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1MB upgrade for original 520ST...


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#1 blakespot OFFLINE  

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Posted Mon Feb 20, 2012 2:39 PM

How hard is it to get this done? Are there kits floating around? I like the form-factor of the early 520ST and want to take it to 1MB (as opposed to grabbing a 1040 or something).

Thanks.



bp

#2 wood_jl OFFLINE  

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Posted Mon Feb 20, 2012 3:53 PM

This is probably my favorite Atari ST computer, too. However, this is IMPOSSIBLE. NOBODY even seems to have the original text file (or scan) of the procedure that Atari dealers used in the old days....piggybacking the RAM. Best Electronics refuses to do it, saying it's unreliable. I don't understand how it would be unreliable if known good RAM was used, but I admit general ignorance in this matter.

Here's a thread about it from some time ago......

http://www.atariage....0st-to-1mb-ram/

........and in that thread is a link to another thread over at Atari Forum. There may not be a single person in the world who is both able and willing to do this mod, at least for someone else. I suspect one could mail their machine to Europe and get one of those hardcore ST techs to do it, but it would be expensive.

I think you could sent it to Best Electronics and buy a board that takes SIMMS, but it's a horrendous job to even install that - soldered in - for someone who's not a genius. It would probably take at least a couple hundred dollar bills. It's cheaper to get a 1040ST with the meg in it, or 1040STe and then some el-cheapo SIMMS and 4MB.

I'm gravely disappointed in the fact that I'll never have a 4MB original 520ST. I have at least a couple of them. I'm definitely going to keep a minty/boxed one for my collection and as a bit of a curiosity. But for everyday use, I use a 1040ST with a floppy emulator hanging off the side of it. I have 1040STe but haven't even got around to checking it out, except to make sure that it works.


Here's a thread where AA user 'zaxon' said he was developing RAM upgrade board......

http://www.atariage....pgrade-is-done/

but I'm not sure what's going on with him now. Lots of people waiting for other devices ordered since July and still not received at this point. RAM upgrade future looks very bleak for the original 520ST, unless you want to send it to Best Electronics with a blank check. There's another guy ATY Computer (or something) also in California, but I emailed him a few times (a couple years ago or 3) back when I was interested in getting the 520ST upgraded, and he never replied once. I figure: (1) He's not very interested in doing the work, and (2) I'd be a fool to send my stuff to him because of #1.

#3 Fox-1 / mnx OFFLINE  

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Posted Mon Feb 20, 2012 4:38 PM

NOBODY even seems to have the original text file (or scan) of the procedure that Atari dealers used in the old days....piggybacking the RAM.


Did you check your PCB to see where the RAMs are located? Many 512KB ST's just have 4 empty spots where 4 additional RAMs can be fitted to add another 512KB.

https://sites.google...tfm-to-1-mb-ram

#4 wood_jl OFFLINE  

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Posted Mon Feb 20, 2012 4:45 PM

NOBODY even seems to have the original text file (or scan) of the procedure that Atari dealers used in the old days....piggybacking the RAM.


Did you check your PCB to see where the RAMs are located? Many 512KB ST's just have 4 empty spots where 4 additional RAMs can be fitted to add another 512KB.

https://sites.google...tfm-to-1-mb-ram



This is about the original 520ST/520STm......

Posted Image

......and not the 1040ST-looking 520STfm. Actually, I have a 520STfm that had the empty spots and someone (not me) upgraded it to 1MB. But the poor, original 520ST with the external power supply and no built-in floppy drive. Guess I'll use it in case something needs 512k and TOS 1.0 to run.

Edited by wood_jl, Mon Feb 20, 2012 4:46 PM.


#5 Official Ninja OFFLINE  

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Posted Mon Feb 20, 2012 6:18 PM

You can use one of these to upgrade a 520ST to 1mb. It says MP210A on it.
I found this in an original 520STm. It had 2 256K simms installed and the machine was 1mb total.
It worked really good. Some of the tabs for the SIMMS are broken so I had to use a long wire tie
wrapped around the board to keep them in place. Funny, but it worked just fine.
I'm not using this since I don't have that 520 anymore.

Attached Thumbnails

  • 520stupgrade.jpg


#6 wood_jl OFFLINE  

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Posted Mon Feb 20, 2012 6:27 PM

Offical Ninja - was that a "solderless" installation? How was it fastened in? Best warns seriously about using "unreliable solderless" upgrades.

