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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: nikodr on March 01, 2021, 10:38:21 PM

Title: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: nikodr on March 01, 2021, 10:38:21 PM
Hello...
Is it even possible to install it inside an amiga 1200 and make it functioning without the cpu  card to be sitting out the trapdoor?
I have my 1200 it always had a 68040 apollo with 16mbytes.
Now i tried to open it and didnt work.It showed red screen green screen,and power led flashed for 8 times.

Then i removed apollo 68040 re-seated the simm card i had all worked fine BUT amiga was open with the cover up.When i tried to put the cover of amiga and close it with screws i had the same errors.

It seems i can only work amiga with no problems if amiga is slightly lifted with 4 stuff i put on the corners of the amiga so that it is slightly elevated with no trapdoor installed so that apollo can be a little out of the trapdoor.I tested it with 2.5 hours of whdload playing games and no crashes.

Is there another solution if i dont have a towered amiga?it seems the way they designed the card was bad for the trapdoor .It barely fits at all!
Kind regards
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: Matt_H on March 02, 2021, 04:02:56 AM
My understanding was that all A1200 040 accelerators should always be run with the trapdoor open and/or slightly elevated (you can put larger rubber feet on the bottom case). Did you previously have this system working with the trapdoor closed?
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: NinjaCyborg on March 02, 2021, 11:56:05 AM
You can get replacement trapdoors with air vents in them too. You want a fan in there too. The Warp1260 card allows for a fan to go inside the case without needing to convert to tower so perhaps a similar method can be used, look for Dan Wood's Warp1260 review on YouTube.
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: nikodr on March 02, 2021, 01:56:11 PM
I foud online some stl files for new trapdoors and i will use my 3d printer.

However things are not good now and i have random crashes and guru meditation 8000 000E error randomly while i play games mostly whdload.
The psu i have is the one that gives 25 watts,i only have the 68040 and the ide to cf adapter with a 4giga card inside.Nothing else.
The multimeter shows that 12 line gives 12.5v 5v line gives 4.9 and -12 is -11.6

Could the powersupply make the system unstable?Would i be better using an atx power supply and hack it to power the amiga?

The crashes started today randomly,before that yesterday i used amiga for more than 2 hours with no problems.



Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: Pat the Cat on March 02, 2021, 03:23:29 PM
Apparently if you have only one RAM socket then it will fit into an untowered A1200;-Did the card have another socket added to it?

http://amiga.resource.cx/exp/apollo1260

https://bigbookofamigahardware.com/bboah/product.aspx?id=110

What might be happening is that your simm socket on the top has a loose or dirty fit. Maybe a squirt of DeOxit or WD-40 might clean it out. Even just compressed air from a bicycle pump or something is worth a shot.

Oh yeah, careful what you print the new trapdoor with. PLA not recommended, it will go a bit saggy and sticky over 60C. ("Glass transition point" - not liquid melted but soft.

EDIT: Interesting blog printed fan duct to help with cooling here, but no download I can see. Maybe contact them if interested?

https://amigaalive.blogspot.com/2020/10/new-apollo-124040-cooling-system.html
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: TribbleSmasher on March 02, 2021, 03:37:28 PM
On the Apollo card the CPU sits inside the case. So the culprit is probably the heatsink of the 040 hitting the keyboard and gets pushed downwards. That thing with the rubber feets is for Blizzards, as their CPU faces outwards.
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: Pat the Cat on March 02, 2021, 03:49:11 PM
Fair play, if the trapdoor is away from the CPU and no 2nd simm slot, trapdoor should fit and printed PLA trapdoor with holes should be fine.

I still think it's a dusty / dirty connection somewhere causing the issue with stability.
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: nikodr on March 02, 2021, 05:52:59 PM
I lowered the max transfer rate in the hdtoolbox because i was getting weird crashes and read some forum posts that said that cf should not be higher .Now have fewer crashes.
but they happen too.I can play for 30 minutes and all ok and then i may try to open a folder and get a guru.
I have to clean the apollo card .
Is the 25 watt power supply enough?that is what i cant understand.
25 seems little.
I will post again tomorrow when i have more time to fix it.
I hope i can make it work with no crashes again.Wish it was like back when you just clicked the switch and everything worked with no problems.
It seems old computers psu etc need certain precautions nowdays and if something goes wrong you can get crazy trying to fix it.
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: Pat the Cat on March 02, 2021, 06:50:15 PM
Has it been recapped ever? Board and the A1200?

