Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Nuisance22 on September 04, 2010, 08:43:37 AM
-
I am a complete novice to the world of Amiga and vintage gaming in general as I grew up in the age of retro with the Super Nintendo etc.
I recently picked up an Amiga 500 with a ton of original and blank floppy discs for around £20.
Upon testing it I found that what I would consider the main components work fine. Everything powers up ok and the picture via the RF output box is perfect etc.
When attempting to load discs I stumbled across 2 major problems. Firstly, discs will not fully load due to an error message that pops up saying that the "RAM DISK IS FULL" and secondly neither of the Joystick ports seem to be working meaning I have no control when it gets to this point meaning I just have to switch it off and on again to get back to the main screen.
If someone could offer some repair advice that is jargon free it would more than appreciated. I am not squeamish about taking it apart or soldering etc, I just wouldn't know where to start.
Thanks for reading and I look forward to any replies.
Mike.
-
Hi and welcome here,
Do you have memory expansion under the computer?
Maybe some games require more memory (512k 512k).
What is the name of the game that gives you the message "RAM DISK IS FULL"?
What port is connected to your joystick?
Keyboard in front of you: mouse port is right (Joy1), the joystick port is the left (Joy2).
-
When it turns on with no floppy what screen do you see (what color etc)? it should look something like "kickstart 1.3 insert floppy"
-
It appears that both joy ports first go thru U15, which is a 74HCT157. U15 feeds U4, the Denise chip.
-
It appears that both joy ports first go thru U15, which is a 74HCT157. U15 feeds U4, the Denise chip.
Are you posting on wrong thread or something? :)
-
Start from the beginning.. Four things.
Is this an Amiga 500 and not an Amiga 500 Plus. [ Red light or green light also please]
Do you have the official Amiga Workbench disk. If so which version. Is it green with say 1.2 or 1.3 on it.
When you turn the unit over can you see what is called a trapdoor with a tiny slot. On the base and NOT the side. Can you carefully prize the slot open and if there is anything in there tell us what it is. We are probably going to remove that if its there.
One tiny point... I assume you have a mouse. Don't pull the mouse or joystick in and out while the unit is active. If they are games you are playing, which one in particular gives the error message and describe exactly what you are seeing... ie blue box with message or grey box with message.
-
He said he was going to come back to the Amiga 500 later. So wait till he posts again.
-
Are you posting on wrong thread or something? :)
I thought I was being helpful, I could be deluding myself though.
Yes, I noticed this morning someone posting the same answer to a similar question.
-
If your Amiga 500 has a memory expansion in the trap door underneath, please remove it and check if it has a Barrel type battery. Check that it has not leaked and even if it has not leaked i would still remove it. If it is a coin shaped battery that should be fine and there is no need to remove it.
-
Apologies for late replies. Yes, everyone is being amazingly helpful, I just need a minute to sort out some other consoles I have. I thought this may be a simple fix, but as it seems it is going to take some time to sort out I will post a new thread as soon as I have more time to be more thorough.
Thank you all again, and I will come back with the applicable info you have asked for.
Mike.
-
When attempting to load discs I stumbled across 2 major problems. Firstly, discs will not fully load due to an error message that pops up saying that the "RAM DISK IS FULL" and secondly neither of the Joystick ports seem to be working meaning I have no control when it gets to this point meaning I just have to switch it off and on again to get back to the main screen.
You may have some bad disks or a virus or, as someone mentioned, you only have the base 512k of RAM, and the disks are expecting more. (As an odd aside, RAM DISK is allocated out of RAM as needed, and RAM DISK is always 0% free, 100% full, but it will expand dynamically to fit whatever you copy to it. If you ever check the available space of RAM: it will always read 100% full. Thus, any script that checks it will fail, even when there is enough room. The correct way to see amount of free RAM is the memory stats at the top of the workbench screen.)
Also, what makes you think the joystick ports are bad if you can't play any games or test them? The mouse pointer isn't controlled by joystick, but needs an Amiga mouse in port 1. (You might be tempted to plug a serial mouse in there, as it is a 9-pin port -- DON'T!!! Use ONLY an Amiga-compatible mouse! Otherwise you can damage mouse/joystick ports and CIA chips on the Amiga.)
-
I'm back. Thank you for your help on the ram issue, I will search for an upgrade asap. Just to let you know, I have a compatible mouse. I get nearly no movement out of the cursor, have tried cleaning it and it did nothing. The only thing the mouse picks up is the left and right click. I tried a joystick just to see if I could get movement, but had exactly the same issues.
Right, here is the info I have been asked for......
The Amiga is a 500A, not +, and the power light is green.
I do have the official Workbench Disk, this is version 1.3.2, but on the screen it shows v1.3 when switched on. I also have a copied disk with Workbench 1.3.3 on it.
