Shared Projects by Missingno

Heard a friend stole this one from me. So I ’m just releasing it. +5V Buck Converter. If input needs a better, less noisy output, then put a 220uF 35v cap between the input and ground. A polar tantalum capacitor is required on output because of the laws of capacitance. And tantalum is required due to discharge rate.

Screwing over a friend who stole this from me and got paid for it.

Chip is LMR16030 0805 capacitors are ceramic at 0.1uF 50V Tantalum output cap is 100uF Resistors are 100k, 17.65k, and 50k on RT Sync Diode is schottky of 50V 1.5A

Saved for later - Atari 7800 Mod board - saved for later. By MissingNo (zo) quick and dirty mod board will upload and fix others shortly but this one works like LHE board.

This is an Atari 7800 S-Video/Composite video mod. It also allows for stereo output, between left and right. Much like LHE’s board, this board is designed to drop-in, after you desolder the 74LS32. You then put a machine-tooled socket where the 74LS32 was, and solder pin headers to the underside of the board. You desolder this chip to input most of the luma information from the system.

Yes, there is stereo output. The 7800 MARIA/SALLY chips do not produce any audio. The TIA chip (used in the 2600) is all that is used to synthesize audio on the 7800. Grab TIA Pin 12 and 13 directly from the chip. You SHOULD disconnect these pins from the board. Or you can cut the traces on them so there’s no output to board. Then solder to those pins.

POKEY audio is not really required. But if you own a POKEY chip game (seriously… like 3 games contain a pokey chip) then you need to remove C10 and solder directly the input of C10. I overlayed POKEY ontop of 7800 audio with a 120k resistor. You might ask why I did that for each channel… and simply put, with the 1.8k pullup resistors that are required for audio, you need more impedance on the overlay of POKEY because that is getting pulled up to voltage as well.

This board had no 75 ohm impedance on I/O. If your image is too bright, then you can wire some 75 ohm resistors inline, and from jack to ground (I suggest between the solder cups, and grounding tabs). That should adjust the image a bit. I didn’t put any 75 ohm resistors after FMS6400 output to save space pretty much.

Another thing to note is that I swapped the two connections on the switching TS5 chip, to see if that would stop he vertical dot crawl some get when wiring TIA9 to the board. I didn’t know, though, if output on the 74LS174 Pin 5 was high or low when in 7800/2600 mode.

If you still get vertical scrolling bars/dot crawl on the output, I recommend repurposing the channel switch to turn TIA9 chrominance on/off. You can also do this with a psychical switch and drill another hole into the system, but I dont recommend that.

This little board grabs unamplified Y(luma), R-Y(Pr) and B-Y(Pb) output from a SNES with the board revision SNS-CPU-GPM-01, SNS-CPU-GPM-02, and SHVC-CPU-01.

Grab Y(Luma) directly from multiout pin 7, R-Y(Pr) from pin 1 of the SENC-A (BA6592F) and B-Y from Pin 24 of the SENC-A (BA6592F). And this board will amplify Pr and Pb about as simplify as it can. Connect directly to Component jacks mounted in the system.

The transistor is a KSC945 (2SC945). The pots are 100 - 500 ohm, the 1k resistor is for backwards current protection on the chip, and the capacitors are both 220uF.

Regarding the BA6594AF. You don’t need this board nor any amplification on the SENC-B BA6594AF. Just wire two 220uF capacitors from R-Y and B-Y outputs on the chip to the Component Jacks and you will get perfect video on Pr and Pb. Grab Y from multiout pin 7.

This is a dropin board of batari’s S-video mod schematic for the Atari 2600. (The best Atari video mod in my opinion). The pause mod portion was designed by Victor Trucco.

Notes: The FMS6400 can be substituted with the FMS6410 or ML6428. I already routed 5 volts to ASEL (pin 2) on the FMS64XX so there’s no need to jump it yourself.

The FMS6406 is NOT compatible with board. You will fry the chip if you use the FMS6406

The TIA chip goes on the bottom header row

Jump the RDY Pad if you do not wish to use the Pause Mod. In doing so, you may leave the pause mod unpopulated. C & R pads are still required for audio.

I’ve noticed some eBay sellers, selling some other boards I’ve designed in the past without my permission. I consider this board under the Creative Commons License. If you wish to sell this board, you may (possibly) obtain my permission by contacting me through email.

