From 03929d70fdd70bd6e8bb11d0ab81edc9446199ca Mon Sep 17 00:00:00 2001 From: Joshua Bell Date: Fri, 23 Nov 2018 19:41:53 -0800 Subject: [PATCH] update README with better overlay details --- desktop/README.md | 58 +++++++++++++++++++++++++++++++++++------------ 1 file changed, 44 insertions(+), 14 deletions(-) diff --git a/desktop/README.md b/desktop/README.md index 856467a..35b954a 100644 --- a/desktop/README.md +++ b/desktop/README.md @@ -125,9 +125,49 @@ as windows are opened and closed. Interactive commands including disk copy/format/erase, file copy/delete, and Selector add/edit/delete/run all dynamically load -main memory code overlays into one or more of: $800-$1BFF, -$5000-$6FFF, $7000-$77FF, and $9000-$9FFF. When complete, any original -code above $4000 is reloaded. +main memory code overlays. When complete, any original code above +$4000 is reloaded (unless a full restart is required.) + +Several of the overlays also use a common file selector dialog overlay +`ovl4.s` ($5000-$6FFF). + +#### Disk Copy Overlay + +The Disk Copy command replaces large chunks of memory and is best +thought of as a separate application. + +The first part (`ovl1.s`, $800-$9FF) loads into main memory the other +overlays, but in turn it loads a second short ($200-byte) overlay +(`ovl1a.s`, $1800-$19FF). This then loads a replacement for the +resources in the aux language card area (`ovl1b.s`, Aux LC +$D000-$F1FF) and another block of code in main memory (`ovl1c.s`, Main +$0800-$12FF). When exiting, the DeskTop is restarted from the +beginning. + +#### Disk Format/Disk Erase + +Simple overlay: `ovl2.s`, loaded into Main A$0800-$1BFF. + +#### Selector - Delete Entry / Run Entry + +Simple overlay: `ovl3.s` ($9000-$9FFF). + +#### Selector - Add Entry / Edit Entry + +Also uses `ovl3.s` ($9000-$9FFF) but additionally uses overlay +`ovl7.s` ($7000-$77FF) and the file selector dialog `ovl4.s` +($5000-$6FFF). + +#### File Copy + +Overlay `ovl5.s` ($7000-$77FF), uses file selector dialog `ovl4.s` +($5000-$6FFF). + +#### File Delete + +Overlay `ovl6.s` ($7000-$77FF), uses file selector dialog `ovl4.s` +($5000-$6FFF). + ## Memory Map @@ -212,14 +252,4 @@ $0100 +-------------+ +-------------+ $0000 +-------------+ +-------------+ ``` -#### Disk Copy Overlay - -The Disk Copy command replaces large chunks of memory and is best -thought of as a separate application. - -The first part (`ovl1.s`) loads into main memory the other overlays, -but in turn it loads a second short ($200-byte) overlay (`ovl1a.s`). -This then loads a replacement for the resources in the aux language -card area (`ovl1b.s`) and another block of code in main memory -(`ovl1c.s`). When exiting, the DeskTop is restarted from the -beginning. +Memory use by the Disk Copy overlay is not shown.