Welcome, Guest. Please login or register.
Amiga Kit Amiga Store Iridium Banner AMIStore App Store A1200/A600 4xIDE Interface

AuthorTopic: Will a 2.04 Rom work in a rev 5 A500?  (Read 917 times)

0 Members and 1 Guest are viewing this topic.

Offline zx6r6

Will a 2.04 Rom work in a rev 5 A500?
« on: July 06, 2005, 11:11:10 PM »
The subject says it all! Its a rev 5 500 with ocs and half meg agnus. With a (working) 2.04 rom I get a red screen at startup. If I change denise,agnus etc to the ecs versions will it work then?

cheers

p.s anyone want to sell me their Amiga One!?
 

Offline rhino

Re: Will a 2.04 Rom work in a rev 5 A500?
« Reply #1 on: July 06, 2005, 11:37:10 PM »
Quote

Its a rev 5 500 with ocs and half meg agnus. With a (working) 2.04 rom I get a red screen at startup. If I change denise,agnus etc to the ecs versions will it work then?


IIRC older A500 motherboards needed a jumper link between two pins on the 2.04 ROM to work. The original upgrades were supplied with this jumper in place and it was to be snipped when installed in newer boards. If your ROM doesn't have a jumper you'll probably need to add one. The best reference I could find with a quick Google was this one:

http://www.titan.co.nz/amigaak/AA060127.htm

HTH

Robert
Editor of Total Amiga Magazine
Author of AmiPodder, podcast receiver for the Amiga
 

Offline zx6r6

Re: Will a 2.04 Rom work in a rev 5 A500?
« Reply #2 on: July 06, 2005, 11:50:38 PM »
Guess I'll have to change my search engine, I couldn't find any info! I'll give it a go tomorrow.
cheers for your help!
 

Offline Argus

Re: Will a 2.04 Rom work in a rev 5 A500?
« Reply #3 on: July 07, 2005, 12:39:05 AM »
iirc you need to connect a small wire between pins 1 and 21 on the rom chip.
posted on A2500+ C=2620 14MHz/8MbFast/1MbChip
dialed in @34K
Just livin\\\' the dream...
 

Offline bloodmoney

Re: Will a 2.04 Rom work in a rev 5 A500?
« Reply #4 on: July 07, 2005, 04:19:47 AM »
That is incorrect I believe. Connect 1 to 31 should be correct. 1 to 21 is for 3.1 rom
kickstart A metal bread tie and a solder iron will do.

Offline zipper

Re: Will a 2.04 Rom work in a rev 5 A500?
« Reply #5 on: July 07, 2005, 05:35:39 PM »
2.x and 3.1 behave the same, needing the mod.
 

Offline Generale

Re: Will a 2.04 Rom work in a rev 5 A500?
« Reply #6 on: July 09, 2005, 09:56:50 AM »
Ohhh...I see. So it needs the jumper wire for newer KS on the older boards.

Stupid question. I had a KS rom switcher kindly donated to me with an unknown KS on it. It didn't work with either of my r5 a500s. One of them has ks1.2 and the other has ks1.3. Neither has the jumper wire.

Would the wire do the trick? And is it 1->21 or 1->31?
A500 (salvo): 1Mb RAM (512k chip, 512k SlowFast)
1x880k Floppy Disk, 1xIBM 540Mb 3.5\\"HDD KS1.3, WB1.3
1084S monitor. AT Keyboard!
A500 (Whitey): 512k RAM, 1x880k Floppy Disk, KS1.2, WB1.3
 

Offline zipper

Re: Will a 2.04 Rom work in a rev 5 A500?
« Reply #7 on: July 09, 2005, 10:10:45 AM »
(reading the official Rom update instructions:)

For ..and rev.5 boards, the ROM socket must have pin 1 connected to pin 31 and the ROM IC must have connected pin 21 to bent-up pin 31

(VillageTronic "English")
 

Offline Generale

Re: Will a 2.04 Rom work in a rev 5 A500?
« Reply #8 on: July 10, 2005, 04:45:04 PM »
is there any real reason to do the pin 1->31 bridge on the socket? why not do both 1->31 & 31->21 on the ROM?
A500 (salvo): 1Mb RAM (512k chip, 512k SlowFast)
1x880k Floppy Disk, 1xIBM 540Mb 3.5\\"HDD KS1.3, WB1.3
1084S monitor. AT Keyboard!
A500 (Whitey): 512k RAM, 1x880k Floppy Disk, KS1.2, WB1.3
 

Offline melange

Re: Will a 2.04 Rom work in a rev 5 A500?
« Reply #9 on: July 12, 2005, 10:27:21 AM »
I have done the mod for the A500, it was simply pin 1 -> 31 on the rom.  I didn't have to bend any pins.  Just soldered a wire from pin 1 -> 31.  At least that's how I remember it.  Was a long time ago.

2 x A1200 Blizzard IV 030@50Mhz
1 x A3000D 030@25Mhz
1 x A2000 030@25Mhz
1 x A2000, 2 x A600
2 x A500