Getting the Ricketts Apple-1 running...

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Joined: Oct 9 2011
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Well now that the cat is out of the bag and the Apple-1 from the book, "The First Apple" by Bob Luther is up for auction at Christies. I was helping the owner prep this board at the end of September.

http://www.christies.com/about/press-center/releases/pressrelease.aspx?pressreleaseid=7561

Now this board isn't the same quality as the board that sold at Bonhamns, but the story and documentation makes up for that... So it really depends on the type of collector you are Wink
This is not a perfect board but has tons of related documentation, where the Bonhamns was a perfect board, but had little original documentation directly Apple-1 related.

This was not a "byte shop board", but an early Apple-1 sold directly by Steve Jobs, most likely without the knowledge of Woz, it seems he has done that before. If you have read Bob's book, you'd know how it moved through different hands and I can confirm the suspected use as a video "announcement" system for what must have been an automobile repair place.

So first the repair story to bring the system back up.

First step was to figure out all the rework and wiring... here is an example

Looking how it was all wired up and the wiring in the case, it appears that an eprom was wired up to drive the 6820 PIA with characters. The keyboard connector's reset and clear screen were wired up in a strange way, but understandable way, using diodes to use a single toggle switch to clear and reset the system and also setup to allow a programatic clear screen. It appears from the circuit that they used an external selection system to choose the string that was "typed" into the Apple-1 terminal section. The PROMs were not programmed with the Apple monitor, but appear to have been involved with driving the video "announcement" system. There was also a modification to the video circuity to increase the signal strength.

All of this circuitry had to be carefully removed since it's not like it was a printer adapter, it would inhibit the Apple-1 from operating as it was originally sold by Jobs.

Upon further investigation this unit did have a cassette adapter at some point because the correct pads were "tinned", but the line had been removed. and an original ACI was not included. The RAM was also not correct for the system and I sourced the correct original date correct RAM.

Before powering up, I went through my normal procedures for all the caps.

There were a few bad chips also, which I sourced with correct components.

I did have to make the power supply "safe" and also do some work on the datanetics keyboard, which was included when Bob acquired the board but was wired up to work with an Altair PIA. So I rewired it for the Apple-1 since it would have been the exact type of keyboard used in the day.

I also provided a spare modified Apple II plus keyboard and a replica ACI so that the system could be comfortably operated in the future as Datanetics keyboards really need to be used continually or they will need "work", so this was a good compromise to make sure when ever the system is fired up, it works perfectly.

And so the system is now fully operational.

Here is the rickets board with an original ACI "borrowed" from another machine.

Here is the rickets board as I was working on it using one of my keyboards

Here is the rickets board operating with the included spare keyboard and replica ACI.

And before you ask, I don't have any close up pics of the checks written to Steve Jobs other than what's being provided by Christies.

Cheers,
Corey

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transwarp II guy's picture
Joined: Mar 7 2013
Posts: 465
Re: Getting the Ricketts Apple-1 running...

I'm subscribing to this thread. Your adventures with Apple 1's are always nice to read.

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Joined: Aug 24 2013
Posts: 45
Re: Getting the Ricketts Apple-1 running...

Corey,

Thank you for posting this, it answers a number of questions that I had regarding this system after looking at the pictures. It also explains why Christie's has posed the various pieces of the collection in their images.

Were you able to obtain dumps of the PROM chips and EPROM ?

A schematic of the alterations would also be very informative, both from an educational and historical preservation perspective.

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Joined: Oct 9 2011
Posts: 1045
Re: Getting the Ricketts Apple-1 running...

Christopher,

I did take a dump of the proms and stuff. I will try to document/create a schematic when I get a change from the pictures. It may be a while as I'm in the middle of another project, but for historical reasons, you are right it should be documented.

Cheers,
Corey

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Joined: Oct 4 2014
Posts: 64
Re: Getting the Ricketts Apple-1 running...

Corey,

These old Apple I's always seem to have defective chips.
Which chips usually fail in these computers ?

Joined: May 24 2013
Posts: 3
Re: Getting the Ricketts Apple-1 running...

Have there been any working Apple-1 computers that have all their original chips?

The Henry Ford just missed with one failed/replaced chip and haven't heard how many failed/replaced chips for the Ricketts.

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Posts: 1045
Re: Getting the Ricketts Apple-1 running...

Well the Fairchild 7451 is the most common one I have seen. No issues yet with a signetics board. However the bonhamns board also needed to have some chips removed and the legs straitened and then reinserted. They all seem to need some of that tender loving care because the TI sockets are terrible. I've only ever had to replace/repair the most 3 sockets on a single board, just not on the ricketts or bonhamns ones, the pin straitening worked.

The next weak point is the 6820 and the ram. The keyboard is directly plugged into the 6820 without a buffer so it is easily damaged. The ceramic 6502 are also static sensitive.

We are only taking chips here. There are other descrete components that are of concern.

Cheers,
Corey

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Joined: Oct 4 2014
Posts: 64
Re: Getting the Ricketts Apple-1 running...

Corey,

Thanks for your insight.

I would have suspected that the big electrolytic capacitors (5300 and 2400 uF)
would have dried up after 40 years and also caused problems.

DRAMs I found to be static sensitive.
It is worth spending five dollars for a wrist grounding strap and using it during all chip swaps.

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Joined: Oct 9 2011
Posts: 1045
Re: Getting the Ricketts Apple-1 running...

I have found that I don't always use a wrist strap. Depends on what I am doing, the humidity in the room and if I have to physically move. I do always touch metal and am very careful what materials my clothes are made of and what are on my feet.

That being said. I will almost always use a wrist strap as the fall and winter arrives as the chance for static discharge goes up.

