Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Discussion of development of software for any "obsolete" computer or video game system.
lidnariq
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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by lidnariq » Fri Mar 20, 2020 5:21 pm

nintendo2600 wrote:
Fri Mar 20, 2020 5:11 pm
Anyhow, so that is most likely an 1n4148 correct? or would it be something else?
Most likely, yes. Stored energy in the inductor is going to be around 75mA→16µJ at max, so an ordinary signal diode should be fine. Although it's possible that something faster would be better...

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nintendo2600
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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Fri Mar 20, 2020 5:26 pm

lidnariq wrote:
Fri Mar 20, 2020 5:21 pm
nintendo2600 wrote:
Fri Mar 20, 2020 5:11 pm
Anyhow, so that is most likely an 1n4148 correct? or would it be something else?
Most likely, yes. Stored energy in the inductor is going to be around 75mA→16µJ at max, so an ordinary signal diode should be fine. Although it's possible that something faster would be better...
Anything you want to recomend to get? I have some on hand but will order whatever will help. Also, please check my digikey link I added about the photo sensor. I dunno if 850nm is too wide when the stock one is only at 800nm?

This one below is only 825nm but I'm not sure about the other specs yet.

https://www.digikey.ca/product-detail/e ... ND/1681144

This one below is supposed to be an equal to the MRD310, do you agree? I ask as this one is at 850nm so it can't be exact.

https://www.digikey.ca/product-detail/e ... ND/1681152

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by lidnariq » Fri Mar 20, 2020 5:51 pm

Is there another lens in the GAMEGUN? Or does it just rely on the lens in the phototransistor and shrouding of the GAMEGUN's barrel? You may want something with a narrower field of view - the original is using φ=15° half-width.

edit:----
(In contrast: BPW16N = φ=40°. BPW76A = φ=40°. BPY62 = φ=8°)

My hunch is that TV phosphors don't emit any IR, and what you care about is how efficiently the phototransistor will convert what light they do emit into current. If wikipedia's spectrum here can be trusted, a modern-ish TV's use of P22R phosphor emits a lot of light at 700nm, and a lot a ≈620-630nm, and otherwise not much. So something like the original MRD310 will see 700nm light at 75% as capably as 800nm light (and 620-630 approximately 55% as efficiently) while the BPY62 will be 70% and ≈60% as capably as 830nm light)
----

I don't know how critical any of the properties here are. The original phototransistor had a rather low dark current and rather fast on/off time. But the dark current should just change the DC level coming out, and that should be removed by the capacitor between the phototransistor and the 2N3904.

In contrast, DigiKey doesn't even let you filter by turn on/off time, and Mouser implies it's rather difficult to get phototransistors that are anywhere near as fast as the original MRD310.

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nintendo2600
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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Fri Mar 20, 2020 11:50 pm

lidnariq wrote:
Fri Mar 20, 2020 5:51 pm

In contrast, DigiKey doesn't even let you filter by turn on/off time, and Mouser implies it's rather difficult to get phototransistors that are anywhere near as fast as the original MRD310.
I came across this info while googling around from a seller with lots of parts:

Silicon NPN Phototransistor Detector

This part is the equivalent replacement for the following:
4822-130-41059, 482213041059, BPW76, BPW77, BPW77NA, BPW77NB, BPX43, BPY62, BPY62-2, BPY62/II, CLR2050, CY/BPY62-2, CY/BPY62-II, ECG3032, EPY62, EPY62-1, EPY62-2, FPT-500, FPT500, FPT510, FPT510A, GS612, GS670, MRD300, MRD3050, MRD3051, MRD3054, MRD3055, MRD3056, MRD310, MT2, NTE3032, OP800, OP800A, OP800B, OP800C, OP800D, OP801, RB326-5869, SD5400-1, SD5440-1, SD5440-2, SK2032, STPT51, STPT53, STPT80, STPT81, STPT82, STPT83, STPT84, TIL64, TIL66, TIL67, TIL-81, TIL81, TIL99


He's saying those are all interchangable.

And for the signal diode, what do you recomend that is faster than the 1n4148? I was thinking it was just there it rectify the electricity flow but obviously I'm wrong. I know some but not enough as you can see.

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by lidnariq » Sat Mar 21, 2020 11:09 am

I'm pretty certain that seller is just listing every phototransistor he could come across. Those cover a wide range of peak sensitivities (e.g. BPX43 is 880nm) and a wide range of lens half-width (e.g. BPW76 is 40°). I would probably either just buy the cheapest phototransistor I could and hoped it was good enough, or else I'd try for a better match in terms of peak sensitivity and lens.

The 75kΩ resistor is matched, somehow, to the amount of light-induced current through the phototransistor. Too much current for the resistor when aimed at an off TV and it won't be able to see when the electron beam is right in front of it.

I think you'll be fine with a 1N4148. The diode is just there to absorb energy from the inductor when the 2N3904 stops conducting - otherwise the energy will charge the node to some high voltage.

