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Need Caps Lock keycap for Apple IIc (ALPS Amber keyboard)
Grimm1966 replied to WxAxNxDxExRxExR's topic in Apple II Computers
You might try these guys, I was able to get a replacement switch and the correct ESC keycap from them to fix my Apple IIe. http://www.ebluejay.com/store/Apple2OnlineStore Jason -
Continuing on with the frame repairs... This fist picture is of the stripped hole drilled out with the # 8 drill. You can see that there is still some remains of the mark that the screw shoulder left. This is good so hopefully there will be enough of the frame left for the shoulder to land on. Next picture is me holding the bushing up to the frame to check it's fit. Notice that the nub on the bushing doesn't go all the way through the hole so the screw will sit directly on the frame and be a lot more secure. Next is the bushings test fit and it looks good so far. The shoulder of the screw has a good seat on the frame so it should work well. Here is the picture of the other side with the bushing in place. I noticed that if it had been a little bit larger in diameter, it would have interfered with the other holes for the detente/lock mechanism. Also I could have made it a bit thinner, although that would have made it more difficult to use a wrench on it. Once I get the CRT installed in the frame I will have a better idea if it's too thick or not. I can always put it back on the lathe and take some off. Next I need to get some rust converter for the rusty spots (I detected some more rusty spots on some of the frame edges). Does anyone have an opinion on rust converter, I used some about 25 years ago and liked it. Is the conventional wisdom say that it's still good or have opinions changed over the years?
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Now it's time to look at the frame to see what is wrong with it and get it fixed up. The stripped screw hole is the main issue, but there are other ones too. It's really difficult to get a good picture but here are closeups of both of the holes. The first image is the stripped hole. You can see how smooth it is as the threads have been sheared off. And also notice the heavy mark around the hole that was probably caused by the shoulder of the screw. There was a lot of pressure on this to basically rip the screw out. This next image is of the hole on the other side of the frame. This one you can still see the screw threads are intact so it doesn't need a bushing. ' Although there is an issue with this side as well. This next image shows how the frame has been pulled so hard that it bent the frame outwards, just not hard enough to strip the threads. I'm going to attempt to hammer it back in place, it should only take a couple of well placed taps. The last issue is a spot of rust that is located just right below the CRT. At first I was thinking that this might have been caused by a leaky capacitor on one of the CRT PCBs. But when I looked at the underside of the CRT there is another rust spot just right below the CRT screen front. Maybe this was caused by some kind of condensation from the CRT tube, or maybe just from cleaner being used to clean the monitor glass? Here is the rust spot on the CRT... Also I'm going to give it a good clean.
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Thank you, it's been an adventure for sure. Still a lot more to do, but I'm seeing the light at the end of the tunnel (I think).
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This last step is the other operation I am really worried about, that is cutting off the part. In this case you have a cutting blade that is in the tool holder and you are cutting into the part to separate it from the bar. I set up the cutting blade as parallel as I could and hoped for the best. It worked just fine, the cutting blade only started to whine at the very end of the cut. Here I set up a catch for the part so it didn't go flying off when the cut finished. Here is the finished bushing after some edge clean-up...
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Continuing on, the next step is to tap the hole and put the threads in. Here I have the tap, in a tap holder, and a spring-loaded tap center in the lathe tail stock. Now lets check the fit of the screw and see if I choose the correct thread size. Yay, it works. I forgot to take a picture of making the nub, but it worked well too.
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Making the bushing... I'm not sure anyone will be interested in this part, but I will include it for completeness. First I need to mount the brass bar to the lathe, this is where the first issue comes up. I have a Grizzly mini-lathe that I bought in 2009 and I have done a lot of modifications to it so it works better. As much as some people poo-poo these lathes, this one has been really good and I have even made steam engines, etc. with it. As you can see from the image, the 5/8" bar does not fit into the bore of the chuck and sticks out a lot. For machining you don't want the part you are working on to stick out more than how much is being held by the chuck. Less is better and much more stable. The only larger chuck I have is a four-jaw which would be really hard to get the hex shaped bar centered in. And because all of the work will be on the end, I can't support the bar with a center or some other way. I decided to see how the next step would go, that would be to face the end of the bar. If I got a lot of chatter or it looked dangerous I would have to go some other route. As luck would have it (probably because I'm working in brass) the facing operation went really well. So I continued on.. The next step it to start the hole with a center drill. In this case a really itty-bitty one. The next step is to drill the hole to the correct size to accept the tap for the screw threads.
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Now the plan for the stripped screw for the handle. Here is a quick sketch I did of the part I need to make for the bushing replacement. I have a short length of 5/8" hex brass bar so I thought I would use it instead of a round bar. In this way I can just use a wrench to hold the bushing in place as I screw the handle on. I was thinking of gluing the bushing on, but I'm worried that the forces involved will be too great to have any kind of glue hold. The A and B measurements for the bushing are the most important ones here. A is the thickness of the bushing which should be able to take the entire length of the screw so it can have as strong as a hold as it can. The B measurement is the diameter of the nub that helps to register the bushing to the hole in the frame. I will make it shorter than the thickness of the frame (which is about 1.3mm thick) so when the handle is screwed on, the shoulder of the screw makes full contact with the frame. The outside diameter of the nub should fit the size of the hole that I'm drilling out. In this case I choose a Imperial numbered drill (#8) which is .199".
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Now that I have the frame of the SX-64 stripped down as far as I want to go, I thought I would show the differences between the earlier model and this later one. Here are the images of the frames... The top image is my SX-64 and the bottom image is an earlier one. The main difference is in how the floppy drive and the "glove box" is attached. For the earlier versions you have to remove the CRT and the main board to get at the screws to remove them. On the later versions, like I posted before, you need to remove the four screws from the top and then lift out both parts. The other thing they did was to change how the cartridge port cable was routed. On the earlier version you can see that they had a gromit applied to the rectangular hole in the cartridge port post. That is where you fish the cable through for the port and they wanted to protect it as much as they could. On mine there is no gromit, but instead the top of the post has been lengthened and turned down to have a rounded top. Instead of fishing the cable through the post, you route the cable under the cartridge port PCB but on top of the rounded post top. I think they did this to keep the cable away from the floppy drive and so it will not get caught up in the moving parts. The other difference is that the "glove box" has separate brackets that attach to it, whereas mine has separate brackets attached to the floppy disk.
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I did find this on the PI1541, but I don't know if this is good enough, or if there are commands that the C64OS needs that the PI1541 doesn't implement? https://github.com/pi1541/Pi1541/blob/master/docs/IEC Commands.md
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I didn't see this in the manual, but can you use a PI1541 and/or an original 1541 with the OS? Thanks,
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I thought I would add that I have hooked up all of the control lines to the Ultra-Reset. This will control the floppy drive reset, the computer reset, the drive ID, and switch the Jiffy-Dos roms. All of this is accessed through the floppy reset switch on the front panel.
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I'm finally able to get back to the SX-64. I have the Ultra-Reset installed and working. Next is making the bushing for the stripped handle screw. I will need to get my lathe up to speed to start that.
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Yes, capacitors were the culprit for my Coco I, once I replaced them the video noise reduced considerably. With RF it will never go away, but you can get it to be usable. Best solution is to do a composite modification. About the disk controller, I don't know, I don't have one and I'm not too familiar with these computers.