Ms-Dos Memory Map - Tandy 1000 SL Technical Reference Manual

BIOS Services
MS-DOS Memory Map
Hexadecimal
Starting Address
(Segment:Offset)
ooo:oo
000:80
0050:OO
0070:OO
05BO:002
X80O:0O3
B800:004
E000:OO
F000:OO
FC00:OO
oo40:oo1
0190:oo2
XCOO: 003
Description
BIOS Interrupt Vectors
Available Interrupt Vectors
ROM BIOS Data Area
MSDOS and BASIC Data Area
I/O.SYS Drivers
Available to user
Video RAM in 32K video modes
Video RAM in 16K video mode
Video RAM Window (32K)
ROM Drive
Reserved for system ROM
System BIOS ROM
MS-DOS
Notes:
Detailed description in following pages.
Approximate address; subject to change.
X is defined as follows:
Memory Size
X Value
128K
1
256K 3
384K 5
512K 7
640K
9
768K B
Video
memory
accessed
through the B800:O window for
all video modes.
51.