HigashiJun wrote: ↑Wed Jul 14, 2021 3:01 pmAnd that is a wise recommendation...rubber_jonnie wrote: ↑Wed Jul 14, 2021 9:30 am
With any booster I'd always recommend testing at the original CPU speed first. That way you can verify it is working under standard conditions.
Mega ST2 and booster
- rubber_jonnie
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Re: Mega ST2 and booster
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...
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...
- HigashiJun
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Re: Mega ST2 and booster
Ok, so tried the booster with the SEL pin connected to GND.
There is an improvement with the blitter, as it does not freeze the machine when enabled, but incredibly slows down the display of GEM windows.
When I manage to disable the blitter, everything goes back to normal.
The floppy disk drive is recognized and works great with no disk inserted in, but once I try to access a floppy, I have a row of bombs on the screen.
There is an improvement with the blitter, as it does not freeze the machine when enabled, but incredibly slows down the display of GEM windows.
When I manage to disable the blitter, everything goes back to normal.
The floppy disk drive is recognized and works great with no disk inserted in, but once I try to access a floppy, I have a row of bombs on the screen.
- rubber_jonnie
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Re: Mega ST2 and booster
Might be worth checking the Blitter pads with a microscope to make sure there aren't any solder whiskers shorting them.
Also, do you have a diag cartridge? I used one of these to help track down a floppy problem with a Mega, as it allows you to run tests repeatedly and consistently, something important when tracking down faults.
Has a couple of good Blitter tests as well as a suite of floppy tests. You may also want to test the RAM thoroughly.
I did some FDD repairs in this thread: https://www.exxosforum.co.uk/forum/viewt ... hilit=mega
Might help, worth a try, mine turned out to be the DMA that was giving the floppy problems.
One thing you didn't mention was if it all worked just fine before you did the upgrade? Also, does it work with the other version of TOS that's installed, which I am assuming is 1.04?
Also, do you have a diag cartridge? I used one of these to help track down a floppy problem with a Mega, as it allows you to run tests repeatedly and consistently, something important when tracking down faults.
Has a couple of good Blitter tests as well as a suite of floppy tests. You may also want to test the RAM thoroughly.
I did some FDD repairs in this thread: https://www.exxosforum.co.uk/forum/viewt ... hilit=mega
Might help, worth a try, mine turned out to be the DMA that was giving the floppy problems.
One thing you didn't mention was if it all worked just fine before you did the upgrade? Also, does it work with the other version of TOS that's installed, which I am assuming is 1.04?
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...
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...
Re: Mega ST2 and booster
That sounds really strange. I suggest you continuity check from the CPU to the blitter make sure there is not a bad connection somewhere.. Start with pin 10 of the CPU (DTACK) to pin 27 on the blitter.HigashiJun wrote: ↑Thu Jul 15, 2021 6:13 am There is an improvement with the blitter, as it does not freeze the machine when enabled, but incredibly slows down the display of GEM windows.
When I manage to disable the blitter, everything goes back to normal.
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.
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.
- HigashiJun
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Re: Mega ST2 and booster
Everything is normal when I put back the original CPU (without blitter patch) and TOS 1.04.rubber_jonnie wrote: ↑Thu Jul 15, 2021 9:41 am One thing you didn't mention was if it all worked just fine before you did the upgrade? Also, does it work with the other version of TOS that's installed, which I am assuming is 1.04?
FDD, Gortek or HXC work as expected, and blitter also works perfectly.
I made several loop tests with Gembench and there was no problem at all.
I only have those weird issues with the booster installed.
- HigashiJun
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Re: Mega ST2 and booster
I wlll try the booster with the blitter patch on and also perform a continuity check tomorrow, as I am working today on my new STE board and your V1 plug-in booster...
Re: Mega ST2 and booster
The blitter patch has never been attempted with the booster.. I don't know how it would even be fitted.. but with a recent blitter you don't need it...HigashiJun wrote: ↑Thu Jul 15, 2021 11:10 am I wlll try the booster with the blitter patch on and also perform a continuity check tomorrow,
See ATARI TECHNICAL NOTES ON THE BLiTTER
https://www.exxosforum.co.uk/atari/last/MEGAST/index.htm
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.
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.
- HigashiJun
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- Joined: Fri Jun 19, 2020 7:21 am
- Location: Tokyo
Re: Mega ST2 and booster
I read your interesting article some time ago and that is why I removed the blitter patch from my Mega ST.exxos wrote: ↑Thu Jul 15, 2021 11:29 amThe blitter patch has never been attempted with the booster.. I don't know how it would even be fitted.. but with a recent blitter you don't need it...HigashiJun wrote: ↑Thu Jul 15, 2021 11:10 am I wlll try the booster with the blitter patch on and also perform a continuity check tomorrow,
See ATARI TECHNICAL NOTES ON THE BLiTTER
https://www.exxosforum.co.uk/atari/last/MEGAST/index.htm
I just want to test if only the blitter issue could be solved by adding the patch. I will not even solder it, just make it hold with some masking tape.
Re: Mega ST2 and booster
That really does not sound like a good idea..HigashiJun wrote: ↑Thu Jul 15, 2021 12:35 pm I will not even solder it, just make it hold with some masking tape.
Does your machine work without the booster and without the blitter patch ?
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.
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.
- HigashiJun
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- Joined: Fri Jun 19, 2020 7:21 am
- Location: Tokyo
Re: Mega ST2 and booster
Could it be harmful for some components ?exxos wrote: ↑Thu Jul 15, 2021 1:07 pmThat really does not sound like a good idea..HigashiJun wrote: ↑Thu Jul 15, 2021 12:35 pm I will not even solder it, just make it hold with some masking tape.
Does your machine work without the booster and without the blitter patch ?
The Mega works flawlessly without the booster and without the blitter patch.