emerson

I used a PIC microcontroller to interface both PS/2 keyboard and mouse with the NES. I was attempting a Family Basic keyboard replacement and while I had some timing issues with Basic itself reading my circuit my own homebrew code worked perfectly fine. One day I will rewrite my code in assembly and get it working correctly with Basic. PS/2 devices will buffer data if you hold the clock line low which allows you to both control when the device is read and/or halt reading the device for whatever reason. PS/2 devices provide their own clock signals to the master device so you have to monitor the clock line and read the data line when appropriate. PS/2 devices can also be programmed to operate in a specific mode which is beneficial as they do not all default to the same mode on power up. My approach to a 2600 keyboard would utilize a PIC and an SPI style protocol to transfer data to the console. The PIC reads and buffers keyboard data until the 2600 is ready to receive it. When the 2600 is ready for data it sets a ready flag on the joystick port. When the PIC sees this ready flag it waits until the keyboard is finished sending data, halts keyboard transmission, and clocks the buffered keyboard data into the 2600. Once all the data is sent the PIC would release the keyboard and read in any buffered data from it. A total of 3 I/O lines would be required from the joystick port. I am unsure of the max current of the 2600 joystick port and there is conflicting data on the max current of a PS/2 device. According to my research it's either 100mA or 275mA. This may be respective to 6-pin mini DIN and 5-pin standard DIN keyboards but that is just a guess. Edit: Another option might be to simply use a serial to parallel shift register and utilize both joystick ports as a parallel bus to read the data into the console. The cable would look like a stethoscope.

@CapitanClassic and I are in the same page! I saw this post yesterday and immediately pulled out my BNYUFF Year Two vhs to watch Lick of Fury it after reading this post! save_the_drama.avi

Not sure if any old 6502 will work but I bought one from these folks a few months ago. They have a few different types. http://unicornelectronics.com/IC/6500.html

I always enjoy the game Pushover. You play as an ant solving domino puzzles. The dominoes have different abilities like infinite rolling or exploding or falling upward. You rearrange everything to knock them all down before time runs out.

The Battle of Olympus is up there for sure. https://www.youtube.com/watch?v=LKlP7q0Xpqw&list=PL65BA686F70BA4AA3

I will recommend the sharp twin as well. The all in one solution is very convenient. Because the controllers are hard wired I opted for the AN-505-BK turbo model. The only thing I don't care for are the short controller cable lengths but that's an easy fix.

Let me know if you change your mind on shipping I'll take that commodore monitor.

Unfortunately no. Those were some of the first ones to go.

I placed an order with Unicorn Electronics and tossed in a few of these connectors. They appear to be a perfect match! It fits well into the cartridge slot and pins extend beyond the pcb clips of the plastic housing this screws into. I see no reason why this won't work. The white connector is a used pull from a 2600 and the black connector is what I just bought.

Here is another forum post with a similar question to yours and a similar answer to mine: https://forums.pimoroni.com/t/adding-an-external-volume-control/9824 So DAC stands for Digital to Analog Converter. In the link I posted above they mention the pi actually has two audio channels that tie into the GPIO header. An easy approach to convert the 2-bit digital audio into analog would be an R-2R resistor ladder. Another approach is to use binary weighted resistors where each resistor is twice the value of the resistor before, with the lowest resistor being the hightest bit. With that being said, and assuming they used a resistor DAC, you would look for resistors in close proximity that are equal and/or close multiples of eachother in value. As for the potentiometer, your options would be to either use a dual gang pot and tap into the circuit from the GPIO header or use a single gang pot and tap in after the DAC. Tapping into the GPIO would be an easier approach for someone who is not confident in their skills but willing to give it a try. Based on the traces I believe the small square microchip with pins on all 4 sides (QFN-16 package?) is the power amplifier. Are you willing to provide a close up image of the area boxed in red?

I read my previous post and now realize I should stop making posts before the morning coffee. To clarify my previous thoughts... I am assuming that because the Picade speaker is 5 watts that there is some onboard power amplifier similar to an LM386 that is driving it. I am also assuming the because this is some flavor of Raspberry Pi that the audio is a logic level PWM signal coming from a GPIO pin. In order to couple the GPIO pin to the onboard power amplifier there should be some passive components which could be removed to open the circuit. The potentiometer (plus the removed component) would be re-inserted into the circuit in a potential divider configuration resulting in full volume control to the input of the onboard amplifier. Hopefully my idea makes sense now. A more definite solution could be had if a schematic or high-res photos of the circuit were available.

Could the volume pot be installed between the audio source and power amp input in a potential divider configuration as Stephen described above? There is likely a passive component between the audio source and power amp input that could be removed to open the circuit and prevent needing to cut traces.

