520ST RAM upgrade question

[ParanoidLittleMan]

This is public thread. No one has right to ask someone to not write in this. What I wrote may be useful for some people. If someone is not ready to read constructive critic should not use public forums, or take much more care what writes.

 

One of biggest errors what ocassional posters do is thinking that after they present their problem, questions they think that then everyone must  then just answer directly on their questions. Even if they are badly formulated, based on not reading/getting some sites, written ...

[Dopy25]

43 minutes ago, ParanoidLittleMan said:

This is public thread. No one has right to ask someone to not write in this. What I wrote may be useful for some people. If someone is not ready to read constructive critic should not use public forums, or take much more care what writes.

 

One of biggest errors what ocassional posters do is thinking that after they present their problem, questions they think that then everyone must  then just answer directly on their questions. Even if they are badly formulated, based on not reading/getting some sites, written ...

I asked for information on a 4MB board from a specific place. You continue to post irrelevant information!

 

That is like if I asked where to purchase a copy of a homebrew Tetris clone for Atari 2600, and your response is "why go that route when you can buy an Adventure clone for Atari 5200?"

 

Your information is not helpful to anyone other than yourself. 

 

And before you get on with "your original topic said easiest way to upgrade RAM." Yes. Yes it did. But as I hope you are aware, I am unable to edit old posts, which is why I followed up and moved on to the board from agranlund. Which is also why I requested you not be a jerk and clutter this thread which is now on PAGE 2, and cluttered with your ridiculous useless replies.

 

In another thread, you posted a seriously dumb topic in a specific sub forum that should never have been there in the first place. It belongs on your own personal page or at the very least, Atari General. I do not need posting advice from someone who cannot follow basic direction. NOW PLEASE GO AWAY.

Edited July 8, 2022 by Dopy25

[+LarryL]

Don’t feed the troll!

there is a nice function here, where you can easily ignore a user ?

[RodLightning]

On topic.. What is the maximum ram that a TOS 1.0 ST will support?  I remember from back in the day that TOS 1.4 or greater was a good idea when upgrading to over 1 megabyte.  Are there limitations with TOS 1.0 or 1.2 with regard to memory?

[Dopy25]

1 hour ago, RodLightning said:

On topic.. What is the maximum ram that a TOS 1.0 ST will support?  I remember from back in the day that TOS 1.4 or greater was a good idea when upgrading to over 1 megabyte.  Are there limitations with TOS 1.0 or 1.2 with regard to memory?

Good question!

 

I honestly do not know. I want to attempt to install the board before upgrading TOS so I will know at some point. At least from a testing standpoint. I did find that there is a way to disable that board to 1MB so if all else fails, I can try that until I upgrade TOS. 

[TGB1718]

I have "piggy back" RAM to 1 MB in my 520STM installed back in the 80's with TOS 1.0.

I don't think TOS limits RAM usage, but I believe it's best to upgrade to 1.04 (which I've done recently)

There are some games that don't seem to run if you have more than 1MB unless you get a "fixed" copy.

[zzip]

Here's a list of TOS changes.   Nothing about fixing >1mb memory support that I see.  

 

https://temlib.org/AtariForumWiki/index.php/History_of_Atari_TOS

[Dopy25]

40 minutes ago, TGB1718 said:

I have "piggy back" RAM to 1 MB in my 520STM installed back in the 80's with TOS 1.0.

I don't think TOS limits RAM usage, but I believe it's best to upgrade to 1.04 (which I've done recently)

There are some games that don't seem to run if you have more than 1MB unless you get a "fixed" copy.

I definitely plan to upgrade TOS but since it "works" right now, the only limitation I am running into is needing more RAM. haha.

Almost every application I run from masteries disk solution stops with an error and says it needs more RAM.

 

I could probably get away with piggybacking, but some of the applications I ran said it needed 4MB so I figured why not go all out.

 

Plus, the board was fairly cheap; I ordered 5 from JLCPCB for $5 after new user discount. Ram chips seem to also be inexpensive at about $15 for 12 of them. I figured 4MB for around the price of piggybacking to 1MB is better. Plus if I can easily build and test them all to working, I can share with others.

[TGB1718]

2 minutes ago, Dopy25 said:

Plus if I can easily build and test them all to working, I can share with others.

That would be nice, my STM even with 1MB still can't use NETUSBEE with memory sticks,

I think it's down to the amount of memory used installing all the drivers.

 

Works really well with my 4MB STE, so if you get this thing working, I would be very interested

in seeing how you did it.

 

[atarian1]

All ST/STEs have a maximum of 4MB of RAM regardless of TOS version. I am not including fancy upgrades that can boost CPU speeds and/or include alternative RAM.

[Dopy25]

I finally got around to putting a board together and it does not work. I figured instead of desoldering the ram from that board, I tried a second one. First it was a black screen with a white border, then it was a black and pink screen with a white border. I realized that I had 2 pins bridged on each board. I fixed that with a braid and cleaned it up on both boards. It made both boards show this pink/black screen. At one point out was a black screen with a weird blue line on the left of the screen. Cleaning up solder fixed that though. I ran out of header pins to try any more without reusing them. 

 

My plan is to get 5 boards working so I soldered sockets to the Atari board for testing purposes. Problem is so far 2 boards do not work, so either 2 chips or 4 chips are bad. I tried replacing the ram on one board but it did the same thing. Can anyone tell what I might be missing here?

 

Using the board design by agranlund with the fix from snark.

 

I ordered more pins in the meantime.

