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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: CaelThunderwing on November 16, 2016, 08:19:58 PM

Title: A500 Rev5 3.1 KS upgrade Questions
Post by: CaelThunderwing on November 16, 2016, 08:19:58 PM
is there a way w/o sodering? im reeeealy horrible at such and dont want to Burn off a 300$ investment,  is it possible to get like a Rom socket adapter thats prejumped/wired to fit in over it to go w/ a KS 3.1 Rom?  or should i keep mine @ 1.2?

Edit not sure title will update i typo'd my Board revision, its Rev5
Title: Re: A500 Rev5 3.1 KS upgrade Questions
Post by: spaceman88 on November 16, 2016, 08:37:27 PM
Quote from: CaelThunderwing;816508
is there a way w/o sodering? im reeeealy horrible at such and dont want to Burn off a 300$ investment,  is it possible to get like a Rom socket adapter thats prejumped/wired to fit in over it to go w/ a KS 3.1 Rom?  or should i keep mine @ 1.2?

Edit not sure title will update i typo'd my Board revision, its Rev5


I just went through this a month or so ago. Some people have modified a socket to sit between the ROM and the motherboard socket, but when I tried I found it didn't make a good connection, so I just soldered one jumper on the bottom of the motherboard and another on the chip, worked great.
Title: Re: A500 Rev5 3.1 KS upgrade Questions
Post by: CaelThunderwing on November 16, 2016, 08:39:46 PM
again though im trying to aim w/o soder i just reeeealy do not want to as i said Burnt my investment. would say fitting a Jumper wire Between the pins in the Socket do?
Title: Re: A500 Rev5 3.1 KS upgrade Questions
Post by: spaceman88 on November 16, 2016, 10:11:59 PM
Might be hard to get a good connection without solder. The advantage of putting one of the jumpers on the bottom of the board is it's very hard to do damage unless your really bad at soldering, of course you still have to solder to the bent up pin 31. If your really nervous about it you can probably find a TV/computer repair shop that wouldn't charge much for a couple of jumpers.
Title: Re: A500 Rev5 3.1 KS upgrade Questions
Post by: psxphill on November 16, 2016, 10:45:07 PM
Quote from: CaelThunderwing;816508
is it possible to get like a Rom socket adapter thats prejumped/wired to fit in over it to go w/ a KS 3.1 Rom?  or should i keep mine @ 1.2?

An original 3.1 ROM from the 1990's will work with just a jumper between pin 1 & 31. This would be my recommendation, but cost may be an issue.

eproms need more work.

1. Bend up pin 31, solder it to pin 21 to keep it in word mode.

then to get A17 on pin 1 either

2a. build a tower with two rows of pin headers and solder a wire from pin 1 of the rom to the empty hole of pin 31. This has the disadvantage of making the rom higher, which can cause a problem for some expansions.

or

2b. solder a wire from pin1 to pin 46 of the 68000.

I wouldn't hack a revision 5 motherboard. I think the ACA500 would allow you to run kickstart 3.1 without even opening the case.
Title: Re: A500 Rev5 3.1 KS upgrade Questions
Post by: Oldsmobile_Mike on November 16, 2016, 11:15:37 PM
Not that it's terribly helpful but a quick search on ebay shows a bunch of Rev. 6 A500 motherboards starting in the $60-$70 USD range.  With the newer board it's just "pop right in", you don't have to do any soldering or modifications.

http://amiga.resource.cx/mod/a500.html

You also get to take advantage of the higher density ram chips & newer-model Agnus.  :)
Title: Re: A500 Rev5 3.1 KS upgrade Questions
Post by: psxphill on November 16, 2016, 11:53:21 PM
Quote from: Oldsmobile_Mike;816519
Not that it's terribly helpful but a quick search on ebay shows a bunch of Rev. 6 A500 motherboards starting in the $60-$70 USD range.  With the newer board it's just "pop right in", you don't have to do any soldering or modifications.

http://amiga.resource.cx/mod/a500.html

You also get to take advantage of the higher density ram chips & newer-model Agnus.  :)

If you want > kickstart 1.3 and a newer agnus then I'd have thought an a500+ would be a better starting point. Back in the day I had my rev 5 tricked out with 2mb agnus plus an extra 1.5mb in the trapdoor and a home made gary tower to make it all work together with kickstart 1.3 and 3.1. But today I would just leave everything stock and just use trapdoor and maybe an expansion port accelerator + hard drive + ram.