Amiga 500 Rev 5. and ECS chip set...??

[Rabbi]

Don't forget the following mods are 100% needed if you're going to upgrade a version 5 A500 motherboard Kickstart ROM:

1) Bend pin #31 up 180 degrees & solder an insulated wire connecting it to pin #21
2) Solder an insulated wire onto pin #1 that terminates into the socket where pin #31 would've gone.

I didn't do this originally.  I plugged the ROM in without this modification & must've damaged a chip or something because there's a column of spurious lines in the column whereever the cursor is.  Also in the 3.1 boot-up screen, there's a flashing solid thin blue line at the bottom of the screen when the animation of the disk being inserted plays.  Can someone tell me what I damaged?  Agnus??  I had another Ver 5 A500 & plugged that 3.1 ROM after I removed it from the "damaged" rev 5 A500, modified that 3.1 ROM kernal chip, & inserted it into a different A500 rev 5 one & it seems fine, the ROM kernal being undamaged.

It looks like I bought the last of the Super Denise from what Vesalia had in stock.  You can use a VGA monitor on the A500 once you get it to boot up in Euro 72 Productivity mode,  but 4 colors is a bit lacking.

EDIT:  BTW, the pin #1 starts on the top left side by the notch, proceeding counterclockwise around the chip.

[Rabbi]

That has nothing to do with anything ROM connected. Sounds like something on the chip bus. Have you checked power levels?

Original C= ROMs came with a simple resistor installed between pins 1 & 31 to rearrange A17. I'm pretty sure nothing breaks if no modifications have been done, the system simply won't boot up.

The strange thing is if I put back the 1.3 ROMs, no such problem occurs with that.  The old 1.3 arrow cursor display correctly w/out a column of vertical lines in the cursor "column".

Could it possibly be that I also changed out the Denise chip to the ECS Super Denise?  It still has the OCS Agnus, 8370; whereas the other A500 that I got working w/out the vertical column lines that follow the cursor in 3.1 ROMs has an NTSC ECS Agnus, 8372A.

I also swapped out the MC68000 & put in an MC68010P8 into both.  It's darned hard to find anyone selling 68010s, too.

I'm eventually going to try swapping suspected chips between the one A500 that works & the other A500 that gets vertical lines in the cursor column, both 3.1 upgrades & both rev. 5 m/b's to see if I can determine the problem that way.

How & where would I check the power levels?  I've got a VOM.

[Rabbi]

An '010 won't cause anything of the sort either. The Hires Denise might be a good lead - ECS modes won't work w/o a newer Agnus anyway. Possibly the 3.1 ROM tries to activate some trickery.

Problem solved!  If you upgrade the Kickstart ROM chip to 3.1, replacing an OCS Denise with an ECS Denise - yet retaining an OCS Agnus - yields the result of a column of vertical lines in the cursor's "column".  I found this out by replacing the ECS Denise with the OCS Denise that I swapped out.  Once I put back the OCS Denise w/the OCS Agnus, the problem disappeared.