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Re: RAM change to simm ?
Posted: 14 Dec 2018 14:00
by PaulJ
exxos wrote: 14 Dec 2018 11:12
As mentioned *somewhere* I talked about ditching the Falcon RAM boards in place for a 72pin simm socket instead. I am personally leaning towards that idea after the Falcon RAM card "disaster".
There may be some larger DRAM chips we could obtain.. There is the tiny SMT ones I used in my MMU adapter (
http://www.exxosforum.co.uk/atari/last/4MBMMU/index.htm ) Though frankly those are a PITA to solder. Though I am sure I saw some larger types somewhere about a year ago as used on some Acorn RAM boards. So if anyone can find any way to obtain 4 MB of RAM in 1 or 2 chips then let me know.. I am going to hunt around toward and see what I can find..
It still may be worth having the RAM as a addon card as if the DRAM goes off the market, it would render the MB useless if the RAM failed for any reason. In fact the Falcon RAM headers could remain, so that solves future problems. Then DRAM could be soldered onto the motherboard.
I'm with rubber_jonnie on this one. Why not just use the sim off the falcon memory board. I'm ok with falcon memory board too. Soldering surface mount memory is not a good solution. As you bring up we have people that have trouble with dip soldering and if there are sockets for the memory chip you reference they are the same as the sockets we have issuues with. I vote for what we have or a sim socket. The sim in your 4 mb upgrade would work for me. :foldarms:
Re: RAM change to simm ?
Posted: 14 Dec 2018 14:07
by exxos
PaulJ wrote: 14 Dec 2018 14:00
I'm with rubber_jonnie on this one. Why not just use the sim off the falcon memory board. I'm ok with falcon memory board too. Soldering surface mount memory is not a good solution. As you bring up we have people that have trouble with dip soldering and if there are sockets for the memory chip you reference they are the same as the sockets we have issuues with. I vote for what we have or a sim socket. The sim in your 4 mb upgrade would work for me. :foldarms:
I will use the same socket as is used on my falcon RAM boards yes.. but what I am saying those sockets are not cheap to obtain.
mm.jpg
Re: RAM change to simm ?
Posted: 14 Dec 2018 14:18
by exxos
Saying that I do have a stock of 45deg ones which may work...
https://www.exxosforum.co.uk/atari/store2/#0072
Re: RAM change to simm ?
Posted: 14 Dec 2018 14:24
by PaulJ
exxos wrote: 14 Dec 2018 14:18
Saying that I do have a stock of 45deg ones which may work...
Ok with that. :thumbup: :thumbup: :thumbup:
Re: RAM change to simm ?
Posted: 24 Feb 2019 01:40
by exxos
The simm will be added to the H1 when i have chance to update the schematic. I will use the same connector as my falcon ram cards, but I need to make a proper lib for it yet.. The simm will be located under the keyboard so its out of the way.. And the falcon ram card likely removed.. Though I may leave it in place for the H1 as it does really take up any room.
Re: RAM change to simm ?
Posted: 14 Jan 2020 03:51
by Smonson
Here's an alternative supplier (australian) for simm sockets. They sit at a 25-degree angle so should fit under the keyboard, I
think.
https://www.x-on.com.au/DetailsPage/TEC ... HAoYQEjg==
Their price is 7 GBP per unit in 1s, so comparable to Mouser's.
simm72-xon.png
Re: RAM change to simm ?
Posted: 14 Jan 2020 07:59
by terriblefire
My personal preference would be to use TSOP DRAM chips soldered on. More reliable and cheaper than the simm socket. Even at that price.
Plus no users crying that the ancient Simm they’ve cared for since the early 90s that was dug up in an archeological dig in Egypt doesn’t work for whatever reason.
But I seem to be in the minority on this.
Re: RAM change to simm ?
Posted: 14 Jan 2020 10:09
by Smonson
I agree with you @terriblefire. But I can understand a lot of people can't easily solder them on.
Re: RAM change to simm ?
Posted: 14 Jan 2020 10:14
by exxos
This thread is a year old and we changed to the simm.
See this topic instead.
https://www.exxosforum.co.uk/forum/viewt ... =78&t=2368