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nintendo2600
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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Sat Mar 21, 2020 11:50 am

lidnariq wrote:
Sat Mar 21, 2020 11:09 am


I think you'll be fine with a 1N4148. The diode is just there to absorb energy from the inductor when the 2N3904 stops conducting - otherwise the energy will charge the node to some high voltage.

That is what I thought as well. Thanks for confirming that. Also thanks for the clarification on the various photo sensors information. That guy was probably just trying to sell whatever he could. I have a bunch of photo diodes for NES Zapper guns that I changed out for use with LCD screens and the modified binary's for duck hunt,etc. that Russian fella did a short while back. I'm not sure they are ideal for this gun so I will order a couple of those first ones you recommended that are smd. I'll just wire them. That and I'm pretty sure the original mrd310 is still good. I'm ordering the parts to give this pcb a clean slate of parts and I'm also ordering a second set of parts for it that are through hole to redraw this board afterward. After all this work I really want to expand on this from fixing this one gun to making a drop in replacement to put in the common Justifier gun in hopes of also adding menacer support to it. In for a penny, in for a pound.

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by lidnariq » Sat Mar 21, 2020 12:07 pm

You never did answer what the barrel of the GAMEGUN looks like...?

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Sat Mar 21, 2020 3:14 pm

lidnariq wrote:
Sat Mar 21, 2020 12:07 pm
You never did answer what the barrel of the GAMEGUN looks like...?
Sorry I missed that. Pic attached:
DSCF0330.JPG
The sensor just sits in the middle of an orange plastic circle than then down the barrel at the end
is a clear and somewhat magnifying plastic circle. Similar type insert found in most light guns
but this isn't just a window, there is some magnification going on.

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by lidnariq » Sat Mar 21, 2020 4:23 pm

You probably want to choose a half-width matched to the barrel of the lens then. What's the diameter of the far lens, and how far will the photosensor sit from it? There's no utility, and maybe some harm, in choosing a phototransistor that has a half-width larger than atan(separation/(lensradius/2).

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Sun Mar 22, 2020 1:46 pm

lidnariq wrote:
Sat Mar 21, 2020 4:23 pm
You probably want to choose a half-width matched to the barrel of the lens then. What's the diameter of the far lens, and how far will the photosensor sit from it? There's no utility, and maybe some harm, in choosing a phototransistor that has a half-width larger than atan(separation/(lensradius/2).
From sensor to lens it's 10cm. Diameter of the lens hole at the end of the barrel is 1.5cm.

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by lidnariq » Sun Mar 22, 2020 2:06 pm

... I totally remember by trigonometric identities. radius/separation, not vice versa. Sigh.

Anyway, atan(1.5cm÷2 / 10cm) = 4.3°.

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Sun Mar 22, 2020 2:57 pm

lidnariq wrote:
Sun Mar 22, 2020 2:06 pm
... I totally remember by trigonometric identities. radius/separation, not vice versa. Sigh.

Anyway, atan(1.5cm÷2 / 10cm) = 4.3°.
So is 4.3 degrees the viewing angle? You just jumped one step above my pay grade with the "atan". That is totally new to me and I know nothing about it aside from the formula you just provided.

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by lidnariq » Sun Mar 22, 2020 5:09 pm

https://en.wikipedia.org/wiki/Trigonome ... efinitions

Construct a triangle with the lens as the far side, and the phototransistor as the point.

That triangle is symmetric about the center of the barrel, so to make it easy, fold it in half (about the center of the barrel). This resulting triangle has a right angle (where the line going straight out of the phototransistor crosses the lens). So the standard right-angle triangle trigonometric functions hold, in this case specifically:

Tangent(angle) = (opposite side = the lens radius) ÷ (adjacent side = barrel length)

atan, or arctangent, is the inverse function:

angle = arctangent ( opposite ÷ adjacent )

This angle is the same half-angle as for the phototransistor (or an LED, for that matter)

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Mon Mar 23, 2020 12:36 pm

I ordered parts to replace everything on the pcb the other night. I'll replace the through hole components and the transistor first in hopes that does the trick. If not I'll start replacing those smd resistors and caps as needed. 2mm parts suck to work with...lol..

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Tue Mar 24, 2020 4:28 pm

Well this sucks. I replaced every last piece of population on this hunk of shit and it's still pretty grim. I even replaced the cord just in case. I'm hoping one of these smd's might have burned when I put them on, I highly doubt it, but that is why I bought an equal amount of through hole parts to use. Continuty of the whole pcb is fine too. I'm just at a loss. I even tried my NES zapper with duck hunt just to be sure it wasn't just my TV acting up. God this is defeating. :( Only thing I have left to try is replacing the 100pf cap with a 1000pf but it wouldn't be making this much of a difference. I still don't even get a lick of recognition of the sensor on screen when firing, not at all.

EDIT: took a better picture
DSCF0333.JPG

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