I'd check out for leaky caps with a bright light and magnifiers.

Also, if you have a floppy drive in the machine, you could try removing it to see if improves stability at all. (They have caps too.

The Max trans thing just reduces the maximum length of file transferred in one go. Probably not that.

Do bear in mind the 68040 isn't very gamer friendly. It's not just games working at all, it's also how they exit back to Workbench..,

.., and what version of 68040.library do you have loaded? Could also be a factor.

EDIT Manual recommendation - don't use a standard power supply. What's it clocked at, 25, 33 or 40MHz? (Half of crystal frequency).
https://bigbookofamigahardware.com/bboah/media/manuals/a_68060.pdf
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: nikodr on March 02, 2021, 08:11:11 PM
Pat the cat thank you for your post :)

It hasn't been recapped before.I checked the capacitors they look ok,no bloated ones but i know that caps may look all right but can have serious issues,i would have to remove them and check the esr but maybe this would be the last measure if all else fails.

Now that you mentioned the power supply : i always had the stock even when i got the apollo card.They never told me to stop using it from the shop i bought it (and it was an official reseller shop of commodore products along with official service for commodore products).
I also had an external tower with a harddrive and cdrom but those got power from another psu on board the tower.

I remember back i used to have a different 68040 library.Now i only have the stock one from the workbench installation a 68040.library.i thought only the 68060 needed to have a different specific library?

Also regarding games i only use whdload ones and the most recent version,i dont play games that are not in the whdload format.i know that many of them could crash or i would have to change the arguments.

So it seems that the problem must be the psu.It seems that it cannot supply the current the cpu needs and then it starts crashing.
But i am amazed that i used it for many years back in the 90ies with the stock one.

I will also try to remove the floppy drive .

Which library of 68040 should i install?

My  workbench is stock i did not install anything else only the latest version of installer from aminet and then i installed whdload,nothing else is installed (besides the games of course) it boots up very fast with all chip memory and fast memory free,and i can play any game i want from those installed.

The hd is a cf card on an ide adaptor, it has 2 partitions of 2gigas so in total 4gigabytes.
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: Pat the Cat on March 02, 2021, 09:28:47 PM
The card has done very well to survive considering it was only warranted for component defect, not damage caused or consequenctial losses caused by using it even during the first six months.

Your CF card probably isn't drawing more power than it ever did BUT Psu's often supply less amperage in old age due to decayed caps (there again).

Also the speed you are running it at has a big impact on energy used and heat generated. As things get hotter they draw more power, and if every component is covered in dust they can't help but heat up.

You could have anything in there for all I know (WB3 had one from Commodore, most folks just download);-

https://aminet.net/package/util/libs/MMULib

The latest "just the flipping library fer Gawdz sake" from 2017 is there, BUT there's a whole lot I don't know about which is best for the Apollo card up on Aminet. For instance with whatever version of kickstart (can be done apparently).

The snag with using anything but the library is that it will take up some RAM. Depends on what your Workbench is set up like. MMULib seems greedy. There was a thread in the last couple of weeks about a seperate "just this" version of the 68040.library from Thomas Richter. I'll have a rummage and edit post later.

And to be honest, never had 68040 in a real Amiga. Used a couple but never as a personal machine. I think I had one for abou
t a week in an A2000 at work.

EDIT: These are "light" versions that save about 200K of RAM. They are kind of optional to MMULib.

http://aminet.net/package/util/sys/Mu680x0Libs

Appears to be the same 68040.library in either one from 2017.

MMULib may seem greedy but is adding a reporting system and offers some proection against out of control sofrware crashing the system. That may appeal to you (You'll still have plenty left out of 16MB to run WHDLOAD I think, even with a shadowed ROM).

Both 68040 and 68060 REQUIRE a custom library to work at all. They're optional on 020 and 030 but still have custom libraries in the MMU release. Enforcer? Exception handling for crashes? That's all in there and more.
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: Matt_H on March 03, 2021, 03:36:23 AM
On the Apollo card the CPU sits inside the case. So the culprit is probably the heatsink of the 040 hitting the keyboard and gets pushed downwards. That thing with the rubber feets is for Blizzards, as their CPU faces outwards.

