On the use of early-mid 1970s 4k x 1 DRAMs in the Apple-1

Here is a report about the use of early-mid 1970s 4k x 1 DRAMs in the Apple-1.

Most of us are using later 4k x 1 DRAMs produce towards the end of the 1970s or later, such as the ones I furnished with my famous kits (now sold out). Typical examples are:

Motorola MCM4027AC3 Date codes 7927, ...

Mostek   MK4027N-4  Date codes 7935, ...

Intersil MK4027J-3  Date codes 7948,8017 ...

It was found that the former needed all the "reliability mods" with the extra bypass capacitors and the six damping resistors, Mostek often was happy with only the damping resistors, and on some PCBs / builds, the Intersil ones needed no reliability mods at all…


ASCII Keyboard Tester PCB and Kits


nijssen has released the second version of his ASCII keyboard tester, tested with a Datanetics replica keyboard for the Apple-1 and an Apple ][ keyboard. Schematic is attached.

Kaiweets KOT936 Soldering Iron Review

I was approached by Kaiweets recently, asking if we'd consider reviewing their KOT936 Electric Soldering Station. We don't get requests like this often, and especially not for soldering irons. In 2005, Dr. Webster wrote a scathing review of the ColdHeat Classic. For years, it was a top Google search result for "ColdHeat", prompting ColdHeat and Weller representatives to register at Applefritter and post rebuttals in a long forum discussion full of ColdHeat criticisms. ColdHeat is no longer in business.

That's why I was surprised when Jane from Kaiweets wrote me, saying "I browsed your site carefully and I noticed that there're some posts about soldering and related tools. So I think it would be a perfect fit to get our product exposed there." How carefully did Jane browse Applefritter? Is she aware of our history with ColdHeat and that confident in the KOT936's abilities? I normally ignore emails like this, but I couldn't resist the opportunity to put another soldering iron in Dr. Webster's hands. I accepted, and gave Kaiweets the mailing address of our resident soldering iron torturer, Dr—"it's such a pile of junk it's unbelievable it's still on the market"—Webster. He received the iron for free. Kaiweets has had no other influence on the editorial process. Will he like the KOT936? Will he destroy another soldering iron company? Read on to find out! –Tom Owad

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