CSPPC & A3000 desktop?

[patrik]

@Castellen:

If you have the Amiga Hardware Reference Manual, you will in the "Interface Hardware" section find a description of the protocol and example timings when using a Chinon drive.


/Patrik

[Argus]

@Castellen

Great page!  I did the INT mod many years ago on my A3000 to make the PPC work and I remember it looking just like your photos (I think I got it off another page though).  My machine is a 25MHz 030 model and has Ramsey4/Dmac2/Buster11 combo w/ 16MB zips on the motherboard. It works with a Phase 5 CyberstormPPC no problem.  The original A3K SCSI controller also works but I use it only for an external CDROM, so I had to use active termination on the internal scsi cable.

A suggestion for a hardware guide might be for A1200 motherboard timing modifications for accelerator compatibility.

[Castellen]

Patrik: Thanks for the suggestion.  I've looked in there already and couldn't find the information I needed.  I have the Amiga Hardware Reference Manual 5th printing 1988 edition.  It only contains basic descriptions of the floppy control pins, but lots of details on the system registers and addresses.
Do other editions of the manual have the details you mention?  Any chance the book might accidentally fall into your scanner at the correct page? :-)

I might have to "borrow" the logic analyser from work...


Argus: Good idea, that would be worth documenting.  Haven't done so much with the A1200s, mainly been the "big box" Amigas, so I'll have to do some research.

[billt]

Finally got the thing booting. INT2 and jumper twiddles seem to have made it happier. Ended up toasting the hard drive as it still crashed with the install I had, might not have tried it again after the last QUADCLOCK jumper change, but there was nothing important in there anyway. Got a fresh 3.9 running, and then did something to hose that so I have to try again today. But it was running!

SCSI is currently weird though. I don't have any cables or adaptors or anything for the CSPPC SCSI, and it dodn't want to be happy on the Spitfire board. It's now workingon the 3000 motherboard SCSI, but the termination doesn't make much sense. I don't think ANYTHING is terminated on the chain, internal or external. The drive MIGHT have terminating enabled on it but I of course have no docs for it, and I've removed the other drive that was in this machine earlier, a 52MB drive doesn't do much anymore so no loss... Termination may have been the problem on the Spitfire card as well but it started working this way and I don't want to mess it up! I've heard A3000 termination can be strange, but wow, what fun this has been!

I haven't gotten far enough to see if the PPC works or not though, but at least the 060 part of things seems to be good. I'm hoping this evening I'll have found proof the PPC chip works as well and then I can be happy and try to figure out OS4 on this thing.

[Castellen]

Don't forget you can access the Cyberstorm early setup menu by holding down the Esc key during power up/reset.  You can set many SCSI parameters, memory speed access, etc.
Make sure you use the correct cable and terminations.


Not sure about the Spitfire cards, if they do DMA (direct memory access), you'll need Buster rev 11 to support this.


With motherboard SCSI termination, it's fairly simple:

- If there is nothing plugged into the rear panel DB25 external SCSI connector, then fit the motherboard resistor packs beside the SCSI connector.  Or you can fit a DB25 active terminator directly to the external SCSI connector.

- On the internal SCSI cable, you want termination enabled on the device at the very end of the cable, all devices in between (if any are fitted) should have termination disabled.

-  If you have ultra-wide SCSI devices fitted using a 50 to 68 pin adaptor, you probably have to enable termination on that device, even if it's in the middle of the cable.

- The termination power supplied from the A3000 motherboard often had a fault.  Diode D800 can sometimes be open circuit, or mounted in the PCB backwards.  Check for 5V at pin 25 of the external SCSI connector at the back to make sure the diode is OK.  Device termination may not function correctly if there is no termination 5V supplied from the motherboard.

[billt]

Finally, looks like it's working. Got OS3.9 installed, and ran the WarpOS demo programs found in the WarpOS archive on aminet, so PPC seems to be running as well. Cool! Now I just need to find one of my larger spare SCSI drives so I can install a game or something and actually make use of it. Current drive is a measly 540MB and already mostly full with apps and OS4 beta... But I can relax and be happy now.

[A3KOne]

I always had weird luck with scsi termination on my A3K with the CSPPC board.  In some drive configurations, it would not work if you terminated it. In others, it would not work unless it was terminated.  Sometimes active termination was required, sometimes passive... I experimented until it worked and then left it like it was.

It may sound crazy, but it is true... I think it may have been an issue with using different scsi formats on the same chain.  I had a mix of scsi1/2 and UW.  It was only as fast as the slowest drive in the chain.

[billchase]

Interesting, I am noticing some weird issues with my SCSI
bus on the native 3000 scsi as a result of using a CSPPC.
I wonder if the SCSI chip revision on the motherboard is
a factor in this.  I believe mine is a revision 4?  Maybe
something else, but I do know it is not the latest.  Funny
that your SCSI slowed down to the slowest device.  Normally
you are OK as long as your fastest protocal device are on
the inside of the chain and slowest at the end, at least
it has worked for me.

C Snyder

[Erol]

@Castellen

Hey guys..  i need to do this INT2 modification on my A3000, can someone email me the instructions or post them up on the net,  the links don't work on this thread!

I've not installed the Cyberstormppc card yet.. but i assume i need this modification done.

[alexh]

Installing the _int2 line for the A3000

If you are not comfortable with a soldering iron then you should NOT try this. It would be better if your dealer did the upgrade.

First thing to do is pull the Motherboard of the machine. It is a pain in the butt to work with the A3000 as you will know if you have ever installed any hardware or upgraded any of the custom chips.

Next thing is to look for the FastSlot-CN606 and the CIA 8520-U350. What you need to do is run a wire from U350 Pin 21 to CN606 Pin 82. I use wirewrap type wire, it is thin.

If you look at the back of the Motherboard (the bottom side) at the pins that make up the CN606 you will see 1 of the solder pads that is square. This is Pin 1. With Pin 1 at the top Pin 2 is right and a bit up from pin 1. Pin 3 is right and a bit down from Pin 2. Pin 4 is right and up from Pin 3... then pin 5 starts a new row.

The CIA U350 is across (going left) from the FastSlot. It is about 3 inches from the left side of the Motherboard. It is best to find the chip from the top side then flip it over this way to can be sure you have the right line of pins. Again find pin 1 by looking for the square solder pad. The pin you want is Pin 21. This is diagnal across the chip on the other side.

[billt]

i need to do this INT2 modification on my A3000, can someone email me the instructions or post them up on the net, the links don't work on this thread!

I just followed the second post's web link and it worked fine. Look under Amiga Hardware Repairs section and pick the INT2 repair. It's got some pictures to help make life easier.

[xaccrocheur]

billchase wrote:
Interesting, I am noticing some weird issues with my SCSI
bus on the native 3000 scsi as a result of using a CSPPC.(...)

Man, I'd sure LOVE to have that kind of problems  :-) Where the HELL do ppl find CSPPCs ?? :-?

[Erol]

Thanks to all.  

just found out my board is has the modification already and i didnt know.. wow!!