Page 1 of 2 12 LastLast
Results 1 to 10 of 14

Thread: Restoring CPU card A3640

  1. #1
    vibros's Avatar
    Join Date
    Sep 2009
    Country
    Italy
    Region:
    Emilia-Romagna
    Posts
    2,020
    Feedback
    106 (100%)

    Default Restoring CPU card A3640

    Hello,

    i have here an A3640, rev. 3.1; it is not mine, anyway, after a short test that has given green screen, i have tried to clean some pads and resistors from leakage of acid, without any result. After surfing the valuable site of the user from Sweden 'Chukky', i have watched for damaged vias, without any success!
    Anyway, the last night, maybe i was dreaming, maybe not, i have chose to desolder all the GALs and put a socket on everyone and, in the meantime, look for something strange under the surface. So, after desoldering of U400 and U401, and looked at the schematics, referring to the material on the Haynie archive, i have discovered this: some pads on this PLDs are not connected, despite the logic equations of the contents of this GALs considers some of this unconnected pads into the equations (so, in other words, they are considered sometimes positive and sometimes negative!). But a not connected pad (nor to GND, neither to VCC) is floating or? And this is not the best situations or? Today, with a fresh mind, i will give a new watch to all of this, but i am sure that what i have wrote here is true!

    Cheers
    Stefano

  2. #2
    vibros's Avatar
    Join Date
    Sep 2009
    Country
    Italy
    Region:
    Emilia-Romagna
    Posts
    2,020
    Feedback
    106 (100%)

    Default

    Hello,

    so, i was dreaming! Anyway it was not completely my fault, because the unconnected pins are reported on the schematics with their function's name: this function is used internally by the PLD and it, for my opinion, do not needs to stay on the schematics! This had confused me!
    So, all is ok! I have followed the good tips has reported by user chukky on his Internet site, about the A3640.

    The CPU card on my hands was a result of a patchwork: the true history of this card is unknow by me, anyway, the PLDs was detached and, later, resoldered; how programmed, was by me not know! The card looks a bit messy and not well managed.
    Happily, this card is now fully working. What i have done is explained here...
    First of all, the most important action is to look very close the board to discover issues like tracks interrupted by age, signs of leakage of acid (as result of, the pads look very dull, not more shiny and very hard to melt the tin!) and defective VIAs. This action does not need any instrument!
    This card was affected by leakage of acid, in some pads of resistors and smd capacitors; cleaned the pads, i have desoldered all the PLD, to look under the surface for some signs of defect, but there all was ok. So, soldered the sockets, i have read all the contents of the PLD and compared this results against what is reported being the original content, found on some archive here and there around the NET. Compared that, result was that U208 and U401 was with wrong fuse map, and i have reprogrammed this two parts with original content. After that, returned the card to the original state, with new capacitors right positioned and new sockets, equipped the Master with a passive heatsink, i have inserted this baby on my A3000D and...Bang! A Workbench powered by a 68040...sadly not fast ram on the cpu board!

    Here the pictures!

    Click image for larger version. 

Name:	DCP_8996.JPG 
Views:	35 
Size:	163.7 KB 
ID:	149035 Click image for larger version. 

Name:	DCP_8997.JPG 
Views:	26 
Size:	179.7 KB 
ID:	149036 Click image for larger version. 

Name:	DCP_9001.JPG 
Views:	22 
Size:	179.2 KB 
ID:	149037 Click image for larger version. 

Name:	DCP_9002.JPG 
Views:	22 
Size:	156.0 KB 
ID:	149038 Click image for larger version. 

Name:	DCP_9003.JPG 
Views:	20 
Size:	156.0 KB 
ID:	149039 Click image for larger version. 

Name:	DCP_9004.JPG 
Views:	20 
Size:	123.2 KB 
ID:	149040
    Click image for larger version. 

Name:	sysspeed_040_system.jpg 
Views:	27 
Size:	31.8 KB 
ID:	149041

    Now a question: there is a MOD to eliminate wait states; this MOD requires new code for some PLD, and this is not a problem because the sockets.
    The question is, if modifications on the motherboard (Amiga 3000) are required to do this MOD working!

    Thanks!

  3. #3
    Jack of Many Trades, Semi-Master of Some thebajaguy's Avatar
    Join Date
    May 2017
    Country
    United States
    Region:
    Rhode Island
    Posts
    368
    Feedback
    34 (100%)

    Default

    Here's some links to ponder:

    http://www.amibay.com/showthread.php...l=1#post266058

    http://eab.abime.net/showthread.php?t=63160

    I believe the -2 wait state part codes are in there, along with some POI2 motherboard part mods (A4000x, optional), and he hints at having a means to double-clock the A3640 with some additional modifications. YMMV applies.

