if plpvhd will have some more flexible options many people from
reboot.pro, msfn.org or vogons and other old-school(
os2musem) will happily use plpvhd.
Many retro gaming users or legacy industry administrators are need it.
Not all aplications are running under virtual machines or API emulators in PM-mode/DPMI Extender.
They need true "Real mode" and Realtime OS without tasks schedullers.
Look on 1th example - from life...If you are small metalworker and you have old
FANUC CNC Lathe which has only DOS16/realmode program for it from 1980's
Which need direct access to LPTport for controlling servos/ board like Mach3 SW.
You have only few options:a) Vboot (comercial)
b) Chinese bootloaders (will you use it?) me not.
c) BOOTMGR (complicated bcdedit) impossible remember UUIDs and config!
d) plpvhd tiny simple out of box loaderMachine operators are old people they don't like new windows systems and learn new programs.
2nd scenario:You have dos program and old LPT ZIPdrive and ELCOM EEPROM programmer
and you need use it 2-3times per year and you don't want kick it to trash. So simple boot freeddos.vhd make EEPROM copies and return to your primary OS. only simple reboot needed
Flashing SW for
Nokias playing.
I helped to one man who is repairring eletronics he has copy of EEPROMs for many many devices car radio or PLC.
Many industry based systems SIEMENS/SIMATICs are still running on very old HW.
Also in automotive (VW really I saw it!), fabrication or in BANK/finnance sector are using OS2/Warp or OS2/Aurora and COBOL based interbanking exchange systems! AS/400 and other obscure legacy systems.
My last experience:I have problem with HDD last month and i have there WinXP in VHD
i was able boot WinXP and recover primary OS Win7 partition after HW fail
this
old machine has no USB boot support only FDD/ATAPI or HDD
and also
crippled BIOS boot from ATAPI is not able boot Win7/VIsta bootloader from DVD!I have to use workaround like mcGyver....
CDROM boot (isolinux) -> Grub4Dos (very flexible) with shell
find on disk PloP and enable USB 2.0 support and boot from USB dongle

where was Win7 installer.
And this way i found plpvhd ...
I dediced try it vs. BOOTMGR (win7 boot manager).
BOotMGR has binary \BOOT\bcd config and edit require working OS with bcdedit.exe.
Thats in recovery/emergency situations really ODD/sux....
It's much better boot GRUB4DOS 0.4.6c (much better than v0.4.5)
such like non-casesensitive paths, autocomplette on TAB key etc...
quite powerfull shellAnd this is the reason why will be fine has option tell to plpvhd
load me please DISK_D\VHDIMG\freedos.vhd or C:\RESCUE.VHD\winxp.vhd
Windows bootloader has this - hidden feature implemented such like this
http://reboot.pro/topic/7502-windows-recovery-console-in-grub4dos/It's writting on fixed memory location special string.
plpvhd.bin may check "
PLPVHD" signature at memory location
it's only (6bytes) 3x times cmp ax, value if is not present bootloader will go in interactive mode (manual filelisting)
If special string exist it will try get next parameters such like partition and filename.
This is same as APPEND in isolinux parameters for kernel
and this is giving big flexibility.
I want only describe what people are missing and how to implement
easy with big step forward with minimal attack on source code.
Why this parameters are GOOD to HAVE? you may prepare simple
boot menu from GRUB/GRUB4DOS/GRUB2 and make booting easier
also for kids which may play old DOS games without waitting on Father
which will start OS + GAME
btw GRUB has failover features if boot fail it will activate alternative commands machine will load another VHDfile...
(important on production machines such like CNC Lathe Computer)But adding choose another partition and filter deleted files is fine.
I am happy now probably later you will add parameters during COVID lockdown
