4.2 KiB
DeskTop diassembly notes
DESKTOP.SYSTEM
A short (8k) loader program. This is likely responsible for copying the rest to a RAM card (if available), then invoking the main app.
DESKTOP2.$F1
This is large - 111k. It includes a loader, the DeskTop app (with both main memory and aux memory segments, filling everything from $4000 to $FFFF (except for I/O space and ProDOS), and still having more code - probably the disk copy code which is swapped in dynamically.
The file is broken down into multiple segments:
- segment 0: load - offset $0000, length $0580, loaded at $2000
- segment 1: aux1 - offset $0580, length $8000, loaded at $4000 (through $BFFF)
- segment 2: aux2 - offset $8580, length $1D00, loaded at $D000 (through $ECFF)
- segment 3: aux2 - offset $A280, length $0500, loaded at $FB00 (through $FFFF)
- segment 4: main - offset $A780, length $7F00, loaded at $4000 (through $BEFF)
- main $BF00-$BFFF is ProDOS buffers
- main $C000-$CFFF is I/O space
- main $D000-$FFFF is ProDOS
- segment 5: TBD - 38k so must be further subdivided. Disk Copy???
Structure
GUI Library "A2D"
AUX $4000-$8DFF is the GUI library used for the DeskTop application and (presumably) for disk copy and Selector apps (TBD).
Entry point is $4000 with a ProDOS MLI-style calling convention
- Font is at $8800
"DeskTop" Application
DeskTop application code is in the lower 48k of both Aux and Main:
- Aux $8E00-$BFFF - sitting above the GUI library
- Main $4000-$BEFF
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 $ED00-$FAFF - hole for data buffer
- Aux $FB00-$FFFF - more resources (file types, icons)
($C000-$CFFF is reserved for I/O, and main $BF page and language card is ProDOS)
Main Aux ROM
$FFFF +------------+ +------------+ +------------+
| ProDOS | | DeskTop | | Monitor |
$F800 | | | Resources/ | +------------+
| | | Buffers | | Applesoft |
| | | | | |
| | | | | |
| | | | | |
$D000 +------------+ +------------+ +------------+ +------------+
| I/O |
| |
$C000 +------------+ +------------+ +------------+
| ProDOS | | DeskTop |
$BF00 +------------+ | App Code |
| DeskTop | | |
| App Code | | |
| | | |
| | | |
| | | |
| | | |
| | | |
$8E00 | | +------------+
| | | A2D GUI |
| | | Library |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
$4000 +------------+ +------------+
| Graphics | | Graphics |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
$2000 +------------+ +------------+
| Desk Acc | | Desk Acc |
| | | |
| | | |
$0800 +------------+ +------------+
| Text | | Text |
$0400 +------------+ +------------+
| | | |
$0300 +------------+ +------------+
| Input Buf | | Input Buf |
$0200 +------------+ +------------+
| Stack | | Stack |
$0100 +------------+ +------------+
| Zero Page | | Zero Page |
$0000 +------------+ +------------+