7 Nov 2023
From: Michael Zyda
zyda@mikezyda.com
1. There are many people that have made strong statements on the technologicalpossibilifies/impossibilifies they have personally discovered in the video recordings of Billy Mitchell’svarious game plays of Donkey Kong. All of these tests are looking for the sources of the anomalies on
the Billy Mitchell videotapes. Many claim to have wired their systems exactly as Billy Mitchell did but,in the end, fail to achieve the same anomalies. Here are some of my opinions on these issues.
a) When Billy is recording from the arcade machine running at 60 fps (frames per second), he plugsthat 60 fps stream into a Two Bit Converter box (the converter) and the converter outputs a 30
fps stream to a VHS VCR for recording. There is no apparent sync signal from the 60 fps device tothe converter box outpufting a 30 fps stream. The purpose of the sync signal would be to makesure there is some kind of frame alignment. Without the sync signal and frame alignment, we
actually don’t know what the converter is really doing. If we had frame alignment, we wouldexpect that two frames from the 60 fps stream would be used to create one frame in somefashion. If we don’t have perfect frame alignment, then we are going to see visual arfifacts suchas the anomalies at issue. And all of the analyses of the Billy Mitchell tapes rest on anomalies
recorded in this fashion.
b) Another issue not well addressed is that of component aging. The Nintendo Donkey Kong boards
are old and their various electronic parts are aging at diﬀerent rates. As those components near
failure, the potenfial for visual arfifacts increases. This means there is no way to compare
diﬀerent Donkey Kong boards as their component failures most likely are in diﬀerent parts. Thisincludes the power supplies that power the Donkey Kong boards. As those power supplies age,
we have no way of measuring how that aging will impact the Donkey Kong board’s operafionsand visual display. As such, there may not be any way to compare recordings from the same board
done at diﬀerent fimes. In my opinion component aging could produce the anomalies at issue.
c) Another issue brought to mind is that of copies of copies of videotapes. As videotapes are copiedand handed out to someone who then makes copies, visual arfifacts often appear as second andthird generafion and beyond copies are made. It is important to note that it is unknown how
many generafions of copies were created to arrive at the current videotapes. Another issue withrespect to this is whether the videotape heads were cleaned before the copies were made,including whether Billy Mitchell was cleaning his VCR’s heads before he recorded the Donkey
Kong play. It is my understanding that he was not. Further, it is my understanding that Billy
Mitchell recorded his tapes at long play (LP) to save on the cost of videotape. LP recordings arelower quality recordings and often record with much on tape visible noise. It is also myunderstanding that Billy Mitchell reuses videotapes without re-blacking the tapes beforehand.
With dirty record heads, this often means that previous recording informafion will bleed throughand be visible. In my opinion, this could produce the anomalies at issue.
1|Paged) The wiring of test systems also seems to have the potenfial for causing visual anomalies.
Quesfions like, “do the video carrying cables drape over or near a power supply?” and “are thecables carrying the video shielded cables or unshielded cables?” do not seem well answered.
These scenarios could also produce the anomalies at issue.
e) Component aging with respect to the Two Bit Converter is also a large issue. Recently, Neil
Hernandez obtained a Two Bit Converter from Billy Mitchell’s garage in Florida and aftempted toget it working with a Donkey Kong machine. It is my understanding that the converter had beensifting in Billy Mitchell’s un-aircondifioned garage for many years. The inifial connecfion showed
completely wrong colors so Neil decided to see if he could repair the converter. Neil’s insfincts as
an arcade game technician told him he should start with the capacitors. Neil changed out thecapacitors in the converter and as a result had an almost perfect picture output with propercolors. With replacing just the capacitors, Neil saw the “girder ﬁnger” on the monitor receiving
the output from the rebuilt converter. Neil took one sfill picture of that girder. A copy of that
picture is aftached. Neil then replaced the old resistors on the converter board. When hecompleted that replacement of the resistors, the “girder ﬁnger” was no longer present. So,component failure from the old resistors produced the “girder ﬁnger” in the converter in thiscase. Neil hypothesizes that the decaying resistors were outpufting the wrong voltage and thenew resistors ﬁxed that. In my opinion this is a reasonable hypothesis.
I asked Neil Hernandez to rebuild the converter with the old resistors to see if we could get aconsistent “girder ﬁnger” output from that converter to the connected monitor. That experiment
failed likely because the combinafion of heat from the soldering gun and the fragility of theresistors ﬁnally made them completely stop working, with the converter failing to work at all afterthat experiment.
However, Mr. Hernandez’s experiment, which I saw recordings of, depict numerous anomalies,
including diﬀerent numbers of girder ﬁngers, Mario teleporfing around the screen, barrels rollingthe wrong direcfions including uphill, pies disappearing, and the hammer not vanishing when itis dropped. These resulfing anomalies are consistent with my expert opinion that the game playon the subject video tapes, including the anomalies depicted, could be from original Donkey Kong
hardware, and that the anomalies are the result of component degradafion in the Two Bitconverter.
2. So, with all of these potenfial sources of anomalies and with all of the diﬀering wiring and test
conﬁgurafions, it seems unlikely to me that deﬁnifive answers are readily obtainable from Billy’s
recorded play sessions watched and single-framed on second and third generafion and beyond
videotape copies. The likelihood that Two Bit Converter components would fail idenfically acrossmulfiple converters so that experiments could be aftempted is unlikely and makes deﬁnifive answers
from such tests unlikely. However, it is clear that the video tapes could depict game play on original
Donkey Kong hardware despite the anomalies depicted.

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