DEC PDP 11 RK05 DEC custom (?) bootstrap board

I have what I believe to be two DEC RK05 bootstrap boards each with a ROM labeled 802350 A. UNIBUS. The plastic handle tabs are Digital Equipm.'s but it could be an OEM as there is nothing printed on them. On the board is printed on what would be the bottom front side R-K ABBR BOOT P.C. BOARD 60

Re: DEC PDP 11 RK05 DEC custom (?) bootstrap board

Most likely not DEC. The blank handle says as much, and the part numbers you gave are not in the DEC standard format. Also, I would not expect "R-K" in a DEC references to the RK05/RK11. paul > On Aug 29, 2018, at 2:28 PM, Bill Degnan via cctech > wrote: > > I have what I believe t

Re: DEC PDP 11 RK05 DEC custom (?) bootstrap board

Hi Bill, They don't sound like DEC numbers. Maybe Plessey? Thanks, Paul On Wed, Aug 29, 2018 at 1:28 PM Bill Degnan via cctech < cct...@classiccmp.org> wrote: > I have what I believe to be two DEC RK05 bootstrap boards each with a ROM > labeled 802350 A. UNIBUS. The plastic handle tabs are Di

A New Zealand-based early '80s microcomputer retailer talks about his experience

This won't be of interest to everyone, but if you want to hear what it was like to open and run a microcomputer store in New Zealand back in the early 1980s, it's captured here. https://www.classic-computers.org.nz/blog/2018-08-23-viscount-electronics.htm Terry (Tez)

Re: Color of Leaky Electrolyic Caps?

- Original Message - From: "Marvin Johnston via cctalk" To: "ClassicCmp" Sent: Wednesday, August 29, 2018 6:33 PM Subject: Color of Leaky Electrolyic Caps? >I was just checking out the leaky capacitors on the model 100 > motherboard, and they are all colored black. And ditto for the

Re: Color of Leaky Electrolyic Caps?

Black is a common wrap color for electrolytics, wouldn't be surprised if the majority are black wrapper. Plenty of leaky brown wrappers, too. And yes, blue :) Thanks, Jonathan On Wed, Aug 29, 2018 at 6:33 PM Marvin Johnston via cctalk < cctalk@classiccmp.org> wrote: > I was just checking out the

Color of Leaky Electrolyic Caps?

I was just checking out the leaky capacitors on the model 100 motherboard, and they are all colored black. And ditto for the HX-20. The ones that are both light and dark blue look to be fine (no leakage.) So am I just seeing an anomaly, or is this the experience of most people here?

Re: Epson HX-20, TRS-80 Model 100 Capacitor Kits

Well, I rarely use vinegar and much prefer diluted Muriatic Acid (swimming pool acid to adjust pH), and have done that in this case. FWIW, a hydrochloric acid based solution is what what many PCB shops used to clean the tin-lead plating (used as an etch resist) before it got heated and alloyed

Re: Epson HX-20, TRS-80 Model 100 Capacitor Kits

Oh Marvin, you're on your right to disagree :) Thats why we're here, to discuss, learn and teach. The salt...well, the first step of reparing a leaked board is to wash it in vinegar to neutralize salts/alkali and wash again with water+apropriate detergent. If you haven't done this, you're not doin

Re: Epson HX-20, TRS-80 Model 100 Capacitor Kits

Hi Alexandre, I very much disagree with your NEVER use a drill comment and add more solder w/heat for several reasons, valid at least for someone who knows what they are doing. First, the little information I could find on the solder corrosion caused by leaky electrolytic capacitors suggeste