<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1433612692542_17835" dir="ltr">Ooops, I read you last message first. I see now you have the same speculative designs on the column as I would have. </div><div id="yui_3_16_0_1_1433612692542_17879" dir="ltr"><br></div><div id="yui_3_16_0_1_1433612692542_17924" dir="ltr">I've largely done the work of building a high performance digital controller that should be widely applicable to most SEM columns. <br></div><div id="yui_3_16_0_1_1433612692542_17974" dir="ltr">Although I might do it differently today using a high speed ADC/DAC board from NI, at the time NI's best solutions were out of reach. Instead I used a high-performance 16 bit parallel NI video capture card and designed an outboard ADC/DAC unit to to feed the card based on a $25 Silicon Design evaluation board. <br></div><div id="yui_3_16_0_1_1433612692542_18345" dir="ltr"><br></div><div id="yui_3_16_0_1_1433612692542_18206" dir="ltr">Beta tests indicated the design worked flawlessly.</div><div id="yui_3_16_0_1_1433612692542_18264" dir="ltr"><br></div><div id="yui_3_16_0_1_1433612692542_18292" dir="ltr">Since that time, the $25 development kit from Silicon Designs seems to have rose to $99, It may not be available any longer. As for the hi-speed video card, not sure it is a current product. Market price may be low as "obsolete", or may have skyrocketed as a crucial and hard to find spare for dedicated applications. <br></div><div id="yui_3_16_0_1_1433612692542_18514" dir="ltr"><br></div><div id="yui_3_16_0_1_1433612692542_18608" dir="ltr">But worse, I can't seem to find the computer with my all-important glue software on it. I think an over-zealous housemate may have tossed the computer "for my own good" as just another piece of "useless junk" I "clearly" did not need, and was confident i would thank him later. Grrr: that fool cost me at least $3000 in patronizing me that way across several pieces of equipment.</div><div id="yui_3_16_0_1_1433612692542_18714" dir="ltr"><br></div><div id="yui_3_16_0_1_1433612692542_18761" dir="ltr">I may well find it. I think i still have the NI card and SD evaluation board front end, breadboarded with support components. <br></div><div dir="ltr" id="yui_3_16_0_1_1433612692542_17823"><span id="yui_3_16_0_1_1433612692542_18839">I should be able to compose a reasonable block diagram and detail my approach to designing the software, if i can't find the software. Because timings were critical, the code I wrote was in assembly language. Not likely more than 100 lines of assembly code, it nonetheless required at least one month of intense coding.</span></div><div id="yui_3_16_0_1_1433612692542_19073" dir="ltr"><br><span id="yui_3_16_0_1_1433612692542_18839"></span></div><div id="yui_3_16_0_1_1433612692542_19093" dir="ltr"><span id="yui_3_16_0_1_1433612692542_18839">In any case it may be worthwhile to compare approaches.</span></div><div dir="ltr"><br><span id="yui_3_16_0_1_1433612692542_18839"></span></div><div id="yui_3_16_0_1_1433612692542_19095" dir="ltr"><span id="yui_3_16_0_1_1433612692542_18839">-Jeff</span></div><div id="yui_3_16_0_1_1433612692542_19097" dir="ltr"><span id="yui_3_16_0_1_1433612692542_18839"></span></div><br> <div id="yui_3_16_0_1_1433612692542_17827" style="font-family: HelveticaNeue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_1_1433612692542_17826" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_1_1433612692542_17825" dir="ltr"> <hr id="yui_3_16_0_1_1433612692542_17865" size="1"> <font id="yui_3_16_0_1_1433612692542_17829" face="Arial" size="2"> <b id="yui_3_16_0_1_1433612692542_18099"><span id="yui_3_16_0_1_1433612692542_18098" style="font-weight:bold;">From:</span></b> John McMaster <johndmcmaster@gmail.com><br> <b id="yui_3_16_0_1_1433612692542_18007"><span id="yui_3_16_0_1_1433612692542_18006" style="font-weight: bold;">To:</span></b> "sem@lists.noisebridge.net" <sem@lists.noisebridge.net> <br> <b><span style="font-weight: bold;">Sent:</span></b> Thursday, June 4, 2015 9:00 AM<br> <b><span style="font-weight: bold;">Subject:</span></b> [Sem] Scrapping Super IIIA<br> </font> </div> <div id="yui_3_16_0_1_1433612692542_18102" class="y_msg_container"><br>Due to vacuum leak problems etc that I'm tired of troubleshooting, I'm <br>going to scrap my Super IIIA and get something more modern / more plug <br>and play. Before I do, does anyone have interest in it? Haven't decided <br>if I'd want some money or it would be free.<br><br>If I do scrap it, most likely what that means is I will e-waste recycle <br>all of the electronics and keep the column / vacuum system for the pipe <br>dream that some day I will fix the leaks and design my own control <br>system for it. (this part is a mere fraction of the entire system size)<br><br>Note: I'm keeping the small ISI SEM (M7) so will not be disposing of my <br>extra filaments, etc<br><br>John<br><br>_______________________________________________<br>SEM mailing list<br><a ymailto="mailto:SEM@lists.noisebridge.net" href="mailto:SEM@lists.noisebridge.net">SEM@lists.noisebridge.net</a><br><a href="https://www.noisebridge.net/mailman/listinfo/sem" target="_blank">https://www.noisebridge.net/mailman/listinfo/sem</a><br><br><br></div> </div> </div> </div></body></html>