Yo guys ... I had a SCPH-10000 with HDD for a long time ... A friend who plays FFXI lost his SCPH-39000 (it blew the CD/DVD drive without explanation and then he couldn't install the FFXI expansion disc, at the time it was Rise of the Zilart). I sold him my SCPH-10000 and took his internal HDD kit in exchange for my external one.
About the V0 don't working when the HDD support stuff on MC is installed, as you guys already mentioned the V0 bios is incomplete and has no DVD driver, HDD support modules and such. The only way to have them loaded is off the memory card. The SCPH-18000 has the HDD support and DVD driver built in. Since this data is installed on the memory card, older modchips are unable to patch them as they will be loaded to the PS2 memory after the modchip is done with patching the system modules that boot discs. It means that having a HDD installed on a V0 will defeat your modchip. Same happen with the same old modchips in a V1-V7 PS2 with a official HDD installed. the browser updates will overwrite all the patching and the PS2 is back to the "read only originals state" regardless of region. Newer chips with official HDD support or ATAD patching for sony browser, like the MI or DMS3/4, install a small "hook" or "trojan horse" to re-patch everything once the browser pudates are in place. Same thing happen with DVD multi region patch.
SCPH-10000_GH-001 SCPH-15000_GH-003 SCPH-18000_GH-008 SCPH-30001_GH-005 SCPH-30000_GH-016(V4) SCPH-30001_GH-010(V4)
2xSCPH-10190, 2xSCPH-10350, 2xSCPH-10280
"**** j0 hackers!"
-Sjeep (As seen on TOXIC OS ELF...)