Page 7 of 13
Re: Internal 512k expansion?
Posted: Sat Feb 19, 2011 7:12 am
by deathshadow60
I'm more referring to putting these:
http://www.allelectronics.com/make-a-st ... 40//1.html
on a board one row off from a socket and then soldering across rows, or you put them next to female row headers like:
http://www.allelectronics.com/make-a-st ... LE//1.html
reminds me, need to pick up a 31x2 pin socket and a 62 pin edge-card connector to make a tandy plus to ISA adapter.
Oh, and you could always use wire-wrap sockets, they have the longer pins making doing pass-through a snap.
http://www.sparkfun.com/products/8118
-- edit -- give you some links where they are NOT out of stock
http://www.king-cart.com/cgi-bin/cart.c ... me=HWS3089
http://parts.digikey.com/1/parts/298413 ... 01000.html
Re: Internal 512k expansion?
Posted: Sat Feb 19, 2011 9:39 am
by jmetal88
I already have a 40-pin wire wrap DIP socket on hand. The pins are too thick to seat in the PCjr's CPU socket.

Re: Internal 512k expansion?
Posted: Sat Feb 19, 2011 2:18 pm
by jmetal88
Well, I started wiring up a perfboard prototype for one of my designs, today. It'll probably be a few weeks before I'm finished with it, and then I'll have to figure out how I want to go about seating the board in the CPU socket. I'm hoping it'll work out well, though.

Re: Internal 512k expansion?
Posted: Sat Feb 19, 2011 7:55 pm
by deathshadow60
jmetal88 wrote:I already have a 40-pin wire wrap DIP socket on hand. The pins are too thick to seat in the PCjr's CPU socket.

wet grind them down thinner with a dremel or rotary sander with a very fine grit. You might even consider doing it by hand with a decent sanding block.
... and trust me, don't try to do it dry, static's a *****... and only do one side for thinning them, that way like teeth they'll corrode on one side only. (you might consider tinning them after sanding)
Unless you got lucky and got solids instead of plated.
Re: Internal 512k expansion?
Posted: Sat Feb 19, 2011 10:49 pm
by jmetal88
deathshadow60 wrote:jmetal88 wrote:I already have a 40-pin wire wrap DIP socket on hand. The pins are too thick to seat in the PCjr's CPU socket.

wet grind them down thinner with a dremel or rotary sander with a very fine grit. You might even consider doing it by hand with a decent sanding block.
... and trust me, don't try to do it dry, static's a *****... and only do one side for thinning them, that way like teeth they'll corrode on one side only. (you might consider tinning them after sanding)
Unless you got lucky and got solids instead of plated.
I suppose I could try a sanding block. I don't own a dremel or a rotary sander, though. Hmm.
Re: Internal 512k expansion?
Posted: Sun Feb 20, 2011 11:03 am
by jmetal88
I think this sandpaper thing is gonna take WAY too long.
I'll have to think of something else.
Re: Internal 512k expansion?
Posted: Sun Feb 20, 2011 3:19 pm
by Brutman
I hate to ask the obvious, but have you browsed the catalog at a place like DigiKey? I've got one of their paper catalogs here, and it's several thousand pages long. All of it is available on the web too.
If they don't have it, it's either not made in the last decade or it never existed.
Mike
Re: Internal 512k expansion?
Posted: Sun Feb 20, 2011 3:26 pm
by jmetal88
Oh yeah, I always check Digikey first. I already posted a link to the only thing I could find that I thought might work.
Re: Internal 512k expansion?
Posted: Sun Feb 20, 2011 4:14 pm
by Brutman
Argh - I hate it when I do that! Ignore me ...
BTW, have you considered asking over at VC Forum? They have a few thousand more eyeballs, and some of them are hardware literate.
Re: Internal 512k expansion?
Posted: Fri Feb 25, 2011 3:21 pm
by jmetal88
Alright, I found a way to work with the parts I have on hand. I stacked a 40-pin socket from Radio Shack on the PCjr's CPU socket, then I was able to file down the pins on my wire-wrap socket until it fit in the Radio Shack socket (which required much less filing than the PCjr's CPU socket would have). After cutting the pins on the wire-wrap socket to an appropriate length, the board assembly fits neatly underneath the floppy drive. Now I just need to get the parts wired together so I can test out this setup.