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DistantStar001

Just Got an Amiga 500, and I have no idea where to start?

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Just got an Amiga 500.  No power supply.  No video cable.  No software.  Got three mice though!

496821880_ScreenShot2021-03-25at6_26_23PM.thumb.png.d5bfb4871f5875632b4a03c42d75d215.png160262882_ScreenShot2021-03-25at6_24_41PM.thumb.png.37ce21caf96986de228bcd71982c6430.png

As you can see it's in great condition, inside and out.  No bulging compactors or missing chips.  Seems to have a memory expansion installed.  Not even that much dust inside. 

 

I have never seen an Amiga before, so I'm not sure where to start (beyond getting a working power supply).  So... Is there anything I should be looking for?  Issues? Peripherals? Games?  Is there any benefit to upgrading or modding it?  I'm very new to this machine, so I really have no idea what I'm doing.  Any advice is appreciated. 🙂 

 

Also, I may have a lead on an original power supply, but Commodore doesn't have the best reputation when it comes to their PSUs.  Should I be looking for an original, or hold out for a modern replacement?  The last thing I want to do is plug it in and fry it!

 

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I believe Ray Carlsen still sells new Amiga PSUs.  He does great work.  

 

Alternatively, the Meanwell RT50B is a good unit.  They even sit perfectly in the original Amiga PSU housing.

 

If this were mine;   open that RAM expansion unit in the trap door and check if it was the battery backed clock version.  There might be leaking battery in there that needs to be removed.  Any damaged traces might be repairable.

 

Do you have any floppy disks with this?   The Amiga 500 has a kickstart ROM to boot the system but you'll need a Workbench disk to get to a usable desktop.   If you power up the system without a disk the drive, you should hear periodic clicking from the disk drive as the system checks to see if you inserted a disk.

 

Get yourself an RGB cable.  The exact one will depend of course on what your display is, the Commodore 1084 was a great monitor, but they are getting hard to find these days.   There are also HDMI options if you want to go that route.  You might want to wait until you know the unit works before paying out for the RGB cable.

 

Get a Gotek or a Lotharek device.  Moving files from a PC or Mac to an Amiga is harder than it is for an ST.  But a solid state disk drive makes it simpler - you can just download ADF images and load them onto an SD card.  If you still want to be able to use the floppy disk, get yourself a boot switcher, so the external Gotek can be drive 0, and the floppy be drive 1.  The external floppy can draw power from the external disk interface, which is a really nice feature and helps to cut down spaghetti.

 

There's some good mods/expansions available.   Assuming your RAM expansion is not damaged by battery acid, you should have 1MB of RAM.  That's enough for most disk-based games, but limited for anything more.   Luckily there are several good expansions available now, such as the Terrible Fire or the ACA500+.   I have the ACA500+ which connects to the expansion port of the left, and brings your total RAM to 8MB, as well as providing two CF-card hard-disk interfaces, so you can use the WHD hard-disk based software options.

 

Another expansion option is the Vampire, which gives you 68060 levels of performance with massive amounts of RAM, HDMI output etc.  It really isn't an Amiga anymore at that point, but can be interesting if you want to explore some of the more demanding software for the machine.  Playing Frontier on the Vampire is quite an entertaining experience.   

 

There are also PowerPC based expansion units, and there is even some software written to use it (Wipeout, Doom, Quake etc), but these seem to be very rare, so unless you are willing to spend a huge sum of money, you might want to leave these for the time being at least.

 

These are great machines, especially if you enjoy playing 16-bit era games.  Have fun and congrats on the acquisition!

 

 

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Oh two more things... perhaps you already know..

 

You have a "Chicken Lips" keyboard.  These are considered to be the best of the Amiga 500 keyboards and fetch quite a premium.  It means your motherboard is probably a Rev 5.

