exxos's Atari, Amiga & retro forum

Hi All,

So as a bit of a follow on from discussions in other threads, I made up an adaptor based on my ideas (big thanks to Kludge for the original concept) to fit the TF536 in the A600 and be able to close the case, and can confirm it fits nicely and the case closes!
I used an Augat socket which is pretty much the same as the Amphenol one that is used on the Furia. I have used these as replacements on Vampires, and once the socket is slightly modified by sanding the surface off until it is level with the top of the metal pins, it grips the CPU so well that you can lift the entire Amiga by it. But I did include three screw holes to hold it to the HDD cradle holes if required (just need spacers the same height as the PLCC socket, I usually 3D print them).

It _mostly_ works, however I encountered a couple of issues.

1- It won't boot at all if I have the 1MB ChipRAM expansion fitted (it is one of the opensource boards by Sukkoperra). If that fitted I just get a black screen, and cannot even access the early startup menu. If I disconnect the CF card then it doesn't show the kickstart 3.1 screen. If I swap the TF536 out for a 68K DIP, then it works as expected. Tried several of these RAM boards as I have a few made up and same with all of them.

2 - It won't boot unless I disable the CPU caches in the early boot menu. Once that's done it all seems good (unless you enable the caches again). Loads everything I tried, plays Frontier demo, etc. I suspect that the CPU may be the likely cause, its an MC68030RP33 but as usual has a remarked top. I tried another CPU but that ones totally dead and don't have any more to test with as yet. (If anyone has a reliable source then send it my way please). Also tested on my second TF536 with the same CPU and same issue. CF card is setup with PFS3AIO (PFS3DS) as per my normal setups.

I did also notice that the CPLD runs slightly warm, but from others posts on here it appears that several people have noticed this (its genuine from Digikey, not a dodgy Aliexpress one).

If anyone has any other ideas to try until I get some more CPU's in then let me know. I will be releasing the Kicad files for anyone interested once I confirm it works OK.

One bonus, a disk speed test comes out at about 3.5MB/sec, which is over double what I was getting from the onboard IDE.

Cheers,

Lemaru

What firmware do you have in TF536?

arkadiusz.makarenko wrote: 12 Aug 2020 23:11 What firmware do you have in TF536?

Latest RC2 from the TF GitHub

Nice project. Would you be willing to share the pcb files? It may be of some use in getting the TF536 wirking in an Atari STe.

Lemaru wrote: 12 Aug 2020 23:15

arkadiusz.makarenko wrote: 12 Aug 2020 23:11 What firmware do you have in TF536?

Latest RC2 from the TF GitHub

Great piece of work btw.

PhilC wrote: 13 Aug 2020 08:29 Nice project. Would you be willing to share the pcb files? It may be of some use in getting the TF536 wirking in an Atari STe.

Hi, Yeah I will do once I have a working CPU to test it further with. I would rather not release it until I can outline what works and what doesn't to avoid people coming back to me stating it doesn't work.

Nothing has been done different to the work done by Kludge really, other than the PCB layout to make it fit inside the case.

arkadiusz.makarenko wrote: 13 Aug 2020 10:38
Great piece of work btw.

I can't really take credit, as the idea and schematic was originally posted by Kludge.

I was waiting on Kipper2K to release his adaptor to do the same job, but his idea also wouldn't allow the TF536 to fit in the case. So I just based mine on Kludges idea. I thought that some logic would be required for the bus arbitration, but having looked at the original Furia schematics, and some other projects like one that allows you to piggy back a 68010 in the A600, but both of these use the same method as Kludge did to take over the bus.

A little more testing done, and it seems that it will not boot at all, neither to the kickstart screen, nor via HDD, when both a KS3.1 ROM and a 1MB RAM expansion are fitted. I have tried with a few different RAM expansions of different types and same issue.....

Weirdly, KS2.05 boots to kickstart just fine, but as the early startup menu doesn't have the option to disable the CPU caches, I have to boot with no startup-sequence and go from there.

Have the same issue with KS2.05 on my A500, so guessing the CPU cache thing is a dodgy CPU but I can't test further until I get a working CPU, but finding a decent one is a gamble unless paying near to £100 for one that is guaranteed genuine.

Have you tested it with DiagROM? (Sorry if you’ve already said. I’ve been somewhat AFK for a while. Sadly missed out on all the 536 PCB:s as well, so I’m hoping that Exxos will sell more of them :))

Great form factor on the PCB, by the way!

kludge wrote: 13 Aug 2020 15:47 Have you tested it with DiagROM? (Sorry if you’ve already said. I’ve been somewhat AFK for a while. Sadly missed out on all the 536 PCB:s as well, so I’m hoping that Exxos will sell more of them :))

Great form factor on the PCB, by the way!

Cheers Kludge, you done the hard work though. My routing isn't quite as neat as yours was neither.

Waiting on a DiagROM to come as only just ordered one up. I usually use Amiga Test Kit, which serves a purpose but doesn't really cover everything.

Just a bit of an update if anyone is interested.

Finally got some new CPU's. Annoyingly the MC68030RC50C clearly has the original markings visible and is actually an MC68030RC25B. It seems to run OK though this time, with no need to disable the CPU caches.

Results of testing are:

Kickstart 2.05 & 1MB ChipRAM expansion fitted - Works great, haven't run anything that hammers it too hard but no issues noticed in the free time I had. Will test it further when I have more time.

Kickstart 3.1 (No ChipRAM expansion fitted) - As with 2.05 it runs much the same. Will run some more extensive tests when time allows but so far so good.

Kickstart 3.1 & 1MB ChipRAM expansion fitted - Doesn't even attempt to boot, just get a black screen and no drive activity with the TF536 fitted. If I swap it out for a 68000 then all works as it should. Running DiagROM with the TF536 and 1MB expansion fitted, it is detected fine and seems ok. Only becomes and issue with kick3.1 fitted.

So anyone any ideas why a combination of Kick3.1 and the TF536 seems incompatible? I know the TF isn't meant for the A600, but it sure would be nice to get it going as we are pretty limited on accelerators for the A600 other than the Vampire :(

Have a couple of spare boards if anyone wants to try one.

Cheers