Need expert advice on installing KS 3.1 on A500 rev. 5

Benighted · 18 August 2009, 21:04

Hi,

Please observe my other thread. I've made a new one since this is a separate topic. I hope the mods are ok with that.

Now, on to the issue at hand. I received the KS 3.1 rom chip from Vesalia yesterday. The package was in fine order, and I'm ready to install it. Only problem is that I do not have any experince with these kind of hacks, and a couple of hints from EAB would be very much appreciated.

I have the manual and it states:
"Rev 3 and 5 only:
You have to solder a connection from pin 1 to pin 31 of the socket. Please make sure that pin 1 remains accessible. Then you must solder a connection from pin 21 to pin 31 of the ROM chip. Important: Please bend pin 31 up so that it doesn't have contact to the socket when the chip is inserted."

How do you make a connection like this? Are there any good websites that explain this (with pics?

)

I have also a thread over at Amibay regarding this.

alexh · 18 August 2009, 23:40

It is very easy. If you are lucky the person who provides you with your KS3.1 EPROM can do most of the mod for you.

You bend up pin 31 on the EPROM out to 90' so that it does not go in the socket when you insert the EPROM into the Amiga. Taking great care not to snap it off.

Using solid core wire you solder one end of the wire to the top of the leg of pin 1 (on the EPROM) and feed the other bare end into the Amiga motherboard ROM socket where pin 31 should have gone. Using solid core cable enables you to do this easily.

Then solder a very short bit of wire from pin 21 (across the back of the EPROM) to the leg of pin 31 which is bent up 90'.

Voila.

Benighted · 22 August 2009, 20:05

Silly q: How do you identify the pin numbers? Start counting from the top left?

prowler · 22 August 2009, 20:11

See this page. In particular, the paragraph headed Pin numbers.

All ICs are numbered similarly.

Benighted · 24 August 2009, 10:36

Quote:

Originally Posted by alexh

Using solid core cable enables you to do this easily.

What's the defintion of a solid core cable? What can I use?

alexh · 24 August 2009, 11:04

Solid core cable / wire is just a type of insulated electrical wire. The core is a single strand of copper instead of 10's of thinner ones (multistrand).

Choose your diameter carefully too big and it wont fit in the socket without shaving, too small or it will just slip out. Something around 0.6mm should do.

If in doubt, take the EPROM chip with you to the electronics store.

Benighted · 24 August 2009, 11:41

Ok, will do! Thanks a bunch for the quick and useful reply!

Benighted · 05 October 2009, 21:39

Wow, It really took time before I got myself to try this.

I've tried a couple of times, but It's black screen all the way. No red or green LED either.
I had to adjust all the pins on one side to make them fit in the socket, and I found it a bit hard to get the wire to stay in. It's probably too thin as you say. During my first attempt I used too much solder which made it impossible to get the rom into the socket. I fixed that, but still no joy.

I've put in the old 1.2 KS and I get the boot screen. Although the floppy drive behaves kinda weird. It seems random when it spins. I also can't get it to read any disks. Pheww...

Shadowfire · 05 October 2009, 22:22

Did you ground yourself before fiddling with the chip? That same page has a title called Static Precautions, if you're not careful you can destroy the IC's just by touching the pins. Can you snap a photo of what you've done so far, installed in the system?

18 August 2009, 21:04	#1
Benighted Amiga = Metal! Join Date: Jul 2009 Location: Stavanger / Norway Posts: 92	Need expert advice on installing KS 3.1 on A500 rev. 5 Hi, Please observe my other thread. I've made a new one since this is a separate topic. I hope the mods are ok with that. Now, on to the issue at hand. I received the KS 3.1 rom chip from Vesalia yesterday. The package was in fine order, and I'm ready to install it. Only problem is that I do not have any experince with these kind of hacks, and a couple of hints from EAB would be very much appreciated. I have the manual and it states: "Rev 3 and 5 only: You have to solder a connection from pin 1 to pin 31 of the socket. Please make sure that pin 1 remains accessible. Then you must solder a connection from pin 21 to pin 31 of the ROM chip. Important: Please bend pin 31 up so that it doesn't have contact to the socket when the chip is inserted." How do you make a connection like this? Are there any good websites that explain this (with pics? ) I have also a thread over at Amibay regarding this.

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18 August 2009, 23:40	#2
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,337	It is very easy. If you are lucky the person who provides you with your KS3.1 EPROM can do most of the mod for you. You bend up pin 31 on the EPROM out to 90' so that it does not go in the socket when you insert the EPROM into the Amiga. Taking great care not to snap it off. Using solid core wire you solder one end of the wire to the top of the leg of pin 1 (on the EPROM) and feed the other bare end into the Amiga motherboard ROM socket where pin 31 should have gone. Using solid core cable enables you to do this easily. Then solder a very short bit of wire from pin 21 (across the back of the EPROM) to the leg of pin 31 which is bent up 90'. Voila.

22 August 2009, 20:05	#3
Benighted Amiga = Metal! Join Date: Jul 2009 Location: Stavanger / Norway Posts: 92	Silly q: How do you identify the pin numbers? Start counting from the top left?

22 August 2009, 20:11	#4
prowler Global Moderator Join Date: Aug 2008 Location: Sidcup, England Posts: 10,300	See this page. In particular, the paragraph headed Pin numbers. All ICs are numbered similarly.

24 August 2009, 11:04	#6
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,337	Solid core cable / wire is just a type of insulated electrical wire. The core is a single strand of copper instead of 10's of thinner ones (multistrand). Choose your diameter carefully too big and it wont fit in the socket without shaving, too small or it will just slip out. Something around 0.6mm should do. If in doubt, take the EPROM chip with you to the electronics store.

24 August 2009, 11:41	#7
Benighted Amiga = Metal! Join Date: Jul 2009 Location: Stavanger / Norway Posts: 92	Ok, will do! Thanks a bunch for the quick and useful reply!

05 October 2009, 21:39	#8
Benighted Amiga = Metal! Join Date: Jul 2009 Location: Stavanger / Norway Posts: 92	Wow, It really took time before I got myself to try this. I've tried a couple of times, but It's black screen all the way. No red or green LED either. I had to adjust all the pins on one side to make them fit in the socket, and I found it a bit hard to get the wire to stay in. It's probably too thin as you say. During my first attempt I used too much solder which made it impossible to get the rom into the socket. I fixed that, but still no joy. I've put in the old 1.2 KS and I get the boot screen. Although the floppy drive behaves kinda weird. It seems random when it spins. I also can't get it to read any disks. Pheww...

05 October 2009, 22:22	#9
Shadowfire Registered User Join Date: Aug 2001 Location: Connecticut USA Posts: 617	Did you ground yourself before fiddling with the chip? That same page has a title called Static Precautions, if you're not careful you can destroy the IC's just by touching the pins. Can you snap a photo of what you've done so far, installed in the system?

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