Following the guide @ Sample usage of a harddisc image in DOSBOX I could install MS-DOS 6.22 in DOSBox;
When a floppy disk is mounted it is read as a 360K floppy disk.
I am using DOSBox 0.65 on WinXP Pro

I tried launching MSD and it recognizes a 360, 5,25" floppy (drive?).
At the very moment it is of no use for me to have MS-DOS 6.22 with working virtual 1.44Mb floppy reader, it is simply for pure speculation but thanks to all those will reply or address me to the right documentation.

[sdl] fullscreen=false fulldouble=false fullresolution=original windowresolution=original output=surface autolock=true sensitivi […]
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[sdl]
fullscreen=false
fulldouble=false
fullresolution=original
windowresolution=original
output=surface
autolock=true
sensitivity=100
waitonerror=true
priority=higher,normal
mapperfile=mapper.txt
usescancodes=true

[dosbox]
language=
machine=vga
captures=capture
memsize=256

[render]
frameskip=0
aspect=true
scaler=normal3x

[cpu]
core=full
cycles=10000
cycleup=500
cycledown=20

[mixer]
nosound=false
rate=22050
blocksize=2048
prebuffer=10

[midi]
mpu401=intelligent
device=default
config=

[sblaster]
sbtype=sb16
sbbase=220
irq=7
dma=1
hdma=5
mixer=true
oplmode=auto
oplrate=22050

[gus]
gus=true
gusrate=22050
gusbase=240
irq1=5
irq2=5
dma1=3
dma2=3
ultradir=C:\ULTRASND

[speaker]
pcspeaker=true
pcrate=22050
tandy=auto
tandyrate=22050
disney=true

[bios]
joysticktype=2axis

[serial]
serial1=dummy
serial2=dummy
serial3=disabled
serial4=disabled

[dos]
xms=true
ems=false
umb=false

[ipx]
ipx=false

[autoexec]
@echo off
mount y ..\DOS\DOS622
imgmount c y:\DOS622.IMG -size 512,63,16,20 -fs fat
imgmount a y:\DOS622_1.IMA -t floppy
boot y:\DOS622.IMG