I have opened the trap door and there is nothing there, no battery or even battery housing to speak of even inside the unit itself.
As for processor, I am taking an educated guess that it is only running 512k as I have tried a couple of games and they all require 1mb of ram or won't go past a blank loading screen. Although having taken it apart, I noticed that the board says 512k/1m Ram. I don't know if this is of any significance?
The board is in immaculate condition, I have noticed people mentioning U15 etc, I located this on the board and it seems to be in good aesthetic condition.
If necessary, I am able to upload some pics to photobucket if it helps?
Mike.
-
Check none of your joystick socket pins have pushed back into the socket.
-
Check pin 7 on the joystick / mouse port for +5V... Without 5V on that pin, your buttons will work ok (and usually a joystick will as well) but a mouse will not register any movement at all. If there isn't voltage there, it may have been shorted and could mean a damaged trace, chip, resistor etc. If there is voltage on the pin, maybe the mouse is defective?
-
OK, have found a revelation. I am able to play certain games absolutely fine via Joystick port 2. Still no luck with Joystick port 1. So the RAM problem is obviously due to lack of it running at 512k and the port 1 doesn't affect 1 player gaming but is obviously still a minor problem at this point. Any suggestions at this point?
Thank you all again for being so helpful, it is honestly more than appreciated.
Mike.
-
Many games only use the game port (port 2) so you wouldn't need to keep unplugging the mouse all the time. The first port is usually only used for joysticks in two player games and such.
For the mouse issue... is it possible you have an Amiga/Atari mouse with the switch in the Atari position? That would cause all movement to be very glitchy.
-
There is a Fusible Resistor beside the Joystick ports on some A500 models, it is a light blue colour and can be blown easily if it's blown there is no power to Pin 7 of CN1 (Mouse/Joystick 1 connector). I think it's labeled R401. (That's Power to Pin 7 of the connector)
It was only on Later A500 motherboards not the earlier releases.
-
OK, have found a revelation. I am able to play certain games absolutely fine via Joystick port 2. Still no luck with Joystick port 1. So the RAM problem is obviously due to lack of it running at 512k and the port 1 doesn't affect 1 player gaming but is obviously still a minor problem at this point. Any suggestions at this point?
Thank you all again for being so helpful, it is honestly more than appreciated.
Mike.
Sounds like all is generally fine. Did you say you had tried the computer with a mouse. Put this in port 1. I wouldn`t mess with anything just yet.
The Amiga OS is 1.3 from the boot screen. I am also assuming the machine boots fine. Once you have confirmed that you have the mouse connected and the machine booted we can check a few other things. Dont mess with anything.. please. The error here is always to go for the hardware when infact it is likely to be .... wait for it... user error. Sorry for that. Opening the machine up, inserting joysticks etc, checking cables and wires just confuses matters.
-
You probably know this, but, a joystick (if plugged into port 1) wont control the workbench pointer like a functional mouse would. The fact that port 2 works with a joystick is a good sign for the ports.
Mice (mouses) are notoriously unreliable. The original Amiga mouse has a ball that turns 2 shafts (x and y axis). Cleaning doesn't always work. Try removing the ball and turning the shafts with your finger, this is easier if you disassemble the mouse. If this works, a new mouse is the way to go.
-
I agree with Tenacious, mice (mouses?) can be ornery creatures.... Always keep one or 2 'backup' mice :)
Always check the 'silly, simple' stuff before doing anything major to your miggy....
I've had decent luck 'refurbishing' Amiga mice, full disassembly, cleaning/degreasing, and using graphite on the pivots of the X/Y sharts... sadly I couldn't save a cool 3-button mouse... :(
-
My mouse problems were 99% connected to broken wires, just next to mouse housing or plug.
-
Many games only use the game port (port 2) so you wouldn't need to keep unplugging the mouse all the time. The first port is usually only used for joysticks in two player games and such.
For the mouse issue... is it possible you have an Amiga/Atari mouse with the switch in the Atari position? That would cause all movement to be very glitchy.
Your a genius!!! The mouse has an Atari/Amiga switch on the bottom. I didn't even realise when cleaning the bloody thing out, lol. It works perfectly now and all it took was less than 2 seconds.
Thank you all so much for your advice and help.
I get the privilege of going through every game I got with it now to see what runs with what RAM. I doubt I will upgrade anything on this due to a tight budget, but I may be back with a list of games I will be looking to sell that aren't compatible if anyone is interested? I'll start an entirely new thread for that one this time, and I'll make sure don't duplicate it, lol.
Thanks again.:)
Mike.
-
Spoke to soon....My floppy drive has completely stopped reading Disks, Sods Law :(
-
A 512kb RAM expansion that goes on the trapdoor usually is sold for peanuts! Prefer one without that pesky metal shield that is only useful to hide the leaking barrel battery!