This is the README file for utility VRMAREA.BIN
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This utility is moving rectangular shaped data box from the
GR8NET RAM to the VRAM. For example, in SCREEN 8 mode (when
one byte equals to one pixel) utility displays rectangle on
the screen of required size from data in the GR8NET RAM, in
other modes one byte may not be equal to one pixel thus
special care should be taken handling those modes properly
as utility only moves bytes, and not parts of bytes and does
not perform any logical functions on pixels.

Usage
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Executable code is relocatable, thus you can load it using
BLOAD"VRMAREA.BIN",&h1000
which means that executable will be loaded into the address
D000 (by default it loads into C000). Then application should
fill in the properties of the rectange and image, in paricular:

+0	(byte)	x-position of the rectangle
+1	(byte)	y-position of the rectangle
+2	(byte)	x-size of the rectangle
+3	(byte)	y-size of the rectangle
+4	(byte)	screen width; 0 means screen width is 256 bytes
+5	(byte)	VRAM page; 0=first 64K, 1=second 64K
+6	(word)	VRAM base address; e.g. pattern layout from NAMBAS (F922)
+8	(byte)	GR8NET RAM page of the image (e.g. loaded with NETBLOAD)
+9	(word)	GR8NET RAM address within 6000-7FFF window (GR8NET bank 2)
+11	(byte)	GR8NET slot ID to be used, can be ontained through
		index #1 I/O register of the respective GR8NET adapter

After structure is loded, set execution address to offset +16
DEFUSR=&HD016
ensure that image is loaded, set desired SCREEN mode, and run
A=USR(0)

NOTE: after each run application will need to restore y-size of the
rectangle because utility uses it for tracking vertical display
progress and after run it is always equal to 1.

Format of the image
-------------------
Image should not have any headers, lines should be arranged
continuously without any breaks or spacing, thus image of 21*15
rectangular size will occupy 315 bytes of the GR8NET RAM.

Location of the utility
-----------------------
Utility and this readme file are located in
http://www.gr8bit.ru/software/binaries/ subdirectory.

VRMAREA.BIN is developed by Eugeny Brychkov 25-Aug-2016.

End of VRMAREA.TXT