Image credit - ebay
From issue #2 of Byte Magazine - 1975
Tuesday, September 10, 2013
Friday, July 19, 2013
FYI, from Mike Willegal / Newsgroup posting
I thought this was fairly important so wanted to share this here -- From Mike Willegal (willegal.net)
FYI,
Amphenol 78S4 sockets and 86CP4 plugs were the "standard" connector used for connecting the power supply to the chassis and peripherals on the SCELBI. Current supply is limited and prices are rising. Corey tells me that Leeds Radio in New York told him that the sockets went out of production last year. The socket can be currently found at a alliedelec.com and the plug can be found at tedss.com (tedss also has a ebay store). Cost is approximately $9.00 each. Last year the sockets were under $5 and I saw an ad from the 70's where the similar 78S11 sockets were twenty five cents each.
Note that unlike the I/O ports, the plug is situated on the chassis and socket is on the end of the cable. This is to prevent someone from inadvertently touching live power to something that shouldn't see live power. They used grey clad multi-conductor cable. I think that similar grey clad cable is still available from standard sources like mouser or digikey.
Note that some original SCELBI owners integrated their power supplies directly into the chassis, removing the need for an external box and cabling.
A picture of what I think is a production power supply is on the CHM web site. I'm guessing that SCELBI built some standard or modified Power-One supplies into this power supply chassis, but so far, my efforts to get that confirmed by the CHM or SCELBI employees have not been successful.
http://www.computerhistory.
Someday I'd like to reproduce it.
regards,
Mike W.
FYI,
Amphenol 78S4 sockets and 86CP4 plugs were the "standard" connector used for connecting the power supply to the chassis and peripherals on the SCELBI. Current supply is limited and prices are rising. Corey tells me that Leeds Radio in New York told him that the sockets went out of production last year. The socket can be currently found at a alliedelec.com and the plug can be found at tedss.com (tedss also has a ebay store). Cost is approximately $9.00 each. Last year the sockets were under $5 and I saw an ad from the 70's where the similar 78S11 sockets were twenty five cents each.
Note that unlike the I/O ports, the plug is situated on the chassis and socket is on the end of the cable. This is to prevent someone from inadvertently touching live power to something that shouldn't see live power. They used grey clad multi-conductor cable. I think that similar grey clad cable is still available from standard sources like mouser or digikey.
Note that some original SCELBI owners integrated their power supplies directly into the chassis, removing the need for an external box and cabling.
A picture of what I think is a production power supply is on the CHM web site. I'm guessing that SCELBI built some standard or modified Power-One supplies into this power supply chassis, but so far, my efforts to get that confirmed by the CHM or SCELBI employees have not been successful.
http://www.computerhistory.
Someday I'd like to reproduce it.
regards,
Mike W.
Sunday, May 19, 2013
Thursday, April 25, 2013
Sunday, April 14, 2013
Wednesday, April 10, 2013
Completed Backplane Card
704 solder points and a few hours later. I took a 15 minute break to sit with my x GF, other than that it was some seriously dizzy soldering, for a few hours. I will give the backplane the red-pencil check tomorrow under a magnifying glass to make sure I didn't miss any points.
BTW, I am using 63/37 Rosin Core solder - .020 This is the same that I used on all 3 Apple-1 clones.
This stuff is poisonous, (lead) so make sure you have a window open or a fan or something for adequate ventilation. I prefer it because it's easier to work with than the "safe" stuff.... but that's up to you.
As you can see below, I've inserted the Front Card into the BackPlane Card. Nice fit, but as Mike Willegal mentioned, there is some play, so you will probably need PCB Guides (I am shopping for mine now, or may make my own).
BTW, I am using 63/37 Rosin Core solder - .020 This is the same that I used on all 3 Apple-1 clones.
This stuff is poisonous, (lead) so make sure you have a window open or a fan or something for adequate ventilation. I prefer it because it's easier to work with than the "safe" stuff.... but that's up to you.
As you can see below, I've inserted the Front Card into the BackPlane Card. Nice fit, but as Mike Willegal mentioned, there is some play, so you will probably need PCB Guides (I am shopping for mine now, or may make my own).
Front Panel
Because I haven't soldered in about 2 years, I decided the backplane might need to be the second component to work on. So I went with the Front Panel sockets. I tinned the tip of my iron for the first time in ages, cleaned the PCB with rubbing alcohol, and went to work.
I was out in the Bay Area back in mid Feb 2013 ... here are a few pics of the SCELBI 8B (Business) on display at the Computer History Museum in Mountain View, California.
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