Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Cldrnbrn on October 17, 2008, 01:25:34 AM
-
Digging though my Amigas here and trying to decide which one to max out. I've got a A2000, A2000HD, A2500. My question is how do I tell which mb revisions I have? One is labeled 6.2 but the others I have no idea. I think the A2500 has later stuff in it just due to several chips having higher numbers but unsure.
Along with this is there a site somewhere explaining the differences in the revisions of chips like Gary, Buster, Angus, Paula, ext... There are different versions in these and I would like to keep the best ones if possible in the best looking, etc machine. What are the highest versions that this computer will support? If I don't have them where can I find get them?
-
http://www.bboah.com/cgi-bin/showcat_en.cgi?CATID=1
-
The Rev 4 or 6 should be silkscreened on the lower left hand corner of the motherboard. Further factory enhancements were usually indicated by the addition of a tiny white sticker somewhere near the top of the Zorro slots (but may have since fallen off). Rev 4 boards have iirc 32 chip ram chips while Rev 6 have only 8. You can usually tell an upgraded Rev. 4.x board up to Rev.4.5 iirc if you see a resistor soldered onto the top of the small chip located between the cpu slot and the first Zorro 2 slot (U605?). The uprated boards should also have a different Gary chip (MOS), a modification near the mouse connector and a resistor added near the power supply connector. There's a good description on how to upgrade a Rev. 4 boards to 4.5 on Usenet.
-
I still have the CBM Amiga Revision Service notes.
If anyone wants i'll post the Rev. info tomorrow. In my opinion the worst A2000 Rev. was 4.2 where the ground plane could actually burn and lift off the board around the Paula and Denise chips.
Shaf
Former CBM Service tech.
-
I've already been to that site and all it does it give me a bunch of pics of what they could be, didn't help much. Problem I have is they are all at least Ver 6 since that is what is silkscreened into the board. Only one of them has the sticker stating 6.2.
-
Here is your answer. Reading carefully, note the ROM tower or lack of it, and the upgrades in chips. That explains the differences in the A2000 rev 6 board visually. There are added components in these rev's, but the quick anser is TOWER and/or chips.
MOTHERBOARD REVISIONS:
Pre 4.x were German motherboards. Not recommended for use at all.
4.2
4.3
4.4
4.5 Last in the 4.x series
6.0 Has ROM tower for Kickstart, buggy with some expansion cards.
6.2 Removed ROM tower for Kickstart that was on 6.0 board.
6.3 Now has KS2.04 ROM, 8375 Agnus and 8373 SuperDenise as standard
6.5 Have not seen one
This came from a David Haynie file that I kept.
-
The 6.2 is a damn good board. You probably wont find a better one to build, as 6.3/6.5 is pretty rare.
When trying to "max out" an A2000, remember this: The expansion bus is only 16bit..
So get everything you can on the accelerator.. Anything on the accelerator is hooked to the CPU via a 32bit bus and will perform a whole lot better than anything you stick in a zorro II expansion slot. Stuff like sound cards, serial ports, etc. are fine as 16bit cards.. Stuff like memory, hardisc controllers, graphics cards, etc. are best on a 32-bit bus. So the key to having an A2000 with decent performance is DON'T SKIMP ON THE ACCELERATOR. You should definitely try to get one with a decent amount of on-board 32-bit fastram and on-board scsi at the very least.
The abslolute baddest accelerator Ive ever seen for the A2000 was the DKB Wildfire 060/50mhz. It was roughly comparable the Cyberstorm/Blizzard 060 cards available for the 32-bit AMIGAs.
Wildfires are probably pretty damn rare nowadayze.. but if you really want to make your A2000 compete with the A3000/A4000/A1200/T systems, it's the best option. And, I believe it even had on-board ethernet.
-
The 6.2 is a damn good board. You probably wont find a better one to build, as 6.3/6.5 is pretty rare.
How about 6.4?
I was digging around, looking at photos of my Amiga 2000 motherboard, and I believe it is a Rev 6.4. It has an 8375 / 318069-17 Agnus which apparently (https://en.wikipedia.org/wiki/MOS_Technology_Agnus) is an A2000 Rev 6.4 part able to address 1MB CHIP RAM, and also an 8373 Super Denise (ECS) in regards to which, BBoAH notes:
Rev 6.4 ( ECS Denise introduced, last 6.x revision at A2000 End Of Sale* )
* An extremely late production (more likely a replacement A2000 issued under warranty), with Rev 6.4 clearly labeled, but the post-8372A production spare part (NTSC) 8375 Agnus w/318069-16 (and required mod), which came with an A2000C sticker on the rear of the case.
I purchased this system in Late 2000 from a forum post where someone had 30 or so NIB A2000 units with KS2.04 and was selling them at a reasonable price. There were three remaining and I ordered one. There was a delay shipping due to warehouse confusion and so the guy threw in an ASDG Dual Serial board at the end of it all. The system was in mint condition and appeared to have not been used before - zero dust. I have been using this system since. I currently have an A2620 (Commodore 68020 accelerator) installed, but I am trying to find a different option, as I need a hardware disable switch for the accelerator.
Pics of the system internals (https://www.flickr.com/photos/blakespot/albums/72157604299491786/)
bp