A500 1MB Chip mod, working with card removed?

[TjLaZer]

I had always thought, that after you did the 1MB Chip RAM mod, you always had to have the 512k RAM card installed for the A500 to even work.  Since it was now looking for that extra 512k to provide for the 1MB Agnus and Chip RAM.  Well I was working on my A500 and I accidently tried to power it up with the A501 removed, and it worked!  It, of course, only had the 512k Chip RAM.  

Just thought I would post this, since I am such a retro geek.  :banana:

[TjLaZer]

Nope, been working on Amigas since 1987 too.  I abandoned the "console" Amiga in 1995 though. (Got myself a mil spec A2000 since I was in the Air Force, lol) I recently, for my collection, aquired the consoles.  I did the 1MB Chip mod a few months back.  I had done it originally in 1991 to my A500 back then.  Now that I think about it, that A500 did not work with the A501 removed.  I think it was a Rev 5A mobo, and this mobo is a Rev 6.  Is this the reason I wonder?