Tandy 1000 HX Technical Reference Manual page 418

MS-DOS Memory Map
Notes:
1. Detailed description in following pages.
2. Approximate address; subject to change.
3. "X" is defined as follows:
4. Video memory accessed through the B800:0 window for all
video modes.
28
Memory Size
128K
256K
384K
512K
640K
768K
X Value
1
3
5
7
9
B
HEXADECIMAL
STARTING ADDRESS
(SEGMENT:OFFSET)
000:00
000:80
0040:00
1
0050:00
0070:00
0190.00
2
05B0:00
2
X800:00
3
XC00:00
3
B800:00
4
F000:00
FC00:00
DESCRIPTION
BIOS Interrupt Vectors
Available Interrupt Vectors
ROM BIOS Data Area
MSDOS and BASIC Data Area
I/O.SYS Drivers
MS-DOS
Available to user
Video RAM in 32K video modes
Video RAM in 16K video modes
Video RAM Window (32K)
Reserved for system ROM
System BIOS ROM