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Offline LaughyTopic starter

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A500 Upgrades
« on: April 04, 2013, 05:18:12 PM »
Hello,

I've got my Amiga A500 running, (thanks to GadgetUK), it has a 512K trapdoor expansion.

I'm just wondering what upgrades are recommended? I have seen kickstart 3.1 being mentioned. I don't need much more than I've already got, as I just use it for a few games. But it would be nice to make it as good as I could!

I don't have any skills in soldering chips onto motherboards, but have seen there is space for another 512K on the board.

If it's worth adding these chips, where can I find some, and what will it actually do?

Thanks!
« Last Edit: April 04, 2013, 05:20:17 PM by Laughy »
 

Offline LaughyTopic starter

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Re: A500 Upgrades
« Reply #1 on: April 05, 2013, 06:21:24 PM »
Wow, thanks for everyone's fast responses!

Quote from: Oldsmobile_Mike;731261
Haha, watch out, it's a money pit!  ;)


I will try not spend too much at once Mike!!

I do already have an external floppy, so I'm on the way! Lots there I don't understand yet, so will start researching right away. I've got a Rev 6A board, and GadgetUK told me it already has a better Agnus than earlier ones. I'm a total novice when it comes to anything electronic, but enjoying learning about my Amiga!!

What I've got to do now is somehow find out why my comp pro joystick has stopped turning left! I have taken it apart and tried to test the switches for continuity, but not quite sure if that is what I should be doing? Need to find at least one more in any case.

Thanks again, if it's ok to ask a question or two anytime, I'll be very grateful!
 

Offline LaughyTopic starter

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Re: A500 Upgrades
« Reply #2 on: April 05, 2013, 07:05:27 PM »
Indeed it is an 8372A!

I'll have a look into soldering on those pads. When you say more graphically intense, do you mean that even for games I'm familiar with, the graphics will look better? Or for other things I might do on the Amiga?

I doubt I'll be doing anything like you, no way I will understand programming!
 

Offline LaughyTopic starter

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Re: A500 Upgrades
« Reply #3 on: April 05, 2013, 07:06:41 PM »
Would WD40 be good as a contact cleaner? Stupid question I know...:)
 

Offline LaughyTopic starter

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Re: A500 Upgrades
« Reply #4 on: April 05, 2013, 08:59:16 PM »
Quote from: GadgetUK;731402
Yes!  That's fine for joystick microswitches.  What make is it?

Personally I would do the 1Mb chipram mod, thats easy.  Then add a 4 or 8 Mb board from kipper2k.  If you are going to get a HDD (which can be hard to find for a 500) then definitely get the 8Mb board, if you are just going to stick with floppies then 4Mb is all you need, and infact is probably an overkill - that said price difference is hardly anything so I would stick 8Mb in.

If you do get a HDD, then and only then, consider getting 3.1 ROM and a ROM switcher, and if you want to be able to press a key to quit in whdload (software that runs games from HDD) you might want that 68010, I wouldnt bother tbh as you wont be running at stock speed.

You can make that 1Mb chip RAM toggleable with a switch btw, if you dont permenantly want 1Mb chip ram.

ECS denise isnt really needed unless you want to play ECS games, which I think need kickstart 2+ (eg 3.1), so not much point in doing that chip unless you get HDD and 3.1 kickstart etc.

External floppy is a good idea, try to get a cumana - those thing run forever.  If you need a new joystick, look for a good cruiser or zipstick.  I prefer the cruiser myself as its easier to hold but zipstick tend to be more robust.

I would add more RAM to those empty sockets youve got then you would have 1.5Mb chip ram, but it would require soldering many pins.  If you explore that idea make sure to get sockets and solder the sockets in place and not chips - stick the chips in the sockets.  Getting those RAM chips could be tricky - try EBAY or aminet.  I saw a cut off board section just last week that had those RAM chips on it, but they needed desoldering first.

I would be interested to know the model of the RAM on your board, the older revs like mine have 41256, or 51258, 81256 etc.  And there are normally 16 of them, I think yours has 8 and 8 empty spaces?


Joystick is a comp pro, also have a quickshot that down doesn't work on. Sounds like it is also micro switched.
I'll give them a go with the WD40.

I'm ok with the few games that I have for now, they all worked fine before, but I may try to find some that I don't have anymore. But probably they would be fine with stock Amiga, with the trapdoor expansion. It would dbe great fun to add more RAM to the board though!!

The RAM is D424256C, does that sound right? There are 4 chips and 4 spaces on this board.

Here they are:

[ATTACH]2854[/ATTACH]

Would it be hard to find the chips and sockets?
 