This is worth examining further. Make sure the accelerator isn't catching on the rim of the trapdoor (or anywhere else), which would subject it to pressure when the case is closed, possibly compromising the connection with the motherboard and causing the errors you described.
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: nikodr on March 03, 2021, 02:41:41 PM
Thank you for your replies.Today i removed apollo to clean it and to check the battery for corossion. it seems clean and ok but i know the battery has to go.Also after removing the apollo from the system i played games for 2 hours and no crashes or anything else.also the capacitors seems to be ok on the motherboard.Otherwise i would have audio distortion or crashes,i know i have to recap it sometime in the future though as these moterboards get older they need care and recap.
So system is fine with stock psu but only for the cf ide card,so if i want to use apollo i have to use another psu with more amperage.
Also regarding the coolling and fan what do ou advice me ?should i remove the small fan it has and put a larger one?and the heatsink?
I am a little bit confused about the heatsink as it is a small one.
the card i have has the 80mhz oscillator so it works on 40mhz.
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: Pat the Cat on March 03, 2021, 03:52:27 PM
A 40MHz 040 sheds over 9W in heat, which is about half your 5 volt rail capacity. I don't know what the power draw all the other chips is too.

The holes in the trapdoor at least allow more cold air in, that's a step in the right direction for cooling at least.

Where it exits the case is also an issue.

The CF card peak drawer is about 100 milliamps, but both it and the floppy drive are fed power over ribbon cables whch add a bit. Even an empty floppy drive needs that or a little more for the circuit board, bearing in mind the relays go "clunk" every few seconds on an Amiga.

The unstable sound might be down to a lot of things. Might be related, might not. Audio needs nice clean + and - 12V to work properly though, it could be related to power.

I think there are a lot of solutions out there for heatsjinks and ducted fan arrangements, not specific to 68040s but maybe adaptable?

I don't even know the voltage of the supplied fan.


You could have a fan on the trapdoor to suck cold air into the case.

EDIT: This project recommends Sunon PMB1212PLB1-A for cooling Xeon's. But it's a blower fan, I think same principle but they would need +12V I think. The ducts for printing aren't relevant I think... Maybe they are. Perhaps a heat sink and a blower fan either side of the chip? That mod I listed had only one.

https://www.thingiverse.com/thing:2623783
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: D00kie on March 03, 2021, 08:10:27 PM
Hi,

    I have been using my Apollo 1240 card since the late 90s and it has a history of instability but I'll describe what's happened in the past and how it is set up now.

Originally in the wedge case, it was stable even with the original 29W power brick.
With the trapdoor cover on, it was unstable, so it ran with the cover off.
The first problem was the CPU fan, which started to get quite noisy. I cut that off and it was okay without cooling but I don't recommend it!
The case was "upgraded" to a tower so there was a lot more "airspace" - running without fan did not concern me that much.
In the tower, the card "flopped around" physically and unless it was in perfect alignment,  the Amiga would not boot.
So I ended up fabricating a bracket to hold the card in tight and perfectly parallel with the motherboard.
Next, replaced the RTC battery and the fan, which is a standard 5v 40MM fan I got from eBay.
Slightly OT - I did add the second SIMM socket to the reverse side of the card and upgraded to 64MB. Choosing SIMMS was tricky.

In summary, card alignment seems to be *really* important, maybe this is most relevant to tower users as there is no playroom in the A1200 trapdoor compartment. The stock PSU is probably not your problem, unless as previously said, it is damaged or worn out. Cooling could be an issue - I think the revision of 040 is important as some need fans at 25MHz and mine at 40MHZ seemed genuinely fine with no fan for years.

On the software side, I used Remapollo from Aminet. I had NO luck with MMULib and other stuff. I tried everything and RemApollo was the only patcher that worked. The 68040 lib used with RemApollo is one of the old Commodore ones which you patch using a command that comes with RemApollo. It's important to follow the instructions precisely! Remapollo is set up to remap the ROM to fast RAM, which speeds up Workbench in a very noticeable way.

I hope this helps - Apollo cards are very temperamental but it was in my budget at the time so I don't criticise the card as much as some Amigans as I could not afford a Cyberstorm. If it was not for the Apollo then I would be having a much less capable 030/25 card today.