 

Your Agnus chip has a clip over it.  It might be the 8370 version, which is hard coded to NTSC or PAL.   If you're lucky its the 8372 which is PAL/NTSC switchable.  The latter means the unit can soft-switch between 60hz mode and 50hz mode, allowing you play both American and European timing dependent software.  A lot of the best Amiga games were written to the PAL standard, and won't play on a 8370 equipped Amiga.   If you have the 8370, you can replace it with the 8372 - its a drop in replacement.

 

  

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1 hour ago, oracle_jedi said:

If this were mine;   open that RAM expansion unit in the trap door and check if it was the battery backed clock version.  There might be leaking battery in there that needs to be removed.  Any damaged traces might be repairable.

 

Thank you for this!!!  You were right!  Leaking battery.  Fortunately it didn't damage any traces.  I've desoldered and removed it now.  Good thing too, as it seems one of the pins on the connector was pushed out of alignment when it was installed.  I'm hoping that the expansion will still work without the battery.  I really don't want to put a new one in, as they're just disasters waiting to happen.

 

1 hour ago, oracle_jedi said:

Do you have any floppy disks with this? 

Sadly no.  Would it be possible to write disks with another computer?  I have some older Mac's and a 486.  I don't think my Apple II's can handle it though.  

 

1 hour ago, oracle_jedi said:

You have a "Chicken Lips" keyboard.

Good to Know!  

 

1 hour ago, oracle_jedi said:

Your Agnus chip has a clip over it.  It might be the 8370 version, which is hard coded to NTSC or PAL.   If you're lucky its the 8372 which is PAL/NTSC switchable.

Sadly it's the 8370 version.  And given that I'm in the U.S., I'm guessing it's NTSC.  If I want to change that, is this the only chip that needs to be changed?

 

Also, anything else I should be on the lookout for before I power this thing on?

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4 hours ago, oracle_jedi said:

 

You have a "Chicken Lips" keyboard.  These are considered to be the best of the Amiga 500 keyboards and fetch quite a premium.  It means your motherboard is probably a Rev 5.

Just a question: How do you know that the keyboard is "Chicken Lips" type? By the Commodore symbol key maybe?

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Posted (edited)
1 hour ago, Papalapa said:
6 hours ago, oracle_jedi said:

 

You have a "Chicken Lips" keyboard.  These are considered to be the best of the Amiga 500 keyboards and fetch quite a premium.  It means your motherboard is probably a Rev 5.

Just a question: How do you know that the keyboard is "Chicken Lips" type? By the Commodore symbol key maybe?

I just got that.  Apparently (if Google is to be believed) the other kind has two Amiga stylized "A" keys.  I really don't know anything about these.  It's gonna be fun!!!

Edited by DistantStar001

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4 hours ago, DistantStar001 said:

Thank you for this!!!  You were right!  Leaking battery.  Fortunately it didn't damage any traces.  I've desoldered and removed it now.  Good thing too, as it seems one of the pins on the connector was pushed out of alignment when it was installed.  I'm hoping that the expansion will still work without the battery.

Yep, it will. The battery is only for keeping the real-time clock going. Without it, the system time will be reset to 01-Jan-1978 (or the most recent filesystem date if disks are present) when you boot from cold. Not a big deal though if file timestamps aren't important.

 

Quote

I really don't want to put a new one in, as they're just disasters waiting to happen.

If you did want to, you can modify the board by adding a diode, which will let you add a lithium cell like a CR2032 instead. These are far safer, and most holders can be fitted in the same footprint as the battery. Alternatively, many Amiga stores sell small modules that fit in the original battery footprint and contain the diode and the CR2032 holder as a simple drop-in replacement for the NiCd, and there are open-source PCBs as well if you wanted to DIY one.

 

Quote

Sadly no.  Would it be possible to write disks with another computer?  I have some older Mac's and a 486.  I don't think my Apple II's can handle it though. 

