A500 rom switcher - floppy - leaking battery

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jvdbossc

HypnusBE
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ok the pic story about 3 things:

Install the rom switcher
Remove a leaking battery
Trie to fix a not working flop

First will post some pics of the back, before opening it, noticed there are no screws left, but the plastic clicks open with some light force. Did remember not to unscruw the floppy



Well the previous owner was indeed Called Bart, he had about 3 boxes, of software, most of it not orignal, do not understand with a 2.x rom how he did run it.. or might be that i have no flops from that time..

the serials



I read something like asambled in France ... The golden years

The first opening, no rf shield it is gone..





Oops did you see the leaking battery on the mem board?



Well it does no look to bad, it is a memory expansian board, but it is a pitty to let it go. Might have better ones, but did not like the looks of this.



Most of the users here will know what to do, eg replace the battery or have it cut, since I do not know what I am going to do with this board, I decided to cut.

[URL="http://img693.imageshack.us/i/jvb4075.jpg/"]


It did take some more steps then the pics posted, I first used baby wipes, then used alcohol and the rest of the pic tells the story.



Well it is clean anyway. Might be able to sell it for 400 euro's on ebay in 10 years.. ok BAD JOKE :)



Well that is it for the battery problem.

Next pic is the installed old scool rom switcher. The Amiga had a 2.x rom in it, do not wan't it, because I had (have) a600 unwilling to run my software.

I removed it gently with a screw driver in 4 steps, just in case

The 2.x rom is just there on it for keeping, so if it needs to be used some day, it is found where it is needed! :coffee:



This is the end result, the rom swither comes from Amigamaniac.com, had several small installation issues:

(no complaints about the producer, seller whatsoever)

The rom switcher and the A500 gaves bad contact, so cleaning it with electronic spray might be a good idea. Well for the rom switcher it is clearly a good and clean produced product.

The pins of the rom switcher are shorter and less big, so the contact might just be more fragile. The amiga did not work somethimes.

Well cleaned the contacts on the A500 and hot glued the connection to the motherboard (on the socket plastic) , on the plastic, so it would not loosen next opening of the case. (did use not much glue, did not wan't it on the metal inside the socket)

The switch installing is simple:



I simply used a solering iron to make the hole, because my child was already sleaping I did not wan't to make noise. (ok cleaned the soldering iron properly afterwards, and had to remove some unwanted plastic, from the case)

Take another look at the end result:



The provided spacers are glued together to have a double spacer to fix it to the motherboard. Also had to add some insulation material, because the keyboard comes right on it. (metal)

The placement is critical a few milimeters of, and the keyboard does not fit properly!!



Well, this trick, cleaning the floppy heads with alcohol was for me at least, about 99% foul proof, but have to admid, it did not help the floppy drive is not working, will have to dig in big boxes with spares to find a working floppy. Had it to the point to were it reads longer.

Had an amiga 2000 floppy drive to test drive, and yes, the floppy drive is bad.



Rom 1.3

It works stable know after the cleaning of the socket on the motherboard

And for the less legacy stuff:



Sorry that the screen is hard to see, it is black and white, and I did not take care of my camera settings, I was not thinking about the camera at that time.

A proper color screen will be there in the future, using once again Amiga Maniac hardware, and I must admid the 1.3 rom did make a fall from about 1,5 meters..
 
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some minor addon

some minor addon

Realised today it is an A500+, that normally came with 1MB chip ram and kick 2.X (so the previous owner learned to live with it probably)
 
A nice clean up job you're doing there buddy. There's nothing more satisfying than rescuing an ailing board. :D

You did a good job with the ROM switcher, I've done the same myself. I have 3.1 for when I boot from my IDE and fancy a bit of WHDLoad action, plus I have a 1.3 fitted for any troublesome discs. But TBH I haven't found any as yet.

I have a special place in my heart for my 500+, they are lovely machines.
 
Realised today it is an A500+, that normally came with 1MB chip ram and kick 2.X (so the previous owner learned to live with it probably)


Nice machine!

With the additional memory card, what is the total amount of RAM you have?
 
Realised today it is an A500+, that normally came with 1MB chip ram and kick 2.X (so the previous owner learned to live with it probably)

No, it is not exactly the A500+ since it lacks the other half Mb onboard and another TTL plus the clock circuit (with the prone-to-leak battery).

But all of those are easy to add to the board. No need for jumper wires or trace cutting nor any other hack.
 
Realised today it is an A500+, that normally came with 1MB chip ram and kick 2.X (so the previous owner learned to live with it probably)

No, it is not exactly the A500+ since it lacks the other half Mb onboard and another TTL plus the clock circuit (with the prone-to-leak battery).