EDIT: The CPU cooling fan runs off 12v - it's a 12v 2-pin cooling fan.
 
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: nikodr on March 03, 2021, 11:48:49 PM
Hi,

    I have been using my Apollo 1240 card since the late 90s and it has a history of instability but I'll describe what's happened in the past and how it is set up now.

Originally in the wedge case, it was stable even with the original 29W power brick.
With the trapdoor cover on, it was unstable, so it ran with the cover off.
The first problem was the CPU fan, which started to get quite noisy. I cut that off and it was okay without cooling but I don't recommend it!
The case was "upgraded" to a tower so there was a lot more "airspace" - running without fan did not concern me that much.
In the tower, the card "flopped around" physically and unless it was in perfect alignment,  the Amiga would not boot.
So I ended up fabricating a bracket to hold the card in tight and perfectly parallel with the motherboard.
Next, replaced the RTC battery and the fan, which is a standard 5v 40MM fan I got from eBay.
Slightly OT - I did add the second SIMM socket to the reverse side of the card and upgraded to 64MB. Choosing SIMMS was tricky.

In summary, card alignment seems to be *really* important, maybe this is most relevant to tower users as there is no playroom in the A1200 trapdoor compartment. The stock PSU is probably not your problem, unless as previously said, it is damaged or worn out. Cooling could be an issue - I think the revision of 040 is important as some need fans at 25MHz and mine at 40MHZ seemed genuinely fine with no fan for years.

On the software side, I used Remapollo from Aminet. I had NO luck with MMULib and other stuff. I tried everything and RemApollo was the only patcher that worked. The 68040 lib used with RemApollo is one of the old Commodore ones which you patch using a command that comes with RemApollo. It's important to follow the instructions precisely! Remapollo is set up to remap the ROM to fast RAM, which speeds up Workbench in a very noticeable way.

I hope this helps - Apollo cards are very temperamental but it was in my budget at the time so I don't criticise the card as much as some Amigans as I could not afford a Cyberstorm. If it was not for the Apollo then I would be having a much less capable 030/25 card today.

I 3d printed a small stand to put near floppy to have the keyboard raised and never taouch the  fan or appolo.That seems to solve the case of the card being parallel with the trapdoor closed.That way i have to remove the plastic up part of the amiga.
The machine seems to work ok though without the apollo.
I noticed with stock psu that amiga with only 68020 the psu is really cold and barely gets warm,as soon as apollo comes to play it gets hot after a while,and then it starts getting really hot the 68040.

I hope that by plugging the supply incorecctly before -it didnt go all in and shorted the 12v line to --2v i read on muiltimeter- i hope i didnt kill the card or ram.
I am skeptical if a line that expects to get 12v gets minus voltage if it would die or have effects.
Now that i fixed the  connector the supplied voltage is correct 12.5 for 12v line and 4.9 for the 5v line.

My question is though if the psu stock is still good.It measures 11.7 without load but as soon as it is connected to motherboard it goes to 12.5.
Am i missing something here?i thought usually that psu give higher voltage readings when current is not being drawn and as soon as there is load it drops down the voltage a little.
here i have the opposite senario 11.7 when idle and 12.5 as soon as i connect it to amiga.

2) can someone tell me what kind of simm slot i could buy and use if i wanted to install the second simm slot on the back if i ever had a tower?are these for sale somehow?
i remember someone in an amiga forum posted a thread and sold a modification that allows for apollo cards to see more ram by connecting the missing lines.anyone know anything about this if i could order it from someone?is it still being made?
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: Pat the Cat on March 04, 2021, 05:24:33 AM
1. Whether the CPU has been damaged or not... compatibility with WHDLoad is often untested on a 68040 or 68060 as far as I can gather from their web page. They recommend 68K as "most compatible", and for deveopers creating new WHDLoad versions of games they recommend at least an 030. That is conjectural, perhaps they test recent slaves or not, you could try talking to them about the issue;-

http://www.whdload.de/docs/en/index.html

2. Pin wisee the sockets  are all the same. Presumably a low profile one rather than a vertical one. Whether that lets  you plug in the trapdoor or not is  the key question. I don't know personaly the answer.
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: D00kie on March 04, 2021, 07:50:46 PM
I have also heard the rumour about modifying the 1240 card to allow a 64MB SIMM in the primary SIMM slot. As far as I am aware, this makes the Workbench show 64MB is available, but it is not useable. Everywhere I found says this hack doesn't really work and the only approved way to get the full card's capacity of 64MB is to add the second SIMM slot and install two 32MB SIMMs.