No, unfortunately. The Amiga actually has quite a versatile floppy controller that allows it to use many different floppy formats. Its native format stores 880K, more information than the standard 720K of the PC and ST, and the 800K of the Mac, so none of these are capable of writing Amiga disks. The Gotek suggestion is a good one - they can be a little clunky to use, but that can be helped somewhat by getting one with an OLED display and FlashFloppy firmware. You'll pay a bit more than the base Gotek price to get one ready set up like that, but it'll save some fiddling.

 

If you really want to use floppies, there are some additional devices that let a PC read and write Amiga floppies (and other retro formats). Kryoflux is a big one, and Greaseweazle is an open-source alternative based on very cheap Bluepill dev boards. Both use a standard floppy drive with a custom controller and custom software to handle disks.

 

Quote

Sadly it's the 8370 version.  And given that I'm in the U.S., I'm guessing it's NTSC.  If I want to change that, is this the only chip that needs to be changed?

Yep, the 8370 is the NTSC-only version. That's all you need to change, though make sure it's an 8372 or 8372A, because others (including the 8372AB) are not compatible with that revision motherboard. The default OS of the A500 doesn't provide a facility for switching modes in software, but you can switch modes using a special bootdisk, or by modding the machine and putting a switch somewhere to switch modes in hardware (a common mod back in the day). Newer versions of the OS allow switching via a pre-boot menu, but they can also cause problems with compatibility of some very old games.

 

Quote

Also, anything else I should be on the lookout for before I power this thing on?

Not really, they're pretty bullet-proof machines so there's not a lot to worry about. If it's damaged, it's likely caused by some sort of abuse along the way. With no video output, you can still see if it's alive by turning it on and listening for the Amiga "heartbeat" - the floppy drive clicking every couple of seconds as it checks for an inserted disk.

 

As mentioned, getting an RGB cable for it will give you the best image possible without further hardware upgrades, but for testing, the composite output will do fine. It's greyscale only, but that's plenty to make sure the machine works.

 

Welcome to the Amiga world :) It will indeed be fun!

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OK!!!  I got proof of life!  Heart-beat and all!  :-D However, I'm curious about the Video glitching?  Is that normal for the mono out on an old CRT TV?

576604751_ScreenShot2021-03-29at8_55_33PM.thumb.png.937e8e641624eda7e4b206faa5b40231.png1817489158_ScreenShot2021-03-29at8_55_21PM.thumb.png.3950caed4153dcd70d9d432634870d49.png1283842118_ScreenShot2021-03-29at8_54_53PM.thumb.png.a1da4589791de405e588d90e6bdef777.png

 

On 3/26/2021 at 2:31 AM, Daedalus2097 said:

The Gotek suggestion is a good one - they can be a little clunky to use, but that can be helped somewhat by getting one with an OLED display and FlashFloppy firmware.

If I wanted to go through the trouble of flashing the firmware, is there a particular model I should be looking for?  Also, is it possible to use the Gotek to make physical floppies if I wanted to revert to the original drive?

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Seems you've some kind of RAM problem, any of the 16 RAM ICs are faulty or there's something wrong in the related circuitry. If you hear the aforementioned floppy clicking at least could mean most of the computer is working. Can you hit caps key a couple dozen times and check if the led lights on/off all the time?.

Of course ROM/Kickstart could also be faulty, it's the source of the image being displayed...

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Posted (edited)
5 hours ago, jltursan said:

Seems you've some kind of RAM problem, any of the 16 RAM ICs are faulty or there's something wrong in the related circuitry. If you hear the aforementioned floppy clicking at least could mean most of the computer is working. Can you hit caps key a couple dozen times and check if the led lights on/off all the time?.

Of course ROM/Kickstart could also be faulty, it's the source of the image being displayed...

Is there a way to isolate the fault without a boot disk?  For example, if I were to  get a working RAM chip, would piggybacking the chip work to identify the faulty chip?  

 

I was able to confirm that the Caps Lock key does light up.

