Posts by hawkman

I brought out the oscilloscope and measured 5 and 12V rails. Startup is snappy at 19ms. Shutdown a bit longer at 69ms. Very stable DC (5.08/12.14) on both rails during normal operation with all cards installed. I'm not sure how to measure step response, but given the other measurements do you think I need to?

I double-checked the chip as well, taking the old one out and putting the new one in. Same result of a non-booting system. No effect on voltages or startup/shutdown. I put the old chip back in and it returned to working.

Any other measurements you'd like me to do?

It's not so much that the chip lost its contents, because I can't re-flash it. The fact that it causes the Zorro bus to crash strikes me as highly unusual. It's worth pointing out that I'm testing this without the power-hungry A2630 board installed. Swapping back the original chip returns the system to a working condition with no issues with or without all cards reinstalled.

I'll hook up the scope to check if there's anything funky going on but I did recap the PSU last year with high quality components. My instinct is that it's not the PSU as nothing else is showing any issues in the system but I'll double-check to be sure.

Hi, I received the updated flash ROM for the Buddha IDE card and I'm having some issues getting it to work. I replaced the original following the correct orientation of the notch. Upon power on, the IDE drives did not boot. Figuring that it needed to be flashed, I booted up a floppy with the buddhaflashtool on it, taking care to hold the right mouse button down to disable the write protection.

The tool loaded the flash file correctly with checksum f1eed6c4 and then I pressed uppercase Y to begin flashing. It reported the following:

Press Y to start, CTRL-C to abort

Flashing now ...

Verify failed - Possibly flash protection is on?

buddhaflashtool failed returncode 10

Any suggestions on how to resolve this?

*edit* One more thing, if I boot with both mouse buttons and look at expansion board diagnostic, no cards show up at all. I have a couple of other cards in the system. When I remove the buddha or put the original ROM back in, everything shows up properly.

Thanks.

I also replied to the original email.

Hi Jens, it’s 102375.

I'd like to add a note to this thread - the Buddha card must be in the furthest right slot (next to the processor expansion slot) for this to work. Otherwise the machine will lock up. I assume this is because the card has not been autoconfigured.

I've searched and I can't find much evidence that a MC68882RC25C or any 68882 with a C at the end exists. Is there something else I should be searching for? Perhaps a known-good mask code?

Regarding the LED, it's not flickering due to software on startup or when the audio filter is changing mode - it's flickering all the time. That's why I suspect the U303 74F08 has failed because that's what controls it. I initially suspected the Q302 transistor but changing that didn't fix it. It's a big job for a minor issue so I need to find the time to tackle it. I've attached a scope reading of the LED 5V line (flickery!) and of the 5V rail of the PSU (rock solid!)

Back to the issue at hand, I have removed the FPU and have been running the memory test all the way through (takes a long time with this much memory!) and so far, no crashes. The FPU indicates MC68882RC25A, 1C12R, QENW9212 on the copper part and MSIA GKNWQ-5 and D22873-101 on the ceramic part.

What does this indicate, that my FPU is bad? Or do I need to replace it with a specific mask like I did for the CPU?

I have had to order a number of parts to work on these issues and they all arrived today. Progress so far:

First thing I did was replace the 68030 CPU with a nice, used ceramic-packaged 01F91C which I bought from a reputable seller. This had an immediate effect of being able to boot the computer from the Buddha IDE / SD adaptor with the BigRAM board installed. I was also able to boot into AmigaTestKit v1.18 on an ADF image using my GoTek external drive. By the way, I'm now suspicious of the original chip in my A2630 - the FPU is ceramic, why would the CPU be plastic?

After changing the CPU, running the memory test got me optimistic but... after about a minute, it crashed with illegal instruction exception much like above. I rebooted a few times and tried different memory tests - including just the chip RAM - and eventually got an exception each time.

Next, I recapped the power supply. This wasn't too hard, the board is all through-hole and very easy to work on. Other than a sense of accomplishment of not breaking it, there was no improvement to the memory tests. Illegal instruction crashes continue.

I'll note that although I can boot into the Workbench, eventually corruption starts creeping in and strange things happen. I tried running Basilisk II with MacOS because that's an app that can allocate a fair amount of memory, however eventually everything crashes.

The blinking power light is still going on. I followed the schematics and changed a transistor that controls it with no change. I haven't done it yet, but next up is changing the 74F08 that is next up the chain. I don't think I should be concerned about this as it relates to the BigRAM as it's just the LED; the 5V rail is rock solid.

So that's where I am. I now have a ITX power supply and I'm waiting on an adaptor cable for the Amiga to try out a completely different power supply.