I got the SIMM slot from an electronics supplier online I can't recall the name of. These are really difficult to find now, and I could not find the 90-degree (right-angle) socket; only the 45-degree one which is far more common.
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: nikodr on March 04, 2021, 10:44:06 PM
I have been thinking ways to continue using my amiga.It seems the apollo is not so stable.All amiga forum posts i found clearly state in large percentage that it is a very problematic card to work correctly and setup with the problems of psu and cooling.
I thought about adding an 8mbyte expansion card from amigakit store.I know i will lose the 68040 but then i think for whdload should be ok.
I  searched also about those new aca 68030 cards that once came in the market but noone has them now for sale.Will there ever be a new batch?
I think the 68040 apollo is nice but too cumbersome to really setup and use with not problems.
Are there other cards like the aca around?
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: Pat the Cat on March 05, 2021, 01:49:41 AM
Not in production currently. Could be lack of 030s or profit margin compared to selling 020 cards.

Only other ones I've heard of are Warp 1260 or Vampire, for the A1200.

Bearing in mind your unit is original, you could get most or maybe even all the cost of a Vampire for it.

Is the 68040 soldered in? Makes it harder to upgrade your card to a 1260 (another option).

You definitely want to shop around for lowest profile socket, mouser have a few (22.5 degrees) but there's probably lower angled simm sockets out there.
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: nikodr on March 06, 2021, 12:03:11 AM
It is soldered like it was when i bought it.it does not have a socket.Apollo seems like a mess to use.
I am glad though because once removed the amiga 1200 does not crash and works fine.I have no audio distortion and the caps on motherboard look good.
I wanted to byt an aca but it is unavailable.As for doing a 68060 conversion i think the biggest benefit would be if i had a mediator or something else.Under the os i think the only advantage of 68060 is to decode mp3,something which the 68040 struggles to do under ahi.
I though of getting a delfina clockport card but hese are also unavailable.
Would a mediator take advantage of 68060 ?
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: scuzzb494 on March 06, 2021, 02:50:29 AM
Hi

I am assuming we are talking about the 1240 Apollo Turbo, the sister of the 1260.

First up I have Typhoons, GVP Turbos, Blizzard Turbo, Apollo 1230s and Apollo 1260 and not one of my A1200s has the trapdoor fitted. It was the first thing I was advised and that was remove the trapdoor. Just don't move the Amiga.

Second, throw away your original A1200 PSU. They are useless. I learned this the hard way when I tried to fit a simple 3.5" drive that just never worked. I was told then that any expansion to the Amiga of a significant nature requires the better PSU. I use an A500 heavy brick on all my A1200s with accelerators.

The library is the standard 68040 that came with the Workbench disk.

The card must always be run with the fan. Only the 68060 doesn't need the fan as it has the power modulator.

The cards are a pig and I spent an age when I first had the 1260 tracking down an issue with the shielding. I would open the case and she worked. Shut the case and I'm getting the flshing green light. In the end I found a problem with the bottom left of the shielding. It will be the shielding thats an isse and you need to tape the top fo the board and fold or remove the metal cover next to the board.

I have the manual if you don't have it and I can link to my site if you need it. Apollo themselves say dump the PSU and provide the fan and the original 68040 library. Only the 68060 needs to replace the original 68040.

Also my Apollo wouldn't work with my PCMCIA and Squirrel. And  it wasn't size of memory. The Blizzard with 32MB worked just fine.

Also if you have the battery on the 1240 and its the original they leak.

Also I only change maxtransfer with IDE drives cus otherwise file transfers don't work.

Anyway probably got the complete wrong end of the stick and its another card you are talking about. If so sorry for that.

Question: Do you have the CPU command in C and if so does your startup-sequence have the line CPU CACHE ?

