Amiga a2091 not working with ram installed... :(

[waltermixxx]

hi there I recently aquired an Amiga a2091 scsi board with no ram.
so I took the 4c4256-8 chips from an amiga 500 baseboard 2meg trapdoor upgrade ( working ) and put them into the a2091.

the board does not want to work, i get a red screen showing two boards, one working the other one not working... and then click continue, and I can boot into 3.1....

u14 and 15 get hot for some reason... this ram worked fine, pulled from a working expansion...

http://www.flickr.com/photos/66577016@N00/9513357632/

this is the error message...

any hints?

cheers

[emufan]

of no real help, but with the boards.library you can at least identify the numbers:

showboards MID=514 ALLKNOWN

Manufacturer 514: Commodore (West Chester) 
  1: A 2090/2090a SCSI                                   ID: 1   
  2: A 590/2091 SCSI                                     ID: 2   
  3: A 590/2091 SCSI                                     ID: 3   
  4: A 2090B 2090 Autoboot Card                          ID: 4   
  5: A 2060 Arcnet                                       ID: 9   
  6: A 2052/2058 | 590/2091 RAM                          ID: 10  
  7: A 560 Arcnet                                        ID: 32  
  8: A 2232 Multi Serial Prototype                       ID: 69  
  9: A 2232 Multi Serial                                 ID: 70  
 10: A 2620 020 Turbo                                    ID: 80  
 11: A 2630 030 Turbo                                    ID: 81  
 12: A 4091 SCSI                                         ID: 84  
 13: A 2065 Ethernet                                     ID: 90  
 14: Romulator Card                                      ID: 96  
 15: A 3000 Test fixture                                 ID: 97  
 16: A 2386SX BridgeBoard                                ID: 103 
 17: CD32 SCSI Controller                                ID: 106 
 18: A 2065 Ethernet                                     ID: 112 

18 boards known of this manufacturer.

so i would say a ram problem "ID:10"

Edit: it is this a2091 card ?
it has a jumper to change the amount of added memory, maybe try removing some chips, and try with less memory.

[r.cade]

Bad RAM. If they get unusually hot, they are shorted internally. Likely they were installed backwards or a pin off and are now damaged, or were that way before you installed them.

[waltermixxx]

That is a help, it confirms it's the ram and provides lots of good information
I tried with 1meg and two meg and made sure i had the ram jumper set accordingly
same error... could the the little ram controller chip, it's one of those programmable GAL chips i think...

ok thank you, any other suggestions?

[waltermixxx]

Ram tested fine in Baseboard Ram expansion for Amiga 500. Pulled from one, and then put back in after to make sure they were ok... and the ram lives...

Originally Posted by r.cade

Bad RAM. If they get unusually hot, they are shorted internally. Likely they were installed backwards or a pin off and are now damaged, or were that way before you installed them.

[IceBladew123]

Got a similar problem with my A590. It works fine without any ram installed, but when I turn the RAM on I got a yellow screen and the RAM controller U5 start getting hot.

I wanna try to replace it using a gal16v8d-25lp as explained here:
http://www.amigawiki.org/doku.php?id...s:pld_download

Hope this helps.

Denis

[waltermixxx]

that is very helpful, gives me an excuse to go out and buy a programmer for GALs, and PALs.

cheers

[SpeedGeek]

The A2091 RAM controller continuously refreshes all RAM. The refresh cycles are interleaved with memory cycles. This causes the RAM chips to get very warm but if 2 chips are getting much hotter than the others then there is problem with the RAM chips, RAM controller or the connections between them.

[waltermixxx]

Hi SpeedGeek, I think i am going to try the 14mhz mod...
I put version 7.0 roms in my card last night, and I am trying to format the one of the 4 surplus drives I purchased...

seems to take forever to format (using the o.s.) for some reason the format program on the 1.30 2091 install disk does not want to work for some reason (drive cannot be found, even though it's on the desktop as DH0.xxxxxx )...

besides version 7.0 being the best for this mod, are there any other requirements for the mod? any patched version of the roms?

cheers and thanks for your comments here...

i was hoping to boot from a 3.1 disk, (i have 3.1 roms) how do I add the drive to my 3.1 disk? ( i have to edit the user startup file in sys ) just not sure what the syntax is ...

cheers

[waltermixxx]

Just a big big thanks to SpeedGeek for his work on the 14hmz mod and patch to U12. I got a hard drive working ( 1 gig currently, but got it working with a 4 gig as well ) the memory for what ever reason, seems to be working now... ( I tried different ram and it seemed to like it better...)

so I have me an Amiga 2000 with 1meg of fastram and 1meg of chip ram so I am very happy...

Thanks again

[SpeedGeek]

Congratulations waltermixxx!

If you've already enabled Sync mode (assuming your HD supports it) the only thing left to do is install A2091ToFastV2.0 but you'll need an accelerator to get any real speedup from it. (Links are already posted here on EAB to the Amibay threads and Amibay links to EAB as well).

Formatting an HD is a very disk intensive process and is largely dependent on the size and speed of the HD (or partition) so bear that in mind since these mods were designed primarily to speed up SCSI transfer rates...