But all of those are easy to add to the board. No need for jumper wires or trace cutting nor any other hack.

I read somewhere that there was quite a lot of that in later A500 and A2000s. They'd sometimes come with Kickstart 2.04, or ECS Agnus or Denise. My Rev 6.2 A2000 came with an ECS Agnus but only an OCS Denise. I was also quite impressed to discover that swapping the Denise 'Just Worked' -- That was pretty cool.
 
The later 8.0 A500 motherboard revision indeed is a "500+ ready" package: it normally have the 8363 ECS Denise and the latest 8373 2Mb Agnus.

So it is just a matter of soldering the few missing components.
 
floppy

floppy

Well the problem with the floppy is still not solved - still looking for the right spare - should find one anyway.

Yes the open memory slots confuse me to. So just solder mem chips in from a broken A500?
 
Well the problem with the floppy is still not solved - still looking for the right spare - should find one anyway.

Yes the open memory slots confuse me to. So just solder mem chips in from a broken A500?

yes, but you will loose possibility to use that ram expansion
 
is it not chip ram?

is it not chip ram?

Is that not chip ram aka graphics memory?
 
I think it's more than just soldering ram chips into the empty slots, I beleive there are diodes or cap's that need to be installed on the m/board, next to, or near, those chips.
 
Just one .1uF capacitor near each memory chip.

And adding memory chips to the motherboard will not block the trapdoor RAM expansion. Anything with less or equal than 1Mb on the trapdoor will add that 1Mb or less to the available Chip memory (aka graphics memory).
 
And adding memory chips to the motherboard will not block the trapdoor RAM expansion. Anything with less or equal than 1Mb on the trapdoor will add that 1Mb or less to the available Chip memory (aka graphics memory).

im wondering for years how to make it work!!!

from my experience those free IC positions uses same RAS lines as expansion connector.

please look at this thread http://eab.abime.net/showthread.php?t=31816 and if you have some clues how to make it work without adding 3 ICs for muxing those RAS then just tell me.
 
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might have a go

might have a go

Not sure I am going to try, it will of course depend how quick I find the correct spare board and if they get loose with my tools.
 
And adding memory chips to the motherboard will not block the trapdoor RAM expansion. Anything with less or equal than 1Mb on the trapdoor will add that 1Mb or less to the available Chip memory (aka graphics memory).

im wondering for years how to make it work!!!

from my experience those free IC positions uses same RAS lines as expansion connector.

please look at this thread http://eab.abime.net/showthread.php?t=31816 and if you have some clues how to make it work without adding 3 ICs for muxing those RAS then just tell me.

I just gave this a review for about an hour, I will be honest - I am inclined to believe that your Mod is flawless and should work. I believe it is your A500 that has a fault, there seems to be an inconsistent delay happening somewhere in the logic of things thats not quite right...

Due to the inconsitency it screems descrete components failing, most-likely due to age of them on the mothoerboard, however the problem is in tracking this down without a scope would be next to impossible.

saying this it could well be a rouge IC thats just not playing ball to be honest - still its certainly a good mind-bender =D

btw have you tried your Mod on another A500 mobo?
 
ive not tried another board, thats true.
but that A500 runs really well, EVEN with ks 3.1 with switch, multivision500 scandoubler, a590 harddrive ETC. seems to be really stable machine to me :shrug:
 
time to spend next..

time to spend next..

I will have to spend time first with some pc' floppy drives, first evening when I have the time, found various sources of information, converting pc flop to Amiga. Looks like my amiga spares got dead!

Bought a teac fd235hf c810 u 5, but it is missing it's jumpers, it even has no labels on the board for the "0" device. Well 2 bridges for tp1 and tp2 and tp3.

So probably this evening or maybe next, my old pc's will be checked for a donor.

http://www.pitsch.de/stuff/amiga/floppy.htm#A4 (it is in german, but that is not to difficult for dutch people)
 
ok

ok

since the pc floppy drive hack worked I noticed it has only something of 800 k with workbench floppy 3.1 started, however there is memory on the hard drive expansion, not tested yet. So that is not much.

Still waiting for the scsci convertor.

But have a 4000, so would be more than happy that it runs my old games, and transfers adf to flop, without keeping my A4000 busy. (tsgui)

Have contacts in the information technology freelancer world in Belgium, since I am very honest to these guys looking for freelance-employment, (it is an exeption in the recruitment market full of lies and sweet words :thumbsdown:)

So since I have scsci drives in my home it would not be to difficult to find other scsci devices.

i have a couple of good guys willing to sell any scsci (pc) part imaginable at reasonable prices. (or even for free ):whistle: Since they laugh about some requested parts..
 
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