<p><strong>Picture 1</strong><br />
<img src="https://hackerpublicradio.org/eps/hpr4222/hpr4222/1.jpeg"
alt="Shows the EPROM (Erasable Programmable Read Only Memory) fitted with a label marked JAF7. EPROM&#39;s can be erased by removing the sticker and exposing the device to strong ultraviolet light. I incorrectly refer to it as a PROM (Programmable Read Only Memory. Below it is the old leaking PLL backup battery." /><br />
Shows the EPROM (Erasable Programmable Read Only Memory) fitted with a
label marked JAF7. EPROM's can be erased by removing the sticker and
exposing the device to strong ultraviolet light. I incorrectly refer to
it as a PROM (Programmable Read Only Memory. Below it is the old leaking
PLL backup battery.</p>
<p><a href="https://en.wikipedia.org/wiki/EPROM">Wikipedia article about
EPROM&#x2019;s (Erasable Programmable Read Only Memory)</a></p>
<p><a
href="https://hinonline.com/p/fluke-77-iv-multimeter-digital-multimeter-cat-iv-600v_fluke-77/">Link
/ example of a Fluke 77 DMM (Digital Multi Meter)</a> I mention that I
used it to check the battery voltage of the original PLL backup battery
which I think was manufactured around 1984. I was very surprised to find
that the battery which is likely 40 years old had a battery voltage of
3.2V which is a healthy voltage. The battery still needed changed due to
liquid (probably acid) which can be seen in picture 1 being present on
the top surface of the battery.</p>
<p><strong>Picture 2</strong><br />
<img src="https://hackerpublicradio.org/eps/hpr4222/hpr4222/2.jpeg"
alt="Shows me extending the new battery terminal using the leg of a 1.8 kilo ohm resistor. Note that the resistor leg is shiny because this time I scraped away the surface oxidation using pliers prior to soldering it in place. This improves the final solder joint." /><br />
Shows me extending the new battery terminal using the leg of a 1.8 kilo
ohm resistor. Note that the resistor leg is shiny because this time I
scraped away the surface oxidation using pliers prior to soldering it in
place. This improves the final solder joint.</p>
<p><a href="https://www.govdeals.com/asset/3596/7126">I mention I have
an EC2000 Weller Electronically controlled soldering station. Here is a
link to an example I found</a></p>