Offline LaughyTopic starter

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Re: A500 Upgrades
« Reply #5 on: April 05, 2013, 09:03:18 PM »
Quote from: GadgetUK;731405
Oh oh oh!!!! Before I forget!!! THE upgrade you MUST get in my mind is a HxC Floppy Emulator from Lotharek (google that name). It replaces your FDD with an SD slot, stick a 2gb SD card in for £4 with hundreds of games and you are away. For a 500 its easier than the HDD route imo. They cost around £60 ish but well worth it. There are different models, some with LCD and buttons etc. To get the best result you need to be handy with DIY but you can avoid fitting an LCD etc, its up to you how you mount the thing.
 
Heres the drive in my ST:-
 
See this thread for how I did this, and earlier up the thread is a pic of an amiga with an external unit:-
http://atariage.com/forums/topic/208925-hxc-floppy-emulator-where-to-mount-the-lcd/
 



I like the sound of that! May feel a bit like a crime to cut a hole in my Amiga though!
 

Offline LaughyTopic starter

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Re: A500 Upgrades
« Reply #6 on: April 05, 2013, 09:31:16 PM »
Get confusing readings from the joystick. I've got the multimeter set to 200 ohms, lowest setting. But when testing the good switches, don't get a constant reading when pressing the switch, might begin with 142.7 down to 0.14. But constantly changing. Strange.

Even the bad switch still give the same kind of changing readings.

Tested the fire buttons just in case. Right fire gives the same changing values, but left is completely dead, even though it's not a micro switch, just two metal contacts pushing together. They do make contact, just made sure!
 

Offline LaughyTopic starter

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Re: A500 Upgrades
« Reply #7 on: April 05, 2013, 09:33:55 PM »
Quote from: Oldsmobile_Mike;731412
I believe if you're going to go that route you also need to solder in the resistors?  Might want to double check...


I reckon I could just about handle doing that. Well I'd give it a go...the resistors shouldn't be too hard to find?
 

Offline LaughyTopic starter

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Re: A500 Upgrades
« Reply #8 on: April 05, 2013, 09:53:20 PM »
Quote from: GadgetUK;731415
You aren't making firm enough contacts on the pins, that's all. Press hard and get someone else to move the buttons / directions etc and it will be more constant.
 
EDIT: If its metal contacts and they are definitely making contact then it could be the main wire. Sometimes the wire can work if you bend it certain directions, its worth trying that on the Amiga, plug it in, and hold the button or direction that's not working and bend the main wire at different points to see if it makes any difference at all.
 
Oh, i've just remembered - you swapped your CIA's around, if one was faulty (giving you flashing LED etc) then you could have put the duff one in the position that handles joystick input... If you dont get anywhere with the stick try swapping the stick into the mouse port and see if you can find a game that will use the mouse port and see if that's working with the stick (I suspect it will if your mouse is working), that will prove its the CIA, or you could just swap the CIA's around again and see what happens.  If the stick has been working intermittantly it won't be the CIA it will be the stick btw.  Ideally test another joystick in the port to rule it out but most likely problem is the buttons or the wire.


Damn! The Amiga is in bits as have been doing the retrobriting!

I'll put it together hopefully by Sunday and test the joystick ports, today's sunshine has done wonders, but there is still a bit more to do. The keys especially, casing is nearly there!

Had some help testing the switches just now, bit better readings, though some still changed no matter how hard I pressed.
Up - settled at 0.9
Down - 1.2
Left - No change, still infinity on display
Right - 0.9

Left Fire - stayed on infinity
Right Fire - 2.5

Could plug it all together now, but is it a good idea with absolutely no casing on?!
 

Offline LaughyTopic starter

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Re: A500 Upgrades
« Reply #9 on: April 05, 2013, 09:57:40 PM »
Quote from: GadgetUK;731417
Will be easy to find resistors, the really hard thing to find are the RAM chips at reasonable price.  £5 is cheap really, I looked at the old 41256's for my model and they were £3 each and 16 are required for my version =O   Luckily because I used to be in the industry I found 80+ of them in my IC collection =)


Oh yeah, a fiver is absolutely fine! You can't buy that kind of luck!
 

Offline LaughyTopic starter

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Re: A500 Upgrades
« Reply #10 on: April 07, 2013, 07:26:11 PM »
Hi,

Thanks to everyone for their suggestions! I'm more confused now than before, mainly due to being at least 20 years behind you all in electronic experience!

I thought I was doing pretty good, when I put the trapdoor expansion in in 1990! Haven't done anything with computers since...

I will look up as many of your suggestions as my brain can handle, and definitely do some of them. I'd better start with the ones that don't require any soldering on the motherboard. I'd better keep it simple, I quite like using the floppies still, for the proper retro feel. But having a different drive with tons of games on it does appeal!

I'm just happy to be using my beloved Amiga again!

Thanks!