A4000 + A3660 Fast Ram Issue

[johntayloruk]

Hi Everyone, new poster to the EAB but been reading some of the things on here for a while. Hoping that someone out there can help me from pulling out what remains of my hair

Sorry for the long Post!

Some brief background on my setup:

- A4000/030 CPU
- 2MB Chip Ram, 16MB Fast Ram
- Picasso IV
- BigRamPlus 256MB
- X-Surf-100 for Ethernet
- Workbench 3.1.4 and have Genuine 3.1.4 ROMS
- I recapped the motherboard and replaced the RTC/cleaned up the whole area from a battery leak. At the time I checked all the traces and found everything was working fine and passed all checks in SysTest. I've taken pictures of the area.

All works absolutely fine and all memory (including BigRamPlus board) detected. I've been fancying a speed boost so I purchased an A3660 Rev 1.1 with Rev5 68060 CPU.

To setup the A3660 I copied over the 68060.library file to by Workbench 3.1.4 LIBS: folder. I then replaced my 3.1.4 ROMS with the patched ones the A3660 came with. Changed J100 & J104 to External, slotted in the A3660 and....flashing yellow screen. I tried removing things and found that if I removed all the cards and only left in 2MB Chip Ram +16MB Fast Ram, the screen would flash yellow a few time, but then booted into Workbench. However...….only 500k of Chip ram was available and 0 Other Ram. So the Fast Ram was not being detected at all. ARGH!

Troubleshooting things I've tried & Some interesting (and confusing) findings:

- Removing and re-seating everything
- The first thing I tried was removing and re-seating the A3660 - No Change
- I tried re-inserting the BigRamPlus card only - Got a Board Error message (v. odd as the BigRamPlus card is brand new)
- I read on forums that the 3.1.4 ROMS would work with the A3660, so I removed the patched roms and replaced them with my original 3.1.4 ROMS - same thing happened
- I inserted my DiagRom BIOS chips and it hang. Seems like it was showing a problem with the Memory being detected. I tried this with all my banks of 4MB SIMM's, and had the same issue.
- I removed all FastRam and it booted to Workbench with no Yellow screen
- Concerned at this I swapped out the A3660 for the original CPU and everything ran and tested fine.
- I then put everything back to its original state (CPU, Jumpers, Memory, Cards etc) and everything worked absolutely fine and workbench detected all my Ram.
- I also checked the Diag. info for the cards and all were shown as Working.


So, I need some help here.

- Has anyone had this kind of issue or could advise that I'm missing something obvious?

- Could the Yellow screen mean anything else?

I'm confused why everything works find with the original 68030 CPU, but when I put in the A3660 card everything shows as having an issue. It's driving me crazy so if anyone can help it would be very much appreciated!!

[Kin Hell]

Exactly which 060 Library did you copy over?

See here for different versions & the Latest: http://phase5.a1k.org/index.html - Not sure if A3660's have their own Version?

Different versions of 060 Library can have different effects on different hardware combinations & that's before you even include the recent A3660 card.

Also, you state everything was okay for putting the original A3640 back in. Did you also replace the 040 Libs because they work differently to the 060 Libs.

[trixster]

You say the machine is originally an A4000/030 but later say you put back in the A3640 - is your machine definitely an 030 (with A3630) or is it an 040 with A3640?

Check the INT/EXT jumpers - these need to be set to EXT for an A3640 or A3660. I think they are set to INT if your card is a A3630, so this might be your problem

[Kin Hell]

That's a good point Trixster.

Set to INT for A3630 & EXT for A3640/60

If you did have an 040 Card in place beforehand, then the Jumpers should already be set to EXT.

[johntayloruk]

Thanks for the responses:
I've corrected the mistake - My original CPU was a 68030, not 68040.

Kin Hell - I copied over the 68060.library file to LIBS: When I switched back I re-instated my 68030.library

Trixter - Jumpers were both set to EXT when trying to use the 68060 and INT when putting back the 68030 CPU

[Kin Hell]

Originally Posted by johntayloruk

Thanks for the responses:
I've corrected the mistake - My original CPU was a 68030, not 68040.

Kin Hell - I copied over the 68060.library file to LIBS: When I switched back I re-instated my 68030.library

Trixter - Jumpers were both set to EXT when trying to use the 68060 and INT when putting back the 68030 CPU

Er.... afaik, there are no specific CPU Libs required for 68000, 68010, 68020 or 68030.

