Commodore A690

[Oldsmobile_Mike]

Somebody (not me) is selling A690 wich is most likely prottype of A590?

The A590 is a hard drive.  The A690 is a CD-ROM drive.  Totally different.  A690 makes your A500 basically 99% CDTV compatible.  It's a good CD drive solution for A500's if you already have some other form of hard drive expansion (such as AdIDE, etc.).

[Oldsmobile_Mike]

The A690 is a prototype of the A570.  See these links for an explanation of the weird numbering scheme:

http://www.commodore-amiga-retro.com/amiga/amiga_scuzz68.htm

http://en.wikipedia.org/wiki/Amiga_A570

IMHO if you want a CD drive for your A500 look for an A570 or external SCSI model.  A690 is more of a collector's item, you'll probably have trouble getting it to work 100%.

[Oldsmobile_Mike]

Going out on a limb, you'd probably need a rom from an A570.  But who knows?  

[Oldsmobile_Mike]

I belive that newer roms for CDTV are actually from A570?

I really don't know anything about this, so again, just going out on a limb, this link here:  http://amiga.resource.cx/photos/photo2.pl?id=a570&pg=1&res=hi&lang=en  seems to show a chip marked "Commodore-Amiga 391298-01 c1992 V2.30 9232 D" in the rom position.

I tried to google up a high res picture of a CDTV motherboard to see if I could spot an identical chip on it's motherboard.  I wasn't having much luck, but I came across this thread:  http://eab.abime.net/showthread.php?t=61625  post #6 says a CDTV uses two ROM chips.  Same version number, 2.30 (I thought that number sounded familiar, hence why I looked), but it looks like they're split into a pair in CDTV.

Also looked at the high res pic of the A690 motherboard (here:  http://www.bigbookofamigahardware.com/bboah/media/download_photos/a690_2_big.jpg  ).  A real spaghetti mess of wires on the bottom.  I'd avoid that thing like the plague, again just IMHO.