Edited by DistantStar001
additional information.

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Posted (edited)
14 hours ago, DistantStar001 said:

Is there a way to isolate the fault without a boot disk?  For example, if I were to  get a working RAM chip, would piggybacking the chip work to identify the faulty chip?  

 

I was able to confirm that the Caps Lock key does light up.

So, if the caps lights multiple times, system is mostly working. Do your hear the constant clicking of the floppy drive?

 

Piggybacking could work, just be sure none of the RAM chips are too hot to touch. If they're mostly cold, you can piggyback a good-known RAM IC and check for changes in the image. Btw, you have unplugged the RAM expansion, isn't it?.

 

And indeed, reseat all socketed chips and check also if there's some rust.

 

 

Edited by jltursan

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On 3/30/2021 at 5:03 AM, DistantStar001 said:

If I wanted to go through the trouble of flashing the firmware, is there a particular model I should be looking for?  Also, is it possible to use the Gotek to make physical floppies if I wanted to revert to the original drive?

Goteks are pretty cheap, and are all more or less clones of the original one. There are dozens of different sources both local and from China, so it depends on how long you want to wait versus how much you want to save :) I find it's much nicer to use a Gotek with an OLED or LCD screen rather than the basic 3-digit display they come with by default.

 

The simplest way to create actual floppies is to use the Gotek and internal floppy drive at the same time, then use the Amiga to do a disk copy from the virtual disk to a real disk. This is made much easier by using the Gotek as an external drive, and installing a small mod to allow you to switch between them. Unfortunately, this also needs a cable for connecting the Gotek externally, and preferably a housing, which all adds to the cost and complexity of the project.

 

20 hours ago, jltursan said:

Seems you've some kind of RAM problem, any of the 16 RAM ICs are faulty or there's something wrong in the related circuitry. If you hear the aforementioned floppy clicking at least could mean most of the computer is working. Can you hit caps key a couple dozen times and check if the led lights on/off all the time?.

Of course ROM/Kickstart could also be faulty, it's the source of the image being displayed...

If it's getting to the Kickstart screen, most of the machine is already working - a badly failed CIA wouldn't allow it to get that far. The pattern isn't stored as a flat bitmap in Kickstart, and the code is executing fine, so I would say it's quite unlikely to be a faulty Kickstart. Most of the time when these sorts of glitches appear, it's down to a faulty bit on the custom chip bus. This could be to do with RAM, but I've mostly seen it in relation to the Agnus socket needing a clean. You'll need to remove the clip over the chip and use a proper extraction tool to remove it, but cleaning the contacts in the socket and on the chip could well resolve the issue. The Denise socket is also worth inspecting and cleaning. If these don't resolve it, piggybacking the RAM *might* resolve it, but if it doesn't, that doesn't mean the RAM isn't faulty (ouch - too many negatives, but the point is to not draw too many conclusions from piggybacking). If you have RAM chips lying about then it's an easy step to take, but otherwise I would first get a Gotek set up and run Amiga Test Kit on it. This will show you faulty bits in the RAM test and allow you to narrow down the fault.

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Daedalus2097 is right, the next step to check is the Agnus chip; but beware, visually inspect its socket and look for cracks and if you extract it, do it very carefully.

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Posted (edited)

So, I'm actually very frustrated right now, as this may have become a much bigger repair job.  

 

I tried reseating some of the socketed IC's to see if that might clear up the graphical glitching.  Instead, I got an unstable black screen.  By that point, I had removed the keyboard but the drive was still seeking a disk.  I reinstalled the keyboard and tried again.  This time, Was greeted by a popping noise and no power from the supply.  I've been using a standard PC PSU for this as I was under the impression that they were safe (at least as a temporary solution) as long as the voltages are correct and you don't mess up the wiring.  I didn't.  I checked the voltages with a multimeter and have a visual aid that is color-coded to endure I get it right.  I'm always a little paranoid when it comes to Commodore computers and their power supplies (been 'burned' by too many c64's not to be).  