Not sure if the A3640 needs just one of the Mobo Jumpers setting to EXT if an FPU is fitted to the A3640. - Can anyone clarify this please?

[johntayloruk]

Hi, the 68030.library file was required to remove the prompt when Workbench 3.1.4 boots.
I used the ones from MMULibs for this, which works fine.
I'll check just putting one of the jumpers to EXT...bear with...

[hooverphonique]

Both jumpers need to be EXT for A3640. They have nothing to do with FPU, but set whether the motherboard is clocked from its own oscillator or the cpu board in the cpu slot.

[johntayloruk]

To confirm, tried the suggestion and still not working. Agree from docs I've read that J100 and J104 should be set to EXT.

[johntayloruk]

So something strange and more fun and games....I started to check the traces around j100/J104 and all seemed ok, apart from on the bottom of the PCB J100 Pin 2 was connected to U102 Pin 4(T2) on the EP8700. I've checked on Amiga PCB Explorer and the A4000 Rev. B schematics and I cant see this in place. I've attached a picture showing the wire bridge.

I tried removing this, setting J100 and J104 to External and then booting with the A3660. This time I got a completely black screen.

I then put the bridge back to check against original setup (cautious me) and now I'm getting a bloody Blue screen when I boot with the original A3630 CPU. I'm giving up for today, but if anyone has any ideas I'm open to listening.

Some additional info:

U102 is an EP8700
U103 is a 74FCT244TP

[hooverphonique]

The mobo EP8700 does nothing when the jumpers are set to EXT, though. @25MHz, the period is 40ns, so to get a 90 degree skew, CLK90 should go to the 10ns (40ns/(360/90)) tap, but maybe somebody overclocked the mobo at some point?

[Kin Hell]

Originally Posted by Kin Hell

Er.... afaik, there are no specific CPU Libs required for 68000, 68010, 68020 or 68030.

Not sure if the A3640 needs just one of the Mobo Jumpers setting to EXT if an FPU is fitted to the A3640. - Can anyone clarify this please?

Originally Posted by hooverphonique

Both jumpers need to be EXT for A3640. They have nothing to do with FPU, but set whether the motherboard is clocked from its own oscillator or the cpu board in the cpu slot.

Darn it.... I meant to say A3630. Sorry guys.....

Originally Posted by johntayloruk

<snip>
To setup the A3660 I copied over the 68060.library file to by Workbench 3.1.4 LIBS: folder. I then replaced my 3.1.4 ROMS with the patched ones the A3660 came with. Changed J100 & J104 to External, slotted in the A3660 and....flashing yellow screen. I tried removing things and found that if I removed all the cards and only left in 2MB Chip Ram +16MB Fast Ram, the screen would flash yellow a few time, but then booted into Workbench. However...….only 500k of Chip ram was available and 0 Other Ram. So the Fast Ram was not being detected at all. ARGH!

<snip>

Surmising from what we already know, A3640 has to have J100 & J104 set to Ext for it's clock speed. This card has it's own divide by 2 counter so the 50Mhz X-Tal once divided by 2 results in 040 @ 25Mhz.....

However, J100 is CLK90 Clock Source and should be set on Pins 1&2 (INT) when using an A3630 card. These cards have their own Jumper settings for FPU package style. J104 should also be set to INT when using an A3630 card.

A4KD Mob Jumpers here: http://www.zimmers.net/cbmpics/cbm/a...00jumpers.html

A yellow flashing screen usually means either CPU isn't seated correctly or Memory issues. Remove all Fast Ram modules first & retry A3660 with specific patched ROMS. If it works, then the CPU card is fully seated.

If it isn't working, please be aware of this:
The Mobo flexes between chassis stand off's so pull the Front Drive bay Sub frame out of the main chassis so you can check if the CPU Edge connector is seated fully. If you dont mind a bit of pain, Jam finger tips between mobo & chassis while pushing down on CPU card or jam one of those Wedge shaped Pencil Erasers between mobo & chassis & then press the A3660 home.

Really not sure about the Wire on the back-side of the Mobo. I don't recall ever seeing one on any one of the many A4KD's I have owned.

[johntayloruk]

Originally Posted by Kin Hell

Darn it.... I meant to say A3630. Sorry guys.....



