exxos's Atari, Amiga & retro forum

HigashiJun wrote: 15 Jul 2021 14:59 The Mega works flawlessly without the booster and without the blitter patch.

Then you do not need the patch, no reason to try and fit it..

exxos wrote: 15 Jul 2021 15:05

HigashiJun wrote: 15 Jul 2021 14:59 The Mega works flawlessly without the booster and without the blitter patch.

Then you do not need the patch, no reason to try and fit it..

It makes sense, but why this bloody blitter behaves weird with the booster installed ?

I think it has nothing in common with DMA, like the FDD related issue which might be solved with a buffer...

HigashiJun wrote: 15 Jul 2021 15:48 It makes sense, but why this bloody blitter behaves weird with the booster installed ?

I really don't know, like I suggested earlier, continuity checked stuff out...

At 8MHz There is no real difference between that and a stock machine anyway.. So I think you have a bad connection somewhere on the booster.

But these strange issues is why I abandoned doing upgrades for original machines because they are just endless trouble unfortunately. MEGA ST range are the worst machines to try and upgrade as well.

I will do the continuity test tomorrow and see what the result is.

I understand you quit doing upgrades for original machines...

exxos wrote: 15 Jul 2021 15:51
But these strange issues is why I abandoned doing upgrades for original machines because they are just endless trouble unfortunately. MEGA ST range are the worst machines to try and upgrade as well.

Guess why all my Megas are unboosted......

Chris, you're the expert, I've known you a long time and
I believe what you say but I've not had the experiences
with my Mega ST like that.

Not long after I got it, I installed the AdSpeed board on
it. Been rock solid there for years, with no problems.

Maybe I just got lucky and got a solid machine? :roll:

PS Usually my luck sucks vacuum hard. :)

@Darklord All machines have their own quirks, as to how severe they are or not.. But all the boosters were tested on my H4 H5 boards and work fine. Is just these mega machines have the most faults over the entire ST range from my experience. Is why only generally recommend the 70789 style boards upgrading as I know what's are on those generally, and they are less problematical than all the other revisions of motherboards.

One note to @HigashiJun I assume you read all of that mega page starting with this information..

exxos wrote: 15 Jul 2021 19:50
One note to @HigashiJun I assume you read all of that mega page starting with this information..

Yes, I read it and it was interesting. I do not not know if there is much difference between Mega2 (my machine) and Mega1 / Mega4 though.

My board is a C100167-001 REV.B with an IMP chip MMU. The RAM is HYB511000A-10.

I have just checked continuity between CPU pin 10 and blitter pin 27.

Nothing to report.

I cannot say the booster does not work, as the machine boots normally. The only issues are FDD access and blitter weird behavior with the booster fitted.

:?

HigashiJun wrote: 16 Jul 2021 05:51 I have just checked continuity between CPU pin 10 and blitter pin 27.

Like I said before, you need to check all pins.. But I think BGACK is routed via the PLD so won't be any connection to MB there.