Differences

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--- system_routines:screen_handler [2016/06/10 23:04]
ex_writer [RELAB1]
+++ system_routines:screen_handler [2016/06/10 23:05] (current)
ex_writer [Screen Handler System Routines]
@@ Line 15: / Line 15: @@
 | [[#fill|FILL]] | Fill a contiguous memory range with a constant |
 | [[#rectan|RECTAN]] | Paint a rectangle of specified size, color, and coordinates |
-| [[#relab1|RELAB1]] | Non-Magic RELABS |
 | [[#relabs|RELABS]] | Relative to absolute conversion |
+| [[#relab1|RELAB1]] | Non-Magic RELABS |
 | [[#restore|RESTOR]] | Restores area previously saved (using SAVE) |
 | [[#save|SAVE]] | Preserves specified screen area that is 'underneath' a moving pattern |
@@ Line 169: / Line 169: @@
 Lance Squire: "RELABS converts X/Y to MAGIC RAM addresses plus sets the shift bits for
 the MAGIC register."
+==== RELAB1 ====
+CONVERT RELATIVE ADDRESS TO ABSOLUTE NORMAL ADDRESS
+| Calling Sequence: | <code z80>SYSTEM    RELAB1</code> or <code z80>SYSSUK    RELAB1
+DB        (Magic register value)</code>|
+| Arguments: | A = Magic register value to combine with shift amount\\ D = Y-coordinate\\ E = X-coordinate |
+| Output: | A = Combined Magic register value\\ DE = Absolute normal address (non-Magic) |
+| Description: | This routine is identical to [[#relabs|RELABS]] except that a non-Magic address is returned, and the hardware [[hardware:magic system|Magic register]] is not set. The flopped bit is interrogated, and the flopped coordinate system is used, if optioned. |
+Lance Squire: "RELABS1 converts X/Y to SCREEN RAM addresses. Any pixel shifting is up
+to the user."
 ==== RESTOR ====