Surmising from what we already know, A3640 has to have J100 & J104 set to Ext for it's clock speed. This card has it's own divide by 2 counter so the 50Mhz X-Tal once divided by 2 results in 040 @ 25Mhz.....

However, J100 is CLK90 Clock Source and should be set on Pins 1&2 (INT) when using an A3630 card. These cards have their own Jumper settings for FPU package style. J104 should also be set to INT when using an A3630 card.

A4KD Mob Jumpers here: http://www.zimmers.net/cbmpics/cbm/a...00jumpers.html

A yellow flashing screen usually means either CPU isn't seated correctly or Memory issues. Remove all Fast Ram modules first & retry A3660 with specific patched ROMS. If it works, then the CPU card is fully seated.

If it isn't working, please be aware of this:
The Mobo flexes between chassis stand off's so pull the Front Drive bay Sub frame out of the main chassis so you can check if the CPU Edge connector is seated fully. If you dont mind a bit of pain, Jam finger tips between mobo & chassis while pushing down on CPU card or jam one of those Wedge shaped Pencil Erasers between mobo & chassis & then press the A3660 home.

Really not sure about the Wire on the back-side of the Mobo. I don't recall ever seeing one on any one of the many A4KD's I have owned.

Thanks for the tip regarding a Pencil Eraser! Saved my fingers.

So I removed the wire that's bridging the two pins, set the jumpers to EXT and then firmly seated the A3660 CPU. The power light blinks and the screen remains grey as if it's turning on and off.

I then replaced the wire, set the jumpers to INT and then put in my original A3630 (68030) CPU. The power light blinks and the screen remains grey as if it's turning on and off.

So now I have a real dilemma and not sure what steps to take next

[Kin Hell]

Originally Posted by johntayloruk

Thanks for the tip regarding a Pencil Eraser! Saved my fingers.

So I removed the wire that's bridging the two pins, set the jumpers to EXT and then firmly seated the A3660 CPU. The power light blinks and the screen remains grey as if it's turning on and off.

I then replaced the wire, set the jumpers to INT and then put in my original A3630 (68030) CPU. The power light blinks and the screen remains grey as if it's turning on and off.

So now I have a real dilemma and not sure what steps to take next

Nor me tbh fella, but just to add:

You can read about my suggestions here if you haven't already seen it.
http://www.wonkity.com/~wblock/a4000hard/deadprob.html

It may be the CPU Slot connector on the Mobo. Can you see anything visually wrong with it? - Pins out of line/bent? - I have read about someone picking the CPU Connectors out with a fine point to make them contact better. - Be very very careful doing this. If you over bend the Mobo Slot connections, you could flatten them completely or screw up the CPU Cards pins when inserting the CPU card.

Did you remove all the Fast Ram?

Have you swapped the 2Mb Chip Ram for another Module?

Have you checked the SIMM Sockets are contacting correctly?

A 4 or 8Mb SIMM will show as 2Mb in Chip Ram Slot if you have one to try in exchange. - 2Mb Simm's are hard to source. - Try some of your 4Mb Fast Ram SIMM's in the Chip Ram Socket. (the one nearest the ZORRO Board)

Hard Drive brackets shorting on ZORRO Riser/Daughter board? - There should be an insulation Plastic sheet between Left hand Bracket & back of ZORRO Riser.

I'd also be trying this on the Workbench, IE, out of the Chasssis. - Lay the Mobo on an Anti-static surface, carefully press on any Mobo Socketed Chip/s there might be (Later boards were all surface Mounted), plug in the PSU & the A3630 and try again. - Success would suggest a short between back of Mobo & Chassis or badly seated socketed Chip. - Fail might suggest either CPU Slot is borked, short to Hard Drive Brackets or PSU failure.

*edit*

When the Power Light is flashing, try pressing the CAPS Lock key on & off repeatedly. The Keys light should go "On" & "Off" accordingly. If it Stops going "On" or "Off", this suggests the CPU is not responding. - If for checking the CPU is firmly in place in it's socket, then it has to be something to do with the Mobo's CPU Slot connector.

With the old Battery leak having been cleaned up, there could be some burnt out via's within the mobo's substrate.

