Yet another apple 1 build

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Yet another apple 1 build

I finally build up the courage to start my build, having acquired all of the parts, watched way too many videos, and read / reread all of the available guides.

 

My build is using:

  • Uncle Bernie's parts kit, and his ACI gen2.
  • Newton PCB
  • Newton keyboard 
  • P-lab jukebox
  • Misc parts from digikey.com, anchor electronics, eBay,  etc.
  • Super high quality copies of the original manuals (incredible! )
  • Eventually some kind of case and or display mounting.   TBD 

 

A huge thanks to this forum and all of the enthusiasts here and above who made this possible.

 

I'm going slow because the build (for me) is a ton of fun.  I build as many retro kits as I can get my hands on since I'm an old heathkit fan.

 

I'll post my progress as I go, just a few components soldered down now.  I test everything as I go, which usually improves my success rate.

 

 

 

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Hi Mrthreeplates!
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Hi Mrthreeplates!

You have very cool kit, good luck building it!

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Great!

Good luck with your build!

Keep us posted! :-)

 

Best,

Claudio - P-LAB

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Sockets and some of the caps installed

I made a couple of stupid mistakes soldering, despite being super careful.

 

Thankfully I have a vacuum desoldering tool.  It made quick work of the repairs without damage to the board.  I am no expert, and having good tools feels like cheating!

 

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Next step, check out the

Next step, check out the power rails and do some cleaning. 

 

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Power supply built (at least

Power supply built (at least temporarily), power cable built, and all rails are good!

 

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All built... sort of...  I

All built... sort of...  I skipped a step or two in hopes I'd get lucky.  In fact, a whole lot is working great and I'm super pleased.  It boots, runs the ram test in prom, keyboard works (and looks great).

 

Unfortunately,  I get bit errors and the video is all twitchy (no surprise I'm sure).  I tried two panel TVs, and one doesn't work at all.  Sadly I don't have a crt.  So, I probably need to build Uncle Bernie's video fix.

 

In the meantime I will debug the ram errors, but first I'll do the reliability mods (as I should have in the first place!).  P-labs sd card storage has a ram bank replacement capability which I can play with.   I also have a retro chip tester.  So, lots of things for me to do and try.

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Uncle Bernie's reliability

Uncle Bernie's reliability mods fully installed.   My dram errors didn't go away until I installed the 390 ohm pull-ups on the dram address lines.  Unfortunately my video is still not displaying properly on my lcd panel, but I mostly expected that.  I have parts on order to implement Uncle Bernie's video fix, so making good progress! 

 

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Added Uncle Bernie's video

Added Uncle Bernie's video fix and I now have a usable and stable picture.  I'm playing with some of the component values to see what gives me the best picture on my two monitors. 

 

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Before finishing up the video

Before finishing up the video fix, I thought I should get the clock frequency more on target.  Once I replaced c4 (10 nF) with 12 pF, my dot clock is much closer (see my post on the crystal thread).

 

I then finished installing Uncle Bernie's video fixes, and am very pleased with the results (see the other thread). This was some tricky/challenging soldering for me!

 

 

While I was at it, I checked the pulse widths out of the 74123, and they look fine.  I was a little mislead by the 480ns pulse as I  initially was looking at the negative cycle.   Looking at the schematic, it seems the positive pulse is used?  Fortunately,  it is within 5%.  It is odd how the duty cycle is nearly 50%.

 

 

Next up is probably an extended burn in / stability test / cleaning. 

 

 

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After running the memory

After running the memory tests for a while, I got impatient and wanted to play.  I plugged in P-lab's microSD storage card and started to mess around.   I know I need to build my ACI, but I couldn't wait.  The storage card made it super easy to load all kinds of programs.   Of course I had to run the apple demo ascii art to show it off!

 

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