Subj : CIA Chip hack
To   : Allen Prunty
From : Dave Drum
Date : Mon Jun 06 2016 07:44:24

-=> Allen Prunty wrote to Dave Drum <=-

 AP> I don't know if this will fix it but I have access to a couple of
 AP> broken C64s that may fit the bill.

 AP> Allen

 AP> ---

 AP> This text file describes what to do in order to fix Amiga 500(if one
 AP> of the CIA's is dead) with the parts taken from broken Commodore 64.

 AP> I SHALL STATE THAT THIS IS A HACK, ITS A HACK! ITS A HACK!!! HOWEVER
 AP> CONFIRMED, IT WORKS FOR ME.

  8<------- EDITING BEING DONE HERE ----->B

 AP> In C 64 there are also two CIA's and they are at (locations according
 AP> to new pcb) U1 and U2 they have printed 6526B on them. So now you just
 AP> need to desolder one of them or both, clean up the pins and put in your
 AP> Amiga in place of B one. The pinouts are same so nothing can go wrong.

Unless you leave the hot iron on them too long. Many of the chips from the C=64 era were VERY heat sensitive. And never mind how I know that.

 AP> There are several mothods to strip the chip from pcb. I used ordinary
 AP> soldering iron and the simple sucking device to pick the tin. If you
 AP> got no such tools then you may use simple handy gas burner directly on
 AP> the pins from some distance. But before doing this set the nozzle not
 AP> to cut but to distribute the heat smoothly. Then try to toggle the
 AP> burner form one side to another and if you notice tin melting grab the
 AP> ic - be cautious its hot! Also, dont heat the chip too long!

As I said above.  Bv)=

 AP> DOWNSIDES:

This, of course, if for an A-500. It seems to me that I was told the A-4000 has soldered in CIAs - and it may well be touchier on its specs. I did a newbie trick of plugging a printer into the parallel port whilst the Miggy was "live". And then it was dead. FEH. Stupid bastard.

Anyway - thanks for the info. I have several C=64s laying about. Most work .... but, how many 64s does a sane person need?

.... "All constants are variables." - Murphy's Law of Mathematics

--- BBBS/Li6 v4.10 Dada-2
 * Origin: Prism bbs (1:261/38)

.