Mega ST2 and booster

Problems with your machine in general.
User avatar
exxos
Site Admin
Site Admin
Posts: 23437
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: Mega ST2 and booster

Post by exxos »

HigashiJun wrote: Thu Jul 15, 2021 2:59 pm 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..
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
User avatar
HigashiJun
Posts: 1175
Joined: Fri Jun 19, 2020 7:21 am
Location: Tokyo

Re: Mega ST2 and booster

Post by HigashiJun »

exxos wrote: Thu Jul 15, 2021 3:05 pm
HigashiJun wrote: Thu Jul 15, 2021 2:59 pm 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...
User avatar
exxos
Site Admin
Site Admin
Posts: 23437
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: Mega ST2 and booster

Post by exxos »

HigashiJun wrote: Thu Jul 15, 2021 3:48 pm 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.
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
User avatar
HigashiJun
Posts: 1175
Joined: Fri Jun 19, 2020 7:21 am
Location: Tokyo

Re: Mega ST2 and booster

Post by HigashiJun »

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

I understand you quit doing upgrades for original machines...
User avatar
rubber_jonnie
Site Admin
Site Admin
Posts: 10387
Joined: Thu Aug 17, 2017 7:40 pm
Location: Essex
Contact:

Re: Mega ST2 and booster

Post by rubber_jonnie »

exxos wrote: Thu Jul 15, 2021 3:51 pm
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......
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
User avatar
Darklord
Posts: 898
Joined: Wed Sep 20, 2017 1:41 pm

Re: Mega ST2 and booster

Post by Darklord »

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. :)
Welcome To DarkForce! www.darkforce.org "The Fuji Lives.!"
Atari SW/HW based BBS-Telnet:darkforce-bbs.dyndns.org 1040
User avatar
exxos
Site Admin
Site Admin
Posts: 23437
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: Mega ST2 and booster

Post by exxos »

@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..

Capture.JPG
Capture.JPG (90.24 KiB) Viewed 2878 times
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
User avatar
HigashiJun
Posts: 1175
Joined: Fri Jun 19, 2020 7:21 am
Location: Tokyo

Re: Mega ST2 and booster

Post by HigashiJun »

exxos wrote: Thu Jul 15, 2021 7:50 pm
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.
User avatar
HigashiJun
Posts: 1175
Joined: Fri Jun 19, 2020 7:21 am
Location: Tokyo

Re: Mega ST2 and booster

Post by HigashiJun »

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.

:?
User avatar
exxos
Site Admin
Site Admin
Posts: 23437
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: Mega ST2 and booster

Post by exxos »

HigashiJun wrote: Fri Jul 16, 2021 5:51 am 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.
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
Post Reply

Return to “HARDWARE ISSUES”