 

I've tried two other similar PSU's since (I have no directional hearing, so it seemed the best way to find out where the popping cam from), and while both showed correct voltage before I hooked them up to the Amiga, neither would power on after.  In fact, none of them would give any voltage for some time after the Amiga was disconnected.  They've all since returned to working condition.  I can only guess that there's a short somewhere on the Amiga that's triggering a safety in the PSU's.

 

I didn't pull any of the IC's from their sockets, and I didn't do them all.  Just the ROM's and the CIA's.  Each chip was gently lifted a bit before pressing them back in.  I didn't mess with the CPU as it's rather large, and I figured that if that were the culprit, the machine wouldn't boot at all.  Also, I haven't messed with the Angus chip as I don't have the proper tool to remove it at the moment (I've heard the horror stories of cracked sockets).  All others are soldered, so there's not much I can do with them at the moment.  I've repeatedly checked the board for signs of damage but so far I haven't found anything.  I've also removed the RAM expansion with no effect.  

 

I know something went wrong.  Any ideas as to what?

Edited by DistantStar001

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Posted (edited)

Sounds like you've shorted something out, maybe pinched a cable when reinstalling the keyboard, or it's not quite right and is touching something on the motherboard. Did you reinstall the upper shielding? Is that touching anything? Try it without the upper shielding. Did you align the floppy power cable correctly? It's possible to misalign it in some cases, resulting in a dead short on a power rail. The keyboard connector can also be misaligned and cause power issues - disconnect the keyboard and remove it completely and try again, it doesn't need to be attached for the machine to boot.

 

If the PSU was shorted, there's a reasonable chance nothing was harmed and correcting the fault will bring it back to life. Any decent PSU will have short circuit protection, which often makes a regular popping or clicking noise.

Edited by Daedalus2097

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Posted (edited)
10 hours ago, Daedalus2097 said:

Sounds like you've shorted something out, maybe pinched a cable when reinstalling the keyboard, or it's not quite right and is touching something on the motherboard. Did you reinstall the upper shielding? Is that touching anything? Try it without the upper shielding. Did you align the floppy power cable correctly? It's possible to misalign it in some cases, resulting in a dead short on a power rail. The keyboard connector can also be misaligned and cause power issues - disconnect the keyboard and remove it completely and try again, it doesn't need to be attached for the machine to boot.

 

If the PSU was shorted, there's a reasonable chance nothing was harmed and correcting the fault will bring it back to life. Any decent PSU will have short circuit protection, which often makes a regular popping or clicking noise.

You're right.  The +12 and -12 volt lines are shorted to ground on the board.

 

Removing the keyboard (and shield) didn't help, but the connector looked to be offset by one pin.  I didn't mess with the Floppy connector so that should still be fine.

 

I started testing any component that looked to connect power to ground and found that the component circled in the image (at LF1) is shorted, but not the component below it. I'm still probing the board, but this has me wondering if this might be my issue?  

 626869281_ScreenShot2021-04-01at11_19_28AM.thumb.png.24027a6f28ed96bb2068796d46250119.png

 

 

Forgot to mention that this is an issue 5 board.

Edited by DistantStar001
additional information.

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That could be part of it, though it's a strange coincidence to have that failure at the same time as disassembling and reassembling the machine. Did you remove the lower shield too? There's a plastic insulation sheet between the lower shield and the motherboard - if that moves or falls out, you can get shorts between the motherboard and the shield.

The board should still work fine with that capacitor removed, though if you are checking across that component while it's still in the circuit, there's no way of telling whether that's faulty or the short is elsewhere on that rail. So it might be worth checking elsewhere - the 12V and -12V rails are used for the serial port and audio circuitry, for example, so check for shorts in those areas (serial circuitry is near the keyboard connector, including the ...88 & ...89 chips and surrounding components, audio is bottom right section with the ...347 chip, and the area just behind the audio sockets.