Was that able to fit under the RF shield, or did they ditch that?

That's cool, however. Is it a "Marpet" brand? Why'd you take it out? To sell the machine stock?

Thanks!

#7 Official Ninja OFFLINE  

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Posted Mon Feb 20, 2012 7:20 PM

Offical Ninja - was that a "solderless" installation? How was it fastened in? Best warns seriously about using "unreliable solderless" upgrades.

Was that able to fit under the RF shield, or did they ditch that?

That's cool, however. Is it a "Marpet" brand? Why'd you take it out? To sell the machine stock?

Thanks!


Yes, it is solderless and it says Marpet on one of the little boards. Just the cover of the RF box was removed.
I took it out because something went wrong with that ST. It would beep as if you turned it on with no keyboard attached.
Around the same time I got a 1040STf so I gave the 520 to a friend for parts. That 520 was part of a deal I got screwed by an
AtariAge member. He sold me a lot that I wanted because I was desperate for an STFM. When I got the computers it was just a STFM sticker.
The computer was just an STf. Only good thing I got from the whole lot was an external 720K drive and powersupply.

Edited by Official Ninja, Mon Feb 20, 2012 7:25 PM.


#8 blakespot OFFLINE  

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Posted Tue Feb 21, 2012 12:20 PM

Back in the day a local engineer type performed the 512K upgrade on my 520ST by soldering the chips UNDER the motherboard, to reduce heat. He bent every pin upwards to make the proper contact. Eventually it started to bug out due, presumably, to hairline cracks in the legs. I took it back to the Games 'n' Gadgets where I bought it and they replaced it for me and sent that unit back to Atari.

They must've given a double-take when they saw that board...




bp

#9 wood_jl OFFLINE  

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Posted Tue Feb 21, 2012 4:57 PM

Incredibly, Atari themselves piggybacked the chips on the "520ST+" which was sold in Europe, only. I've never seen one, but I've read about it, I think on atari-forum.

from http://www.old-compu...r.asp?c=20&st=1

The 520 ST+ offered 1 MB of RAM instead of 512 KB. As the main board was designed to provide space for only 512 KB of RAM (16 x 41256 type chips), the second 512 KB bank chips were soldered on top of the original chips.
Apparently, 1 Mb versions were sold as Atari 1040s in Australia...


It's a tough world for 520ST (non-fm) owners in this day.

#10 Chandler OFFLINE  

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Posted Wed Feb 22, 2012 4:39 AM

or maybe this is what you need

never seen one of these


http://rover.ebay.co...984.m1558.l2649

#11 blakespot OFFLINE  

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Posted Wed Feb 22, 2012 8:51 AM

or maybe this is what you need

never seen one of these


http://rover.ebay.co...984.m1558.l2649

Huh... I guess it's a PAL unit, 220v -- would not work well with my NTSC screen and such, here in the states. Right? Nasty case / keyboard on that, but I could swap it into the pristine 520ST case I have here for my 512K unit.



bp

#12 ParanoidLittleMan OFFLINE  

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Posted Wed Feb 22, 2012 9:20 AM

This is probably my favorite Atari ST computer, too. However, this is IMPOSSIBLE. NOBODY even seems to have the original text file (or scan) of the procedure that Atari dealers used in the old days....piggybacking the RAM. Best Electronics refuses to do it, saying it's unreliable. I don't understand how it would be unreliable if known good RAM was used, but I admit general ignorance in this matter.


In old Atari times, before STE arrived, I did several RAM upgrades in 520 ST machines. Piggy back is not really recommended methode. It is so reliable as solderings.
Not skillful man can even damaging chips by overheat. I used mostly boards with RAM, and connected them with lot of wires.
But I can understand that this is today aside - not much interest, too much handwork = high cost. Solderless solutions will not fit in any machine - there are those without sockets.

#13 blakespot OFFLINE  

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Posted Wed Feb 22, 2012 1:24 PM

From the seller of that 520ST+

hi

to be honest i'm not 100% sure if it is PAL i guess it is as it works on a UK TV etc

the external PSU is 220v so you could if you had a USA 110/117v version swap the PSU's but i can't guarantee if it will work on any TV connection via the RF modulator

it will work via a monitor though

hope this helps

let me know if you need any more info

regards

Rupert


I am in the US with NTSC screen. Is this a PAL unit likely?


bp

#14 Chandler OFFLINE  

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Posted Wed Feb 22, 2012 1:32 PM

well it's likely either to be a UK PAL model or European

but if the guy says it works on a UK TV ok then it's most likely UK PAL

the keyboard is a UK layout from the pictures also

#15 Official Ninja OFFLINE  

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Posted Wed Feb 22, 2012 2:36 PM

If you have a USA SC1224 monitor it will display PAL just fine. The image shifts down maybe 3/8 of an inch is all.


