Speed up the A3640!

[8 Bit Dreams]

I'm building it for another user who is unable to solder it, no idea how he got one

[jbenam]

Originally Posted by 8 Bit Dreams

I'm building it for another user who is unable to solder it, no idea how he got one

If you can, please try asking the user how he got one. I am very interested, thanks

[trixster]

Originally Posted by 8 Bit Dreams

Have built this board, but RAM shows up only one or two times from ten ??
I've used Alliance and Micron type memory, swapped CPLD out but no luck

We have exactly the same problem, with two boards which have been soldered up and tested on an A3640 and A3660.

Ram not showing up except about one reboot in 10. Every IC checked and/or swapped with known working ones.

Very frustrating.

[jbenam]

Well... Then it looks like it was a blessing in disguise that lukzer never replied to my PMs

Looks like a timing issue?

[GadgetUK]

Same problem here with two boards I built. I've tried the updated firmware today - this one wont boot it seems. No power light flashes or anything to provide a clue. I did make sure SJ4 and SJ3 were shorted to ground (as per this specific firmware - dont set those if you aren't using the firmware I am).

The RAM was exactly from the BOM (provided by Digikey). The CPLDs, I've swapped out too with known good ones from Farnell - same behaviour.

The behaviour with the release firmware was occasional yellow screen, quick power off and on and it would boot fine, but with no additional RAM.
DiagROM would always show no additional RAM on first boot, after 1st boot different amounts of RAM would be reported - often around 33MB (taking into account also the 16MB of SIMMS on the mobo).
1 out of maybe 20 or so cycles I did see the full 64MB + 16MB SIMMs appear in DiagROM, and the memory test passed at that point.

The FB100 wire is needed for the A3640 as well as A3660 - I wasn't aware of that initially. On the A3640, FB100 is underneath the PCB and I believe the pads are in different order to the A3660. I assume you are all using that wire, and if fitted to A3640, I assume solder to the LEFT pad, rather than the RIGHT pad when using A3660 PCB?

[8 Bit Dreams]

thanks for Your input Gadget, will move that wire to the left side and check if things getting better. As for now - it seems to me this is 100% timing issue, it's hard to make it work stable because GALs have different Timings, some are 10 and some are 15ns... some Users are on original JEDs for GALs, and some have SpeedGeek Jed's with less Waitstates, this is a nightmare to make it work, so at least two firmwares should be done. Another option might be to change Autoconfig priority, and make this card last to config...

[8 Bit Dreams]

Swapping patchwire to other side prevents Amiga to boot, so right pad should be correct,
I'm getting better results with WB3.9 while KS3.1 is installed, seems soft reboot makes sense

[GadgetUK]

Originally Posted by 8 Bit Dreams

Swapping patchwire to other side prevents Amiga to boot, so right pad should be correct,
I'm getting better results with WB3.9 while KS3.1 is installed, seems soft reboot makes sense

Not according to the creator?!?

The A3660 (Chuckys PCB) - pad is right side
The A3640 PCB (Commodore) - pad is left side


My understanding is it shouldnt go to the CPU pin, it should go to the side that goes off to the GALs.

Quote "Yes. FB100 pin should go towards GAL / PAL, not CPU."

[GadgetUK]

Has anyone made progress with this yet? Just doesn't work here - either on A3660 PCB or A3640 PCB.

[GadgetUK]

It might help to understand how the Damien got his originals working - ie. A3640 (what rev?) or A3660 PCB, any GAL updates? Tested on A4000 or A3000, which rev motherboard? What versions of Kickstart have been tested?

[Chucky]

A3000 would crash.. MAYBE without anything on the SCSI bus.. as.. DMA

[lukzer]

i know about problems with my card and i am trying to fix it.
For this reason, the cards are unavailable until the problem is resolved.

[GadgetUK]

Originally Posted by lukzer

i know about problems with my card and i am trying to fix it.
For this reason, the cards are unavailable until the problem is resolved.

No worries =D Thanks for letting us know!

[8 Bit Dreams]

I'd like to help debugging it, have original A3640 and A3660 rev1.1 cards here,
Just need to know what combination of JEDs to use before I start to desolder GALs.. Should I take SpeedGeek or original 3.2 JEDs to get better results???

[GadgetUK]

Any news on this?

[GadgetUK]

Bump - no more news???

[GadgetUK]

No more news on this? Have to be honest - feeling a bit annoyed with this! Out of interest, has anyone out of the first group got theirs working at all? We should start comparing specs of boards to see if we can work out where the issue is. Lukzer did ask me if I could scope a few signals, I will try and do that when I am able to get the 4000 PCB onto the bench.

[Chucky]

My guess of the silence is issues that WILL pop up due to no DMA

[patrik]

Also nowadays there are more options - there is at least one newly produced A3000/A4000 accelerator that you can buy today, which out of the box is fast and has onboard ram.

[GadgetUK]

Originally Posted by lukzer

i know about problems with my card and i am trying to fix it.
For this reason, the cards are unavailable until the problem is resolved.

Is there any update on this, or did this project just die?