Amiga 500 rev 7, why it is from 1988?

[utri007]

Hello,

here is rare rev7 Amiga 500 motherboard. It is manufactured 1988, when there was still rev 5 and rev 6 motherboards on sale.

Rev 6 was sole for something like 1990, so does anyone know why rev 7 is from 1988 and was it pulled back?

https://1drv.ms/u/s!AsdbQ2CKZfHPhLh5y82Gk2w3_Zp8aA

[utri007]

I'm not a original owner, but 1mb chip mod is made by me. Case and mobo s# doesn't match.

This is NTSC machine and I have not idee how it ended up to here Finland.

[utri007]

Here better pictures.