exxos's Atari, Amiga & retro forum

72 PIN SIMM adapter card for the falcon 030. Requires a 16MB simm which gives the maximum 14MB ST-RAM. PCB layout has been carefully designed to use the bulk of the copper area for 5V and 0V rails. Board has a generous 100uF ceramic capacitance for ultimate stability. PCB is assembled and ready to use (16MB simm not included).


STORE LINKS
https://www.exxosforum.co.uk/atari/store2/#0086 (SIMM ADAPTER BOARD)

https://www.exxosforum.co.uk/atari/store2/#0091 (16MB SIMM)

Hi exxos,

First of all, thanks. The board works quite well.

Just a couple of questions though:

1. I tried first with a 9-bit (parity) SIMM. That didn't work at all. Was that a problem with that SIMM, or is this a known characteristic of the Falcon or the SIMM adapter?

2. The solders on the non-flag part of the board can easily come in contact with the PSU + speaker holder part of the shielding. I had to put some isolating tape on the underside of the shielding to prevent those solder points from coming into contact with the shielding. Of course, I discovered this the hard way, but thankfully the only thing that happened was that the Falcon refused to start. It was quite a scare for a few moments.

usul wrote: ↑Sat Nov 09, 2019 9:12 pm 1. I tried first with a 9-bit (parity) SIMM. That didn't work at all. Was that a problem with that SIMM, or is this a known characteristic of the Falcon or the SIMM adapter?

I keep telling people (for years now in fact) not to use parity simms as they malfunction. Nothing drives the parity signals and they start to oscillate and cause all sorts of issues. I even did a video of this happening on a STE.

Also mentioned https://www.exxosforum.co.uk/forum/viewt ... =17&t=1585 point 2.

usul wrote: ↑Sat Nov 09, 2019 9:12 pm 2. The solders on the non-flag part of the board can easily come in contact with the PSU + speaker holder part of the shielding. I had to put some isolating tape on the underside of the shielding to prevent those solder points from coming into contact with the shielding. Of course, I discovered this the hard way, but thankfully the only thing that happened was that the Falcon refused to start. It was quite a scare for a few moments.

This is clearly stated in the store page...

Thanks for the clarifications. I feel dumb not having read either of those notices

Even if top shielding is missing there's outer shielding area that just about touches edge of the memory adapter. I also found it out hard way, fortunately nothing was damaged. Just add little bit of insulation even if you're missing top shielding.