 

 

Now that I think about it, this specific white border was there before I replaced the ram. It's the monitor's fault. 

 

 

Edited August 26, 2022 by Dopy25

[Chri O.]

Did you do this?

The board needs fixing with a bodge wire.

See https://github.com/agranlund/STRam

 

HYB datasheet 5118160BSJ 1M 16-Bit Dynamic RAM.pdf-50/-60 Pin-out.

Edited August 27, 2022 by Chri O.
add ram datasheet

[Dopy25]

57 minutes ago, Chri O. said:

Did you do this?

The board needs fixing with a bodge wire.

See https://github.com/agranlund/STRam

 

HYB datasheet 5118160BSJ 1M 16-Bit Dynamic RAM.pdf-50/-60 Pin-out.

No because I used a "fixed" version posted here:

 

I really wish it were as simple as a missed bodge. I really do.

 

I found more pins and tried a third board. All of the tested chips have that pink/black screen in my last post. 

 

I mention needing the new header pins because when I got the RAM, I soldered everything I had to the boards and had 2 extras. Those were the ones I swapped out in my last post as well. The rest are soldered to boards already. I didn't anticipate having more than 2 bad chips. Especially not 6. I suppose anything is possible though. 

[TimC]

So coincidentally, I also have an older 520STM motherboard.  I saw this upgrade on Adrian's Digitial Basement so I thought I would try it out.  I ordered the boards and actually found an old 72-pin 4MB SIMM with 2 of those chips on there.  I desoldered them and resoldered them on to the Atari memory board.  I need to work up the courage to desolder all the ram on the Atari ST and install this guy.  I may even use a switch for the A9 address line.  I will let you know how it goes.

[Dopy25]

3 hours ago, TimC said:

So coincidentally, I also have an older 520STM motherboard.  I saw this upgrade on Adrian's Digitial Basement so I thought I would try it out.  I ordered the boards and actually found an old 72-pin 4MB SIMM with 2 of those chips on there.  I desoldered them and resoldered them on to the Atari memory board.  I need to work up the courage to desolder all the ram on the Atari ST and install this guy.  I may even use a switch for the A9 address line.  I will let you know how it goes.

Awesome. Mine went well. Take it slow with the ST ram chips. Best way I found was to lay the board flat, and use a heat gun from the bottom. I have a pair of angled tweezers that I set under the ram to let the tweezers do the work once the solder was hot. The light weight of the tweezers will pop the ram up. After that you can use a desoldering unit to pull the solder out. Luckily you only have to clear the top 2 rows holes for all but 2 slots. 

 

I chose not to use a switch for a9 because I don't even know what software malfunctions with 4MB vs 1MB yet. It's all new to me. When I can find a piece of software that causes an issue, I will decide at that time. Everything I am running is from masteries SD card solution right now and I think anything that runs from SD has already been modified and will most likely work with 4MB.

 

 

The issue in my last post was interference. Every board worked well after I moved the MMU lines away from whatever was causing it not to boot. It had to be too close to one of the other connections on the board somehow. 

I posted more about it under hardware:

 

 

 

Edited September 8, 2022 by Dopy25

[TimC]

I have 2x520STM's.  One a C070243 Rev C and the other a Rev H.  The Rev C has a 68 ohm resistor going to the CAS lines on two of the RAM chips.  Is this factory?  I would install the RAM upgrade on this one but not sure if I need these resistors...

 

[TimC]

So I finally got around to installing the 4MB board.  Got through it without issue.  I ended up removing the resistors from the top and relocating to the bottom.  The computer wouldn't boot without them.

 

Ended up putting in the 192k version of EmuTOS.  Turrican II doesn't seem to like it...

[sideburn]

OMG that idiot in here LOL!

 

I have a 520ST that has that old piggy back ram upgrade he was talking bout and it’s failing. So it’s near impossible to try to fix and find which ram is bad so I want to also do this new modern upgrade (as seen on Adrian’s digital basement, don’t add sockets!)…

 

Do we have a best path to both ordering the board as well as sourcing the parts and RAM now?

 

did you use OSH park or PCBWAY?

was the upgrade a success?

 

[snarkdluG]

1 hour ago, sideburn said:

OMG that idiot in here LOL!

 

I have a 520ST that has that old piggy back ram upgrade he was talking bout and it’s failing. So it’s near impossible to try to fix and find which ram is bad so I want to also do this new modern upgrade (as seen on Adrian’s digital basement, don’t add sockets!)…

 

Do we have a best path to both ordering the board as well as sourcing the parts and RAM now?

 

did you use OSH park or PCBWAY?

was the upgrade a success?

 

The PCB is confirmed working as seen here. It doesn't matter where you get your PCB from. Choose whatever.

 

If you got a hot air station, it is cheapest to just get a 4Mb 72 pin SIMM (or a 8Mb 72 pin SIMM if they are easier to find). Get a SIMM module with 2 chip on it. Best is to test the SIMM before you desolder the chip of course. But hard if you don't have a old computer that uses them. Or just buy tested/verified/working SIMMs. 

 

You need 6 pcs of 0.1uF (100nF) 0805 ceramic caps. 2 pcs of 68Ω 0805 resistors and 1 pcs of 33Ω 0805 resistor. And some pin headers (2.54mm/0.1 inches pitch) to connect the RAM and main board together. Some wires as well.

 

MAD9 pin on SMT MMU is different then MAD9 pin on PLCC MMU. But I don't think the old ST ever had SMT MMU?

Edited February 11, 2023 by snarkdluG