[johntayloruk]

Originally Posted by Kin Hell

Nor me tbh fella, but just to add:

You can read about my suggestions here if you haven't already seen it.
http://www.wonkity.com/~wblock/a4000hard/deadprob.html

It may be the CPU Slot connector on the Mobo. Can you see anything visually wrong with it? - Pins out of line/bent? - I have read about someone picking the CPU Connectors out with a fine point to make them contact better. - Be very very careful doing this. If you over bend the Mobo Slot connections, you could flatten them completely or screw up the CPU Cards pins when inserting the CPU card.

Did you remove all the Fast Ram?

Have you swapped the 2Mb Chip Ram for another Module?

Have you checked the SIMM Sockets are contacting correctly?

A 4 or 8Mb SIMM will show as 2Mb in Chip Ram Slot if you have one to try in exchange. - 2Mb Simm's are hard to source. - Try some of your 4Mb Fast Ram SIMM's in the Chip Ram Socket. (the one nearest the ZORRO Board)

Hard Drive brackets shorting on ZORRO Riser/Daughter board? - There should be an insulation Plastic sheet between Left hand Bracket & back of ZORRO Riser.

I'd also be trying this on the Workbench, IE, out of the Chasssis. - Lay the Mobo on an Anti-static surface, carefully press on any Mobo Socketed Chip/s there might be (Later boards were all surface Mounted), plug in the PSU & the A3630 and try again. - Success would suggest a short between back of Mobo & Chassis or badly seated socketed Chip. - Fail might suggest either CPU Slot is borked, short to Hard Drive Brackets or PSU failure.

*edit*

When the Power Light is flashing, try pressing the CAPS Lock key on & off repeatedly. The Keys light should go "On" & "Off" accordingly. If it Stops going "On" or "Off", this suggests the CPU is not responding. - If for checking the CPU is firmly in place in it's socket, then it has to be something to do with the Mobo's CPU Slot connector.

With the old Battery leak having been cleaned up, there could be some burnt out via's within the mobo's substrate.

Thanks for the link, insulating plastic is ok and the power pins don’t poke through.

- CPU slot pins looked ok but I gave them a clean with IPA and adjusted them a little, but didn’t seem to work

- I’ve removed the fast ram and tried with only fastram and that didn’t work

- I’ve tried swapping the 2MB chip ram with my other 4MB Simms, but that didn’t work

- I’m testing without the daughter board or and IDE devices connected and have tried both inside and out of the case, but that didn’t work

- when booting, the caps lock key flashes once. When the grey screen is in, I can press the caps lock key 6 times before the light stops coming on

- The CPU is seated firmly in place

I’ve spent the last 2 days tracing every single connection from the CPU socket, the rom chips and j100, j104including the delay line chip and found no issues

I’m wondering if this overclock someone did might have caused a problem when I put the jumper back on j100 pins 1 & 2. What could this have damaged do you think? Oscillators? Any other chips?

[Kin Hell]

Originally Posted by johntayloruk

T<snip>

- when booting, the caps lock key flashes once. When the grey screen is in, I can press the caps lock key 6 times before the light stops coming on

<snip>

Daughter board is not required for an A4KD to boot.

Grey Screen is part of the Normal boot process.

CAPS Lock light not responding means the CPU is not responding.

If you set J100 & J104 to INT & try the 68030 card, I'd be guessing you get the same result. Yes?

*edit*

Use the Original ROMS for 030 testing.

[johntayloruk]

Very similar yes. With the 68030 card, original ROMs and J100&J104 set to int, the power light blinks 6 times then it cycles. With the 68060 card and J100&J104 set to EXT it stays constant.

[Vypr]

Hmmm, I have an A4000 with a 3660 and BigRamPlus card and didn;t have a problem with them. The 6 flashes on the Power LED definitely sounds like a problem talking to the CPU. I had similar symptoms with a 500+ and an accelerator that turned out to be caused by a broken pin on the accelerator. I ad to replace both the socket on the A500 as I couldn't get the broken pin out and the pins on the accelerator.
Maybe try some contact cleaner on the connectors?

[Mathesar]

"Weird" problems and A3660 can also be caused by an instable +3.3V power supply to the 68060 chip. Can you check the +3.3V with a scope?
See here:
http://eab.abime.net/showpost.php?p=...2&postcount=21

[hooverphonique]

Could you verify you have 25MHz clocks on the center pin of both jumpers when set to int?
I'm wondering if the original tap 3 on the delay line is bad and that's why they used tap 2, and therefore after removing the patch your A3630 doesn't work any longer.