#16 mc6809e OFFLINE  

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Posted Mon Feb 27, 2012 4:14 PM

I've used the piggyback method to upgrade two non-atari systems. The idea is to solder all but one pin on each chip to the chip below it. The one unsoldered pin on each chip is the row address strobe (RAS) and is bent up and wired to the unconnected RAS of the device controlling access to DRAM. That's going to be the MMU. It should only take a few minutes to locate the right pin on a schematic.

I'm not sure how this will work on the ST, though. Make sure you've got at least 250ns DRAMs. I know Atari put slower 265ns DRAMs in early STs to save money, but I wouldn't trust slower DRAMs for this project. At 8Mhz, the shifter and 68000 need access to DRAM within 250ns. I'm guessing that Atari was able to get away with the slower DRAM by using the MMU to aggressively steal every available odd memory cycle for DRAM refresh. But with this project, a little extra resistance between pins or a little extra capacitance cause by extra solder might cause errors with slower DRAM.

Good luck.

#17 wood_jl OFFLINE  

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Posted Mon Feb 27, 2012 5:27 PM

If you have a USA SC1224 monitor it will display PAL just fine. The image shifts down maybe 3/8 of an inch is all.


I'm not sure if ALL of the models of SC1224 will do this. I could be wrong, but some further checking is warranted.

The JVC SC 1224 does.

Atari JVC SC1224.jpg


It is possible that the others do as well, but I have no experience with them. I just seem to remember somebody saying at least one of the other models (Goldstar, Samsung) would not.

Could be wrong, but clarification is advised!

:)

#18 Official Ninja OFFLINE  

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Posted Mon Feb 27, 2012 7:40 PM

It is possible that the others do as well, but I have no experience with them. I just seem to remember somebody saying at least one of the other models (Goldstar, Samsung) would not.

Could be wrong, but clarification is advised!

:)


True.

Well, I have two Goldstar models. (I keep wanting to call them LG) Both easily display PAL and NTSC.

So that only leaves Samsung to be verified.

#19 Official Ninja OFFLINE  

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Posted Mon Feb 27, 2012 7:41 PM


It is possible that the others do as well, but I have no experience with them. I just seem to remember somebody saying at least one of the other models (Goldstar, Samsung) would not.

Could be wrong, but clarification is advised!

:)


True.

Well, I have two of the Goldstar model. (I keep wanting to call them LG) Both easily display PAL and NTSC.

So that only leaves Samsung to be verified.



#20 wood_jl OFFLINE  

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Posted Mon Feb 27, 2012 8:49 PM

So that only leaves Samsung to be verified.


credit: These pics are taken from:
http://www.atari7800...1224samsung.htm
(I think AA user "mitch" runs this site - a very nice fellow)

This is the Samsung - the last version of the SC1224

Posted Image
Posted Image


I have never seen one "in person," so I am guessing they are the least popular. In my opinion, they are the least-attractive.

Come to think of it, when I was getting "back into" the ST, I bought my JVC SC1224 from a guy here on AtariAge, and he had a choice of the JVC and the Samsung.
I do believe it was he who told me the JVC would show PAL but the Samsung would not. I wish I could remember specifics! Not many people seem to have this
monitor, it seems?

Back to the 1MB upgrade question..... I just got some more SIMMS for $5.00 for STe/MegaSTe. I know that's typical worth. Amazing, what a difference it is - as in not
a convoluted, expensive, and nearly impossible task to upgrade the earlier machines, hence threads such as this one. Although SIMMs were not popular when these machines
came out, oh how nice it would have been if they would have done it like Amiga did with the 1000 and later 500 where it was still DRAMs, but on a little plug-in card.

From my playing around with 512K 520ST, it still plays most of the games. 1MB 1040ST will still run just about EVERYTHING. There are some games hacked to HD
that really are the only ones that require 2 or 4MB. I think almost everything on floppy disk (or image of floppy disk, if using the HxC Floppy Emulator) will still work on
512K, and (hacks for HD aside) there were NO floppy disk games that will NOT run on 1MB 1040ST. That's why although I love the original form of the original 520ST (before stfm model)
the 1040ST is the one to get on the cheap, and the 1040STe if you can find one and are serious enough to pay about double for one.

