OSWORD &2E

&2E 46  Read PRISMA base screen visible origin			Prisma
	On exit:
		XY+0..1=X coordinate
		XY+2..3=Y coordinate

	The coordinates are returned with respect to the current graphics
	origin. The coordinate returned is the bottom left hand corner
	of the BASE screen when the LOWER screen is disabled. When
	enabled, the LOWER screen will cover this point.

	The BASE screen co-ordinate in the bottom left hand corner of the
	visible screen will vary with the current zoom factor and with
	panning and tilting commands. The OSWORD &2E call can be used to
	return this co-ordinate.

PRISMA calls

• OSWORD &28 Read PRISMA information table
• OSWORD &29 Read PRISMA pixel value
• OSWORD &2A Read PRISMA logical screen size
• OSWORD &2B Read PRISMA colour palette
• OSWORD &2C Send VDU sequence direct to PRISMA
• OSWORD &2D Read last two PRISMA graphics cursors
• OSWORD &2E Read PRISMA base screen visible origin
• OSWORD &2F Read PRISMA graphics origin
• OSWORD &30 Read PRISMA interrupt status
• OSWORD &31 Direct call to PRISMA command
• OSWORD &32 Read position of PRISMA-3 roller screen
• OSWORD &33 Read/Write PRISMA overlay or nonvolatile memory

See Also

• http://mdfs.net/Docs/Comp/BBC/Oswords

Jgharston (talk) 19:54, 25 October 2015 (UTC)