    I haven't seen any need for A3000 modifications with the updated A3640 GALs, but there are notes from Dave Haynie regarding the SuperDMAC -02/RAMSEY-04 timing being marginal on a certain signal that the v3.1 A3640 fixes make a bit less critical. I don't know how all that applies to Speedgeek's logic rework, or if it interacts with it (or avoids altogether).

    On A3000's, it is suggested to get the replacement motherboard GALs (vs the original PALs) for heat reasons. I have a set for one of mine and there is no functional difference, but they do run cooler (than PALs).
    Last edited by thebajaguy; 6th August 2019 at 02:08.
    A500(2x)/A1000/A1200/A2000(4x)/A3000D(2x)/A4000D(under repair)/A4000T (all loaded....Toys...Toys...Toys...)
    Former GVP Tech Support 1989-93 - The beatings will continue until morale improves...

  4. #4
    vibros's Avatar
    Join Date
    Sep 2009
    Country
    Italy
    Region:
    Emilia-Romagna
    Posts
    2,020
    Feedback
    106 (100%)

    Default

    Hello,

    i have upgraded the A3640 and this are the some values compared to a basic A4000@030; sadly i have forgotten to do a module with the values reported by the A3640 in the original state. Compared the new one against the old values was better to show here, anyway...

    before the MOD

    Click image for larger version. 

Name:	sysspeed_040_wait.jpg 
Views:	35 
Size:	59.1 KB 
ID:	149089

    after the MOD

    Click image for larger version. 

Name:	sysspeed_040_nowait.jpg 
Views:	33 
Size:	58.4 KB 
ID:	149090

    I would consider your request to upgrade your A3640, even if not in working order!

    Cheers

  5. #5
    vibros's Avatar
    Join Date
    Sep 2009
    Country
    Italy
    Region:
    Emilia-Romagna
    Posts
    2,020
    Feedback
    106 (100%)

    Default

    Hello,

    now some pictures of the game DOOM on my Amiga, with this A3640. The conversion used is 'ADoom'. The setup of the machine is: Amiga 3000 with OCS, 16mb ram (no burst mode, with my ZIP2SIMM adapter), and this baby, rev. 3.2 and MOD with no wait-state.
    Now on Workbench...

    Click image for larger version. 

Name:	doom_1.jpg 
Views:	22 
Size:	35.4 KB 
ID:	149313Click image for larger version. 

Name:	doom_3.jpg 
Views:	26 
Size:	24.9 KB 
ID:	149315Click image for larger version. 

Name:	doom_2.jpg 
Views:	26 
Size:	23.3 KB 
ID:	149314

    ...and on custom screen (don't care about quality of the colors, because ExtraHalfBrite screens are managed not correctly on conversion on JPG pictures)

    Click image for larger version. 

Name:	doom_5.jpg 
Views:	25 
Size:	29.0 KB 
ID:	149316Click image for larger version. 

Name:	doom_6.jpg 
Views:	24 
Size:	26.8 KB 
ID:	149317Click image for larger version. 

Name:	doom_7.jpg 
Views:	22 
Size:	20.4 KB 
ID:	149318

    Into window on workbench (OCS 640x512 16 colors) it gives about 5 frames/sec; on a own screen (ExtraHalfBrite 320x200) the frames rate can be vary from 7 to 16; it is very playable and smoothly on all situations (by the way, i have launched this game just to test this A3640, then i have played more then one hour!).
    So now i wish just to add this: to load WAD files (Plutonia, in this case) takes minutes (more then ten) with the scsi disk on the on board scsi of A3000D (this disk is not old, old, old; because it is 2GB in size and SysInfo gives a transfer rate of about 2.3 Mb/sec) and, after that, during game play, every call to the Harddisk gives a break on the flow of the action, even with this A3640...now, with my IDE card and a 70GB disk (pictured on the thread of my IDE@ZII), the load takes few seconds (less then ten) and during action, the charge from the HardDisk is not noticeable! Believe in me!

    Cheers
    Last edited by vibros; 2nd January 2020 at 13:57. Reason: bad english language

  6. #6
    Jack of Many Trades, Semi-Master of Some thebajaguy's Avatar
    Join Date
    May 2017
    Country
    United States
    Region:
    Rhode Island
    Posts
    368
    Feedback
    34 (100%)

    Default

    The native SCSI interface, if Sync is not supported by the drive (or the Sync bit is not enabled in CMOS - Aminet has a tool to tinker with it) then it will top off at ~2.3MB/sec - that's the SCSI spec for Async.