My email is - [email protected]

This board is quick and dirty. Still can solder to it, it just unprofessional a tad that I didn’t test it, but If you wish to try it anyways, you may. Should work just fine as there’s no continuity errors in eagle.

Also, the board title mentions how there’s “no 75 ohm impedance on i/o” what I meant by that was that there’s no 75Ω impedance and pulldown resistors on the video lines after the FMS amplification. 6 more resistors of 0805 formfactor would actually the board much taller, and I wanted a dropin board that could’ve just worked in the Atari 600 Junior. Probably won’t work in the Jr. anyways, but I wanted it to be as small as possible. If you require the termination and pulldown then simply put some external 75Ω resistors inline with the video outputs, and wire a 75Ω resistor between the soldercups and grounding brackets of your panel mount jacks.

Any good hobbyist will and should have 75 ohm resistors on hand anyhow. So that shouldn’t be an issue.

® Missingno - Creative commons apply. If you wish to sell my board you may, but email me for my permission first.

Part Value Package Library Position (mm) Orientation

AUDIOL Audio Left SMD1,27-2,54 wirepad (14.76375 39.21125) R0 AUDIOR Right Audio SMD1,27-2,54 wirepad (16.98625 39.21125) R0 C Chroma SMD1,27-2,54 wirepad (34.76625 39.21125) R0 C1 0.1uF C0805 rcl (31.511875 30.00375) R90 C2 0.1uF C0805 rcl (33.734375 30.00375) R270 C3 0.1uF C0805 rcl (36.98875 30.7975) R90 C4 0.1uF C0805 rcl (26.82875 34.6075) R270 C5 10uF C0805 rcl (29.05125 34.6075) R270 C6 0.1uF C0805 rcl (18.7325 12.85875) R0 C7 0.1uF C0805 rcl (14.12875 12.85875) R0 C8 0.1uF C0805 rcl (27.305 8.73125) R90 CV Composite SMD1,27-2,54 wirepad (32.54375 39.21125) R0 D1 1N4148W SOD3816X135N diode (41.11625 10.31875) R270 D2 1N4148W SOD3816X135N diode (43.02125 10.31875) R270 D3 1N4148W SOD3816X135N diode (44.92625 10.31875) R270 GND0 GND SMD1,27-2,54 wirepad (37.30625 39.21125) R0 GND10 GND SMD1,27-2,54 wirepad (19.20875 39.21125) R0 HEADERS Drop-in to Socket on Board DIL40 ic-package (25.4 12.7) R0 IC1 74HC4050 SO16 40xx (45.085 31.27375) R0 IC2 FMS6400C SOIC8 FMS64XX (contains all FMS derivatives) (23.1775 34.6075) R0 IC3 74LS00 SO14 74xx-us (35.56 10.795) R0 R1 1.5k M0805 rcl (41.91 24.92375) R270 R2 4.7k M0805 rcl (44.45 24.92375) R270 R3 2.2k M0805 rcl (46.99 24.92375) R270 R4 8.2k M0805 rcl (48.26 37.7825) R90 R5 75 M0805 rcl (17.62125 32.7025) R180 R6 2.2k M0805 rcl (45.72 37.7825) R90 R7 75 M0805 rcl (32.146875 33.655) R0 R8 1k M0805 rcl (36.83 24.92375) R270 R9 470 M0805 rcl (43.18 37.7825) R270 R10 3.3k M0805 rcl (39.37 24.92375) R270 R11 1.8k M0805 rcl (18.7325 10.63625) R0 R12 1.8k M0805 rcl (14.12875 10.63625) R0 R13 1k M0805 rcl (29.68625 8.73125) R270 R14 1.5k M0805 rcl (29.68625 13.0175) R270 R15 1k M0805 rcl (43.97375 13.81125) R0 RDY RDYtoTIA SJ jumper (7.14375 8.334375) R180 SW1 Switch Connection 1 SMD1,27-2,54 wirepad (49.37125 12.065) R90 SW2 Switch Connection 2 SMD1,27-2,54 wirepad (49.37125 9.36625) R90 TIA TIA (Stella) DIL40 ic-package (25.4 8.89) R0 U$1 1k TAYDA-POT Tayda-ThruHole-Pots (Helder) (26.82875 26.67) R0 U$2 1k TAYDA-POT Tayda-ThruHole-Pots (Helder) (18.57375 26.67) R0 Y Luma SMD1,27-2,54 wirepad (30.32125 39.21125) R0