Unusual 512K Analogue Board Upgrade Kit

[Mac128]

This eBay auction was so unusual I simply had to post it.

It seems to be the Larry Pina Book, with an original 512K Apple analogue board replacement along with a "Soft Solutions" upgrade kit, including all the higher grade, heavy duty replacement parts Pina Recommends.

Was this Soft Solutions a company that sought to capitalize on Pina's upgrade instructions by packaging all the parts necessary to upgrade the 512K analogue boards?

What's interesting about this kit now, is that it's not just a ready-to-go-off-the-shelf replacement but a do-it-yourself kit that gives the hobbiest or newbie the hands on experience and satisfaction of doing the work themselves and getting to know their Mac in the process.

 

[JDW]

Thank you for this link, Mac128.

I found the most interesting aspect to be in the auction's Schematic of the Vertical Sweep Section. For sake of comparison, have a look at the schematic in Figure 3 on page 5 of Tom Lee's Classic Mac Tech Info pdf. Specifically, note where the Emitter of Q4 connects, as well as the (-) side of CR7. On Tom Lee's schematic, the (-) side of CR7 is tied to +12v along with the Emitter of Q4. But in the schematic presented in the auction (created by Soft Solutions, I am assuming), the Emitter of Q4 goes to +12v but the (-) side of CR7 goes to Ground.

 

[trag]

Was this Soft Solutions a company that sought to capitalize on Pina's upgrade instructions by packaging all the parts necessary to upgrade the 512K analogue boards?

Them and Pre-Owned Electronics (?) offered complete kits of the parts that Pina recommended replacing/upgrading.

Pre-Owned sold the kit (no book though) for $50 each, but, if one purchased 5 or more, the price was $25 each. So if you were going to get 3 you might as well get 5. I bought five, once.

Given the disappearance of all sources of flyback transformers, I wish I had bought more, but I didn't have very much money back then (like add up your grocery cart to make sure it doesn't overdraw the bank account).

 

[JDW]

I linked to version 1.1 of Tom's Lee's PDF by mistake in my previous post above.

Here is the link to version 2.0. In the version 2.0 PDF, the discrepancy in the schematic appears in Figure 11 on page 18. And once again, here is the auction schematic. When comparing the two schematics, note the area of Q4 (2N4401), located toward the bottom of the schematics.

Any thoughts on this, Tom?

 

[tomlee59]

I linked to version 1.1 of Tom's Lee's PDF by mistake in my previous post above.
Here is the link to version 2.0. In the version 2.0 PDF, the discrepancy in the schematic appears in Figure 11 on page 18. And once again, here is the auction schematic. When comparing the two schematics, note the area of Q4 (2N4401), located toward the bottom of the schematics.

Any thoughts on this, Tom?

Thanks for comparing the two so carefully, JDW. It looks as if the difference is in our labeling of CR7 and CR8. Other than that, the schematics seem to agree (at least in that neighborhood of circuitry). I wouldn't be at all surprised if I transposed those labels by mistake.