In the mean time, is there anything else that I should be testing or doing?

And is there a chance that the BigRAM might actually be faulty here? How would I know?

Further on the voltage situation, it might be localized. Putting a voltmeter on a drive power line shows a stable 5V. However, the power LED shows significant fluctuations and the mouse is no longer working. I guess I'm going to have to pull out the schematics and figure this one out. BigRAM project now on hold until I sort out this mess...

Two things:

1. I've been searching for a replacement 68030 mask code 01F91C on eBay and most seem to be fake. If anyone has a pointer to a real one, I'd appreciate it. Question for the group, I'm pretty sure it's OK to buy a faster part, say a 33 or 50 MHz part and use it at 25MHz but you never know with Commodore things, will there be a problem? Also I assume that plastic versus ceramic, it doesn't matter right?

2. Since I started testing the BigRAM, I suspect that I put a lot of stress on the PSU 5V rail. The power LED is flickering now, even with the BigRAM out. I put a voltmeter on it and it's fluctuating from 3.5 to 5V. I take it that this is a sign that the PSU is failing?

Thanks for the very kind offer. I don't see a way to DM using this BBS - if there's a way, please DM me, otherwise if you'd like to contact me via email, let's see if this is a viable approach.

OK, I pulled the 68882, reinstalled the BigRAM and ran Amiga Test Kit. The machine had been off overnight so it started up and ran fine, at least initially. It did the first pass of the RAM test but failed with the exception below. Soft rebooting caused the software failure so it's safe to say it's still unstable.

The 68030 appears to be 59C74N, if I'm reading this correctly. Is it worth hunting down a F91C 68030 to replace this? Or should my next step be the PSU review?

Sadly the 4 meg of ZIP ram is soldered. I think Commodore was running out of parts when they made my A2630 - instead of resistor packs, there are individual discrete resistors sticking up from the RP pins! No sockets for me.

I'll try pulling the FPU.

Can you explain what "mask set F91C of the 68030 CPU" means?

Finally, I'll take a look at the PSU. If there is an issue there, I'd like to resolve it in any case even if the FPU delete fixes things.

Thanks.

Hello, I have just attempted to install my new BigRAM A2630 on my unmodified, 25MHz A2630 with 4 MB RAM. I am having stability issues with the board installed. I get the following:

- First time boot after card being out of the system often boots fine to workbench but eventually locks up with power light flashing

- Subsequent power cycles either get into a boot loop of flashing screens, flashing power light, or solid power light and nothing at all

- Removing the BigRAM makes the machine boot perfectly fine again

- Leaving the BigRAM in the machine with power off for a 15 minutes or more allows it to boot again with the same issues above

My first guess was something to do with caps and indeed I have read in a previous thread that this is likely due to some PSU caps, specifically the 5V rail. Could someone please advise me exactly which caps I should look at replacing and a recommendation for modern parts to replace them with?

Many thanks.

Final update: all done. WB3.2 installed and working. Things I learned here:

1. As unlikely as it sounds, the Buddha firmware somehow got corrupted between when the board was manufactured and the DOM loaded, and when I plugged it into my A2000. I don't really understand how this can happen but re-flashing seems like it should be an early troubleshooting step not a late one.

2. It's a bit weird that the LED pins are the opposite of what the A2000 case LED is. I'm not sure if this is because other cases are wired differently but it's a small thing that should be more clearly pointed out, perhaps on the instruction sheet.

Otherwise, I'm delighted. This thing is seriously fast! From power on to workbench in seconds.

After re-flashing, I installed WB3.1. It appeared to install correctly. However after rebooting (and power cycling) I just get stuck on a grey screen. You can see the SD-IDE drive LED work briefly but then it hangs. I'm running KS 3.1.4 in this case.

Booting from floppy, I can see the DOM and the SD-IDE drive in HDToolbox. However the SD-IDE drive shows as "unknown".

* Update, I tried WB 1.3 and booted successfully from KS 1.3. I also tried WB 2.1/KS 2.0 and it worked.

* Update 2, I reinstalled 3.1 and now booting from KS 3.2 and KS 3.1.4 *almost* works, getting "Please insert a volume containing LIBS/icon.library in any drive"... progress. I also figured out how to wire the LED, it's the opposite of how the connector in the case is wired. Top pin black, middle pin red.

WAIT! I think I figured it out - I re-flashed the Buddha and now it's booting from the DOM. I'm just about to try to install...

I just rummaged around in my parts bin and found an old IDE drive. I connected it (jumpered as master on the drive) instead of the IDE SD, ran HDToolbox and same thing - not detected.

I believe that it should have detected the IDE SD adaptor, which is the only thing connected.