PAK issues

[rubber_jonnie]

Just a reminder, there is a list of 020 PAK jumper settings in the PAK 68/20 repository here: https://www.exxosforum.co.uk/forum/viewt ... ory#p16799

[exxos]

I burned new UK TOS for my pak , RJ had it working in his machine. I think the original was German .

Looks like I had German TOS when I did my benchmarks https://www.exxosforum.co.uk/forum/viewt ... f=42&t=571

I don't know is any patches were done with the German TOS or not. I don't know how much testing was done by RJ... But I never got it to boot again after that benchmark.. I'm sure I had UK TOS working before I took the pak out if my board. Either way, as it worked in RJ machine, not mine, then UK TOS should at least boot.

I half think though this is all down to bad PCB layout. It seems very hit and miss which cpus work. I think my problems started when I add more caps on the back of the CPU. I removed them later but was ever able to boot again.

I sent all my 020 CPUs to RJ also to test where most of them worked for him. For me, there was I think one or 2 CPUs which would just give a row of bombs on the screen . that was as good as I could get it. Most of the CPUs were just totally dead to me. I also recall frank had issues with only some cpus working. Which if why I brought my CPU from him as known working. Though it got mixed up with my others or lost.

[PhilC]

Ok, I have 5 mins, hopefully post photos of boards later but for no the jeds are:

030:
U1 p13_50d.jed
u2 p2_51.jed 32-50mhz
u3 p3_puk_a.jed
u4 v4_50ac.jed
u5 v5_51a.jed
u6 p6_st.jed

020:
I dont have version nos for these but have tried U12_21 and U12_24

both have 32mhz oscillators on them.

[rubber_jonnie]

I burned new UK TOS for my pak , RJ had it working in his machine. I think the original was German .

Looks like I had German TOS when I did my benchmarks https://www.exxosforum.co.uk/forum/viewt ... f=42&t=571

I don't know is any patches were done with the German TOS or not. I don't know how much testing was done by RJ... But I never got it to boot again after that benchmark.. I'm sure I had UK TOS working before I took the pak out if my board. Either way, as it worked in RJ machine, not mine, then UK TOS should at least boot.

I half think though this is all down to bad PCB layout. It seems very hit and miss which cpus work. I think my problems started when I add more caps on the back of the CPU. I removed them later but was ever able to boot again.

I sent all my 020 CPUs to RJ also to test where most of them worked for him. For me, there was I think one or 2 CPUs which would just give a row of bombs on the screen . that was as good as I could get it. Most of the CPUs were just totally dead to me. I also recall frank had issues with only some cpus working. Which if why I brought my CPU from him as known working. Though it got mixed up with my others or lost.

exxos, pretty sure your PAK/20 had UK TOS when I tested it, as the menus etc were in English, not German. I tested your board quite a bit with various games and Gembench and it ran just fine, well at least until I swapped out the CPUs for testing, at which point some worked, some didn't, and if I recall, I marked the bad ones as such.

It was, as my PAK is, sensitive to PSU output though, so I had to make sure I used a good re-capped PSU with it.

The other thing that I did, which may have been different to you (both), is removing the old 68K CPU and installing a socket in it's place. The jumpers on my PAK are set to assume no original CPU.

I did also try it in a board with a 68K CPU still installed, but with a socket on top, but it was massively unstable. By that I mean sometimes it would boot, but when trying disk access of any sort, it was never long before it hung or gave me varying displays of bombs. And yes, I did change the jumper settings. I do need to try this board again without the Blitter installed to be fair.

As soon as I moved it back to the original test board with no original CPU, all back to stable and lovely.

The other slight difference between my board and exxos' was that his was an earlier revision and required some bodge wires, whereas mine was later and didn't need them according to Frank.

One other point that Frank made when I built mine (Also Redhawk 668) was that it won't work with the Blitter installed.

Oh, and one last thing with youurs exxos, it wouldn't work with an FPU installed. I had a 40Mhz 68882 that I run in mine which I tested in yours at CPU speed, 32Mhz and 40Mhz, and no joy. Ran a treat in mine.

[PhilC]

Thanks RJ, will try all those things later on as well as getting the other details for pakman

[pakman]

In your MegaST, was there a 68000 installed in parallel with the PAK?

[PhilC]

In your MegaST, was there a 68000 installed in parallel with the PAK?

I tried with and without the 68000 being installed

[pakman]

When installed, was the the 68000 mounted on top of the PAK?
And did everything work properly with the 68000 enabled, and the PAK being disabled?

[PhilC]

When installed, was the the 68000 mounted on top of the PAK?
And did everything work properly with the 68000 enabled, and the PAK being disabled?

It was mounted on top but still didn't work but then I've not tried it since, so will re-try it too with another 68000

[pakman]

No further try and error.. we will start from scratch!
Let us go for the PAK030 first. I am waiting for your jumper settings and your photos of the PAK.