    It could theoretically get close to 5MB/sec not including file fragmentation and seek/spindle access delay under optimal config with Synchronous enabled. Setting the bit has a pitfall that you must have proper/optimal termination of the bus, and if you ever change the drives on the bus, turn the bit off before you add/change anything, as it can be a pain to undo that bit if you get SCSI bus errors in less than ideal settings.
    A500(2x)/A1000/A1200/A2000(4x)/A3000D(2x)/A4000D(under repair)/A4000T (all loaded....Toys...Toys...Toys...)
    Former GVP Tech Support 1989-93 - The beatings will continue until morale improves...

  7. #7
    vibros's Avatar
    Join Date
    Sep 2009
    Country
    Italy
    Region:
    Emilia-Romagna
    Posts
    2,020
    Feedback
    106 (100%)

    Default

    Hello,

    i am now close to two minutes, on onboard scsi, to load the data from WAD file of the game DOOM...anyway against less then ten seconds...and this is not matter of 'buffers' or 'max transfer' for FileSystem!
    Maybe the partition on my IDE card is PFS2; this is the only big difference that could be lead to this very good value. I repeat, during game play, the load of the game in progrees is unnoticiable on my card, but it stop the game play igf the game is launched from the SCSI disk.

    Cheers
    Stefano
    Last edited by vibros; 1st October 2019 at 13:18.

  8. #8
    vibros's Avatar
    Join Date
    Sep 2009
    Country
    Italy
    Region:
    Emilia-Romagna
    Posts
    2,020
    Feedback
    106 (100%)

    Default

    Hello,

    the card is now sold!
    This week-end the system look like this

    Click image for larger version. 

Name:	DCP_9103.jpg 
Views:	8 
Size:	136.1 KB 
ID:	150310

    For the purpose this computer usually does, there is a lack of a fast-ram controller suited for this type of cpu (despite the MOD, the local ram is not well served by this card), and, secondarily, a gfx card (or an AGA machine).

    With this configuration and DPaint 4.5, sunday and yesterday i have drawn this thing...just to test the machine

    Click image for larger version. 

Name:	DCP_9100.jpg 
Views:	6 
Size:	127.6 KB 
ID:	150311

    With or without A3640, DPaint 4 is almost the same ...different is during 3d calculation or game play with 'doom'.

    Cheers

  9. #9
    vibros's Avatar
    Join Date
    Sep 2009
    Country
    Italy
    Region:
    Emilia-Romagna
    Posts
    2,020
    Feedback
    106 (100%)

    Default

    Hello,

    know someone of you if there is differences between the A3000D motherboard and the A4000D motherboard, by the point of view of this MOD on this cpu card?

    I have read that motherboards clocked twice need extra modifications about this mod, but i have no idea if this is the case about A3000D and A4000D motherboards.

    The new owner of this card reach just a dark grey screen on his A4000D (where an A3630 work correctly), and obviously, i have not taken in consideration troubles, just because, as you can see on this thread, all was fine pratically at first shoot, on my A3000D.

    Any help and advise is more then appreciated!

    Thanks in advance

  10. #10
    cugar124's Avatar
    Join Date
    Feb 2011
    Country
    England
    Region:
    Norfolk
    Age
    49
    Posts
    1,570
    Feedback
    54 (100%)

    Default

    On the 3000 there are jumpers just like the 4000 so if he is using an accelerator card he will need to check these

    Sent from my LM-G710 using Tapatalk
    ZX Spectrum Plus;Gaming Ryzen 7 PC; A4000 Cyberstorm MK2 128MB, Ariadne 2, DCE Cybervision 64/3D, Indi Mk2 CR Fast ATAPS4,Pie3

Page 1 of 2 12 LastLast

Similar Threads

  1. restoring a 2000
    By britlord in forum Photo Booth
    Replies: 12
    Last Post: 2nd August 2019, 12:49
  2. restoring a3000
    By ozkano in forum Photo Booth
    Replies: 0
    Last Post: 26th October 2014, 11:25
  3. Replies: 14
    Last Post: 25th March 2013, 19:36
  4. Help restoring an Emac?
    By scrappysphinx in forum AmiOracle
    Replies: 6
    Last Post: 5th July 2011, 10:35

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •