holds the type, coordinates, etc.
* Aux $1F80-$1FFF is a map of used/free icon numbers, as they are reassigned
as windows are opened and closed.
### Overlays
@ -202,7 +216,7 @@ $8E00 | | | Entry Point |
| | | |
$8800 | | | Font |
| | | |
$851F | | +-------------+
$8580 | | +-------------+
| | | MGTK |
| | | |
| | | |