BASIC-DOS

A PCjs Retro-Programming Project

BASIC-DOS is on Twitter Project maintained by jeffpar

BASIC-DOS Protected Mode

The machine below is an IBM PC AT (Model 5170) with a 6Mhz 80286, 2Mb of memory (640K of conventional memory and 1408K of extended memory), a Color Display, a 1.2Mb and a 1.44Mb diskette drive, a 10Mb hard disk, and a DEC VT100 on COM2 for BASIC-DOS’s own debugger. It boots the BASIC-DOS Protected Mode Demo diskette.

See Protected-Mode Initialization for more details.

IBM PC AT, 2Mb RAM, 10Mb Hard Disk, CGA

Color Display
Caps
Num
Scroll
F1
F2
F3
F4
F5
F6
F7
F8
F9
F10
Esc
1 !
2 @
3 #
4 $
5 %
6 ^
7 &
8 *
9 (
0 )
- _
= +
Back
-
Num
Scroll
Tab
Q
W
E
R
T
Y
U
I
O
P
[ {
] }
↵
7
↑ 8
9
Ctrl
A
S
D
F
G
H
J
K
L
; :
' "
` ~
← 4
5
→ 6
+
Shift
\ |
Z
X
C
V
B
N
M
, <
. >
/ ?
Shift
PrtSc
1
↓ 2
3
Alt
Space
Caps
Ins 0
Del .
Esc
Tab
F1
F2
F3
F4
F5
F6
F7
F8
F9
F10
Num
Scroll
1 !
2 @
3 #
4 $
5 %
6 ^
7 &
8 *
9 (
0 )
- _
= +
Back
-
+
Q
W
E
R
T
Y
U
I
O
P
[ {
] }
↵
7
↑ 8
9
A
S
D
F
G
H
J
K
L
; :
' "
` ~
← 4
5
→ 6
\ |
Z
X
C
V
B
N
M
, <
. >
/ ?
Shift
PrtSc
1
↓ 2
3
Ctrl
Shift
Alt
Space
Caps
Ins 0
Del .
[Debugger]
PCx86 v2.26 © 2012-2026 Jeff Parsons

VT100 Terminal

VT100 Display
ON LINE
LOCAL
LOCKED
L1
L2
L3
L4
CAPS
VT100.js v3.01 © 2012-2026 Jeff Parsons

CONFIG.SYS from the BASIC-DOS Protected Mode Demo Diskette

REM Protected-mode development: no CPU=8088 line, so CPU$ uses extended memory
BUFFERS=4
SESSIONS=3
DEVICE=EXT\DEBUG.COM COM2:9600,N,8,1,VT100
SHELL=C:COMMAND.COM PATH$="C:\;C:\EXT;C:\DEMOS;C:\SAMPLES;C:\TESTS;C:\TOOLS"

Copyright (c) 2020-2026 Jeff Parsons Released under MIT License