With CPU in C you can configure INSTCACHE, NO INSTCACHE, DATACACHE, NODATACACHE, CACHE or NOCACHE. The manual suggests CPU CACHE. This switches both caches on.

Memory: up to 32mb Standard PS/2 SIM modules. Require FastPageMode access time 70ns or less [ 1, 2, 4, 8, 16, 32 ] More detail in the manual.

Jumpers RAM open OFF and closed ON
Jumpers SCSI Autoboot to scsi open OFF and closed ON
There is a jumper also for the 060 if installed. Jumper CLK should be in position 040.

PS I found this on my 1200 that was causing the shielding to short the Apollo. Very odd.

https://www.scuzzscink.com/amiga/scuzzblog_july18_9/car_sbd_040718_45.jpg
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: Pat the Cat on March 07, 2021, 02:02:14 PM
Long shot - have you done any timing fixes to the A1200 motherboard?

http://www.ianstedman.co.uk/Amiga/amiga_hacks/A1200_Mobo_fix/a1200_mobo_fix.html
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: utri007 on March 07, 2021, 09:40:34 PM
I have used Apollo 68040 accelerator for a years, without a big problems. It just needs a heatsink and fan. Heatsink fits under the keyboard, but fan needs to located to more towards rear of machine.

PS. Timing fixes are mandatory!!
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: nikodr on March 08, 2021, 11:26:19 PM
I have not done any timing fixes ,it was an amiga 1200 from the magic pack of amiga technologies.I think revision e?
I can't use the apollo right now because i dont have a more powerful power supply.I could modify the one i have by cutting the cable and connecting it to an atx.
But i dont want to be aggresive .I removed the apollo right now and it is just with 2mbytes.And power supply is good now.
The think with heat sink what would you use as one?
Also what kind of glue should i use to glue the heatsink?The stock heatsing seems to have the glue it had dried and is not glued now.So if i have to glue it again what substance should i use?
I also check the cpu command and it says all caches are enabled.
Apollo seems a little bit more problematic to setup correctly.But it offers a good boost.
I am on hold right now as i want to purchase a good power supply for amiga.
Also can you help me which is the best device to use to make the amiga possible to use with a vga screen?
I can use it on my android tv with the vga to amiga scart cable that i bought some years ago from amikit but if i try to use a typical vga monitor it only works for workbench if i use high resolution vga but not the pal games (which is almost all whdload).

do you have a suggestion for the best and not too expensive device that can output and promote the pal screen for vga?
Title: Re: Apollo 68040 how to properly install it on a 1200 and close the trapdoor ?
Post by: Pat the Cat on March 09, 2021, 01:24:18 AM
It will do no real harm to use the old heat sink, but a square aluminium one would be better, and a copper one would be best. Weigh the cost. DO NOT BUY A HEATSINK THAT IS TALLER THAN THE ONE YOU HAVE - it must fit under the keyboard.


If the heatsink fell off - that would explain why it keeps overheating.

I would be happier replacing it with a copper or brass heatsink (better than aluminium one). A square one to cover the center of the chip, because that's where the die of the chip is. You can use more than one to cover the area, but a single one about 40mm X 40mm offers a fairly good fit.

As for glue to use, look for "thermal conductive adhesive". Germany makes some of the best you can get. There must be shops there selling the glue to overclock enthusiasts. Also, 3D printer shops often stock the products, (because they are used to glue heatsinks to motor controller boards in 3D printers to help keep them cool). Don't be in a hurry, shop around for the best thermal conductivity, low viscosity (most "dribbly"). You will have to make sure there are no air gaps in the join,

As for a "cheap" VGA connection - all the cheap ones rely on the monitor being able to handle Amiga sync rates, which most monitors do not. The expensive external solutions convert the slower signals to a true VGA standard, and the internal ones are even more expensive. A scan doubler works to a point, but will cause a "torn" display on a fast 50Hz game.

I got no answer for you on that one. I could well be wrong too, perhaps there is a cheap scart-VGA adapter on amazon or similar, that works in all Amiga screen modes,

EDIT: What might work is a cheap scart-HDMI converter, then a cheap HDMI-VGA converter. I have tried the latter, they do work, but generaly with high resolution VGA monitors, 17 inch display or larger (must have over 1,000 vertical lines, 1280 X 1024). I don't have any experience with cheap scart-HDMI converters.