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IIRC motherboards have holes on the bottom directly under Agnus. These allow you to push the chip out with some sorta stick. If you still want/need to do that.

 

I've also used thick paperclips to rock those chips back and forth to get them out without using a correct puller. Takes a good number of tries and gentle nudging to not crack the socket.

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Posted (edited)
18 hours ago, Daedalus2097 said:

The board should still work fine with that capacitor removed, though if you are checking across that component while it's still in the circuit, there's no way of telling whether that's faulty or the short is elsewhere on that rail.

Good Point!  So I looked elsewhere. Disassembled the whole thing, and tested the board, and it came back to life!  So I reassembled it, testing power as I added back components.  Long story short, I discovered that the issue is in the floppy drive. The TA774P is blown.  Must have been that popping sound I heard.  Not sure why it went though.  I figure it shouldn't be too hard to replace, provided they're still in production.  In the interim, that Gotek is looking better and better!  

 

4 hours ago, Keatah said:

IIRC motherboards have holes on the bottom directly under Agnus. These allow you to push the chip out with some sorta stick. If you still want/need to do that.

Thanks for this!  I didn't manage to get it out (probably being overly cautious with it), but I did manage to rock it a bit in the socket.  Now the glitching is gone!  :-D 

 

1000716147_ScreenShot2021-04-02at8_20_35PM.thumb.png.9f9cdb68688f9629095f6eae934d879f.png

 

 

Edited by DistantStar001
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Very good. Let's hope that was the problem and that it continues to work.

 

When repairing and restoring vintage boards with sockets of any kind I usually use a bit of DeOxit on all the chips and any contacts/connectors. It's a cleaner, lube, and sealer against further natural oxidation over time. Many techs on AA swear by it.

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Just a note on the Goteks and flashing.

If you don't want to get/use a USB/Serial adapter, you can use a USB MALE to MALE cable to flash it...

https://www.binarydevotion.com/?p=228

I've done both methods (USB serial and USB male/male cable) and they both worked.

 

I'd recommend FlashFloppy firmware over the Cortex one.

 

Enjoy!

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Just out of curiosity, Does anyone know a US seller who carries a ready-made Amiga 500 compatible Gotek?  I've been looking into it, and near as I can tell, it's actually more expensive to piece these together (Gotek, OLED, and mounting bracket) than it is to simply get the ready made one.  Or at least it would if I were in Germany.  In the US, shipping makes it a bit of a wash.  But before I go about importing one from the other side of the world, maybe someone could point me to a more local source?  Or atleast on the same continent?

 

Also, just to reiterate, as I am really new to the Amiga, and I don't think I say this often enough...  Thank you all so much for all the help and suggestions given to me so far.  You've all been very helpful and supportive!!! 🙂 

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On 4/12/2021 at 3:58 PM, DistantStar001 said:

Just out of curiosity, Does anyone know a US seller who carries a ready-made Amiga 500 compatible Gotek?  I've been looking into it, and near as I can tell, it's actually more expensive to piece these together (Gotek, OLED, and mounting bracket) than it is to simply get the ready made one.  Or at least it would if I were in Germany.  In the US, shipping makes it a bit of a wash.  But before I go about importing one from the other side of the world, maybe someone could point me to a more local source?  Or atleast on the same continent?

 

Also, just to reiterate, as I am really new to the Amiga, and I don't think I say this often enough...  Thank you all so much for all the help and suggestions given to me so far.  You've all been very helpful and supportive!!! 🙂 

This person is in Ireland, BUT... I ordered twice PCB keyboard membranes from them and they all arrived fairly fast, 2 weeks I think.

Custom gotek from them: https://www.sordan.ie/product/666/amiga-500-gotek-floppy-drive-emulator-base-oled-flash-floppy/

 

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