The bottom line is that - at least in the U.S. where the entire ST had a relatively small presence - there will NEVER be a practical way to upgrade the RAM. By the time the ST gained
more popularity, the world had moved on to the 1040ST (and 520STfm) form factor. My 520STfm is one of the ones with the blank rows on the motherboard and someone has populated it
prior to my acquisition. I think some of the 520STfm only had the 1 row of RAM and either would need the old-style "piggyback" or an add-in RAM board.

One day in the future (when I get a real job or something) and I have money to throw away, if Best (or somebody) is still around, I'll be tempted to send in an old 520ST for a complete
upgrade and overhaul (re-cap, or whatever else). Would make for a pretty high-dollar machine, no? :)

Edited by wood_jl, Mon Feb 27, 2012 8:50 PM.


#21 Official Ninja OFFLINE  

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Posted Mon Feb 27, 2012 9:17 PM

This is the Samsung - the last version of the SC1224

Posted Image


It is ugly...... I want one.

#22 blakespot OFFLINE  

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Posted Tue Feb 28, 2012 7:46 AM

I have the JVC in use. (I have a Goldstar on the shelf, also.)


Posted Image
my Atari 520ST system by blakespot, on Flickr




bp

#23 Official Ninja OFFLINE  

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Posted Tue Feb 28, 2012 8:33 AM

I have the JVC in use. (I have a Goldstar on the shelf, also.)


Posted Image
my Atari 520ST system by blakespot, on Flickr




bp


Wow. Very nice. What exactly is that box with the disk drives? Is it a stand made to fit two external Atari drives and the monitor or does it have other functions?

Beautiful.


#24 wood_jl OFFLINE  

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Posted Tue Feb 28, 2012 8:15 PM

Wow. Very nice. What exactly is that box with the disk drives? Is it a stand made to fit two external Atari drives and the monitor or does it have other functions?
Beautiful.


Here's another pic from blakespot's photostream......

Posted Image


I actually had one of these, back in the 1986-ish era. They're awesome!!!!! I'd really like to have another! I sold my 520ST system (with it) and got a 1040ST. The SF314 was $299 and it seems to me that the 1MB RAM upgrade being installed by the local Atari dealer ("The Computer Cache, Anchorage, AK) was $199 so it was actually more cost-effective for me to sell the 520ST system and just buy a 1040ST. At the time, the brand-new form factor of the 1040ST (a little long in the tooth by the time the Falcon came around, for sure) was new and exciting!!!!

So I sold mine to a G.I. on Ft. Richardson who had money he was ready to spend. In retrospect, I wish I would have held onto it. The "520 Station" eliminated (at least from visibility) some of the "sea of cables" that the 520ST suffered from, and sort-of gave it a look and feel like the competing Amiga 1000. An Atari computer enthusiast (at least an honest one) in 1985/1986 was actually jealous of the FORM FACTOR of some of the Commodore/Amiga offerings. On the 8-bit front, Commodore offered the Commodore 128D.......

Posted Image

......which gave the "PC-style" case with detachable keyboard. The Amiga 1000......

Posted Image

....of course, offered this from the beginning.

It was a really nice unit, in that the 520 Station offered an almost-the-same experience, for the 520ST owner. It really looked the part, and it cleaned up the clutter.

However, in retrospect, we've all so "had our fill" of PC-style boxes, that they're not novel anymore. The form factor of the 520ST (or the 800XL, for that matter) is truly the novelty, now. The 520 Station is so rare, it was a novelty in its day, and in this day.

The 1040ST form factor - which was copied from the Apple //c and *obviously* copied in the Amiga 500 - will never be uncool. I like the 1040ST (and the Amiga 500 and the //c) for this innovation, but I'd sure like another 520 Station.

#25 oky2000 OFFLINE  

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Posted Wed Feb 29, 2012 6:16 AM

I have these instructions now if anyone still wants them.

I think the whole all in one design was much more useful in the days of the C64/800 etc because people used to play games and put the computer on the floor in front of the main TV in the lounge when they stopped playing Coleco/VCS games. With the ST and Amiga it didn't make as much sense on a desk. Then again I'd rather have an ST/STM and stick two disk drives under the monitor because it isn't much bigger than an original IBM model M keyboard from the early-mid 80s than say the original Macintosh all in one design.




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