Basically you need to be smart. A wrist strap could get in the way and break something sensitive. One thing to be aware of is that most people don't ground the wrist strap correctly. I also use a grounded anti static mat regardless of time of year or what I am wearing.

The worst thing you can do is wear those white cotton gloves that some of the auction houses use. That is asking for trouble. If I have to keep finger grease and oil off, I used anti static disposable rubber gloves (not really sure if they are rubber or something else)

Cheers,
Corey

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Joined: Aug 24 2013
Posts: 45
Re: Getting the Ricketts Apple-1 running...

I follow similar practices to Corey.

My really sensitive and/or valuable systems tend to get packed away for the dry months. If I bring them out for a special reason, then they get extra careful treatment.

I watch carefully what clothing I wear and how much movement I make (I have a large collection of nice sweaters from gifts that I rarely wear for this reason.) I pay close attention to what I was doing, where I was, and what I was wearing when I sense any type of static buildup on myself. I use that as a reference to what conditions are when working with systems and do what I can to avoid them.

I have been borrowing one of the lab benches at work with a full sized anti-static mat when doing work on systems. I find it not only better for the parts, but a whole lot easier than working in my small apartment's living room.

A EE mentor of mine made it a point to always touch my wrist before passing me a part until I had all pins touching my hand. I still practice that technique by touching the mat before picking up a part. After I move with it, I then will touch the mat again before setting it down or inserting it into a system.

Even working with modern systems I note what parts of the system have a solid connection to ground and use that to ensure that I'm properly grounded before pulling or inserting parts.

The dryer the time of year, the more sensitive the parts, the more techniques I use to eliminate static.

Overall, this has worked well for me.

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Joined: Jun 5 2008
Posts: 380
Re: Getting the Ricketts Apple-1 running...

Regarding the big blue Sprague Capacitors, I'm unaware of any failures of those in any Apple 1. Heat is the major danger to those, and with most units lacking an enclosure, I suppose they aren't getting subjected to the heat or heat cycles that one located in an enclosure with a power supply might be subjected to.

With all the constant noise about electrolytic capacitors going bad, over many years of fooling with electronics gadgets, I've only had to replace one, and that was in a relatively new cassette deck. go figure...

regards,
Mike W.

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Joined: Oct 9 2011
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Re: Getting the Ricketts Apple-1 running...

Mike,

I know of a few Apple-1 that have had the blue caps replaced, including a board that had some damage from it. Typically big caps do four things, they turn into a conductor (bad on a system like the apple-1 without a crowbar circuit), they add noise which causes things not to work, they leak chemicals or they go boom.

I have seen other systems with 39D capacitors go boom and take out a section of the board. I have yet to see Apple-1 systems have a leaking capacitor, but I have seen the case where the ESR doesn't come to spec, but are not fully conductive, and the board won't work right with the current 39D caps and they need to be changed. The other capacitors of concern are the smaller blue ones experiencing the same issues.

Obviously you can try reforming caps that aren't up to spec on ESR, but it doesn't always work.

Cheers,
Corey

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Posts: 380
Re: Getting the Ricketts Apple-1 running...

Hi Corey,

I don't mean to start a debate, just offering my opinion, and your mileage with old components of any type WILL definitely vary. Certainly, I've seen my share of bad batches of components of various types. It pays to be cautious, when operating any equipment with old components. It's not a good idea to operate reproductions, let alone the old original systems without someone watching over it.

There are a couple of Apple 1s that had the Sprague caps removed, for unknown reasons, which doesn't count as a capacitor failure, at least in my mind. That you know of others that had the caps replaced, one with damage in the general area is good to know and it certainly could be caused by Sprague capacitor or another kind of failure.

That aside, in general these Sprague caps have survived the ravages of time quite well in the environment where most Apple 1's were operated. Quite a number of Apple 1s have been powered up over the last few years, with no issues with the caps. Also, when I was doing kits, I bought a fairly large batch of NOS early 80's Sprague caps, and those were all fine. I did take some precautions when I first went to use them. After the initial experience went well, I decided in the end, that extra caution with that batch wasn't necessary.

I'm thinking about the 74151 (I believe you meant 151, not 51) failures that you reported. I think I have a possible reason for it. The 74151's contain the page decode circuitry, which was often used as the address decode for custom hacks and add on's for the Apple 1. Should someone mess up making such a hack, they could easily fry the 74151 or kill one of the 74151 output lines. Might be worth investigating to see if the units you found with bad 74151s had hacks applied to them at one time or another.

regards,
Mike W.

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Re: Getting the Ricketts Apple-1 running...

I have restored electronics from the 1920's to the present and I guarantee you that all the original electrolytic capacitors on the Apple I's will fail within the next 20 years.
All other components can last indefinitely.

Of the hundreds of electronic devices I have repaired from the vacuum tube era, I have seen almost all capacitors prior to the 1965-1970 period with "wet" dielectrics (electrolytic and paper) fail.
Very few operational vintage electronic devices have their original capacitors in place.
Out of a pile of NOS electrolytic capacitors from 1940's and 1950's I bought once, not one was useable despite them have been stored in a basement for most of their lifetime.
Like Mike mentioned previously, a hot environment accelerates the progression towards failure.
Only capacitors with a dry dielectric like ceramic and mica will last more than 50 years.

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Re: Getting the Ricketts Apple-1 running...

So Mike W. and I spoke yesterday. The commonly failed chip is a 7451 in the 7450 marked socket. It is connected to the keyboard socket, so that would explain why it could be fried. Since we know many Apple-1 also have the 6820 replaced most likely for a similar reason since it also is directly connected to the keyboard also.

Cheers,
Corey