QDOS Internals

Anything you never knew you wanted to know about the Sinclair QL.

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Memory Map

The original QDOS memory map is shown below. This is still valid on the old black boxes, but Trump Cards, Gold Cards, Super Gold Cards, Aurora etc may/will have changed things about. I currently have no information on these devices so I cannot document them here. I have requested details using the QL newsgroup and as information arrives, I shall add it here.

From addressTo addressUsage
$C0000 $FFFFF Peripheral ROMS - up to 16 each a maximum of 16Kb in size.
$40000 $BFFFF Expansion RAM up to 512 KB.
$30000 $3FFFF Remainder of original 128Kb RAM
$28000 $2FFFF System variables & screen 2 - total 32K
$20000 $27FFF Screen 1 - 32 Kb
$1C000 $1FFFF External I/O
$18000 $1BFFF Internal I/O
$10000 $17FFF External I/O
$0C000 $0FFFF External ROM slot - 16Kb
$00000 $0BFFF Internal 48K ROM
qdosmsq/memory/map.txt · Last modified: 2008/03/17 16:19 by norman