Sounds like you need a wire wrap edge connector. This link may have what you need but the site has a $30 minimum. I poked around and they have some interesting stuff! Part# COCE24WW: https://www.unicornelectronics.com/Connectors/coce24ww.html

The below links are useful when determining an appropriate heatsink, or if you need one at all. https://www.petervis.com/electronics/Voltage_Regulator_Heatsink/Heatsink_for_TO-220_Voltage_Regulator.html https://www.petervis.com/electronics/Voltage_Regulator_Heatsink/heat-sink-calculator.html I plugged following values into the calculator. These came from the L78S05CV datasheet and power requirements labelled on the bottom of a TG16 I saw on ebay. It says a heatsink with a thermal resistance of 25.6'C or below is required. Tj = 150 Ta = 27 Vi = 10.5 Vo = 5 I = 0.73 According to the calculator results, the heatsinks in this link are sufficient: https://www.mouser.com/Thermal-Management/Heat-Sinks/_/N-5gg0Z1yzvvqx?Rl=5gg0ZerfnZ1yyp1k2Z1yyp1luSGT&Keyword=to220&FS=True&Ns=Pricing|0

I'm looking to completely sell my collection. It is really awesome of you to offer to help me out like that though! That is most appreciated! Someone else ought to scoop these up, and buy some of mine while your at it.

Bump-civilian! https://www.youtube.com/watch?v=GG4qEzPsbo8

The link below might work. Also attached is my file for the intellivision rgb mod I designed as a template for you to work from. WinCupl is annoyingly strict, so good luck. https://pcwin.com/Utilities/Misc__Utilities/WinCupl/download.htm wincpul_template.pld

Plenty have sold and plenty good films are still available. If you can guess my favorite film you can have it free with any purchase.

I don't see this working with a stock mmc3. Maybe one of the non prg related registers could be repurposed. Seeing how most modern mmc3 homebrew pcbs use a cpld you could easily program one to function similar to the mmc3 but with expanded memory capabilities. Because mmc3 only looks at the lower 6 bits when selecting a prg bank, you will need to add additional registers to control the expanded memory. Another problem you will run into is emulator support. More specifically, convincing emulator devs to support your new mapper since it is no longer mapper 004. What do you need 4MB of memory for?

I look forward to seeing your other items but please send any future pictures via PM. Thanks!

=====LOWERED PRICES 02/17/2022===== - $5 are now $2 - $8 are now $5 - 25% off box sets and individually priced $10 minimum please. I have decided to sell/trade entire laserdisc collection as both of my laserdisc players stopped working and these have been sitting unused for a while. They deserve a new home. Most all of these were bought on ebay. I tried to get widescreen/letterbox when possible. I hope to replace many of these laserdiscs with dvd copies eventually. Also included are a few vhs and dvds I no longer want. Prices negotiable on bulk orders. Prices do not include shipping. Trades are not limited to the items on my list, this just gives a general idea of what I am looking for. If you have similar stuff feel free to make an offer. I am quite flexible with trades! Send me a pm if you are interested in anything. I can only ship on Saturday due to my work schedule. Thanks! My wishlist: https://drive.google.com/file/d/1ATozmhQI4CQob1BCEUYMKX2AVfVPzMda/view?usp=sharing ====================LASERDISCS==================== =====MAKE AN OFFER===== Half Baked [LD 83586-WS] Possession [DLZ-0151] =====$5 LASERDISCS===== Apocalypse Now (2 copies) [LV 2306-2WS] Blue Velvet [692] Cromwell [30639] Guilty By Suspicion [12053] Moby Dick [4635-80] The Eighth Day [ID3977PG] The Sting [11-001] =====$8 LASERDISCS===== Chinatown [LV 8674-2WS] Das Boot [99916] Goodfellas [12039] Meatballs [VL 6009] Tombstone [2544 AS] =====COMPLETE SETS===== $40 - Lady Snowblood w/ inserts (2 films) [AD097-024, AD098-025] $65 - Lone Wolf and Cub w/ inserts (6 films) [AD097-001, AD097-002, AD097-003, AD097-004, AD097-005, AD097-006] $10 - Lonesome Dove box set (4 discs) [ID2453CF] $30 - Murder, Anyone? Laserdisc Games w/ inserts (2 discs) [V-MD-82-001, V-MD-83-002] =====INDIVIDUALLY PRICED===== $20 - El Topo [NDH-104] $25 - Man Bites Dog [CC1367L] $20 - Salo [CC1361L] $25 - Shogun Assassin [12-013] ====================VHS==================== =====MAKE AN OFFER===== Julien Donkey Boy =====$2 VHS===== Frankenstein Meets the Wolfman Mr. Bean Shock The Frighteners =====$5 VHS===== Atom Age Vampire Horror Classics (4 tape set, Vampire Bat replaced with Attack of the Giant Leeches) The Brain That Wouldn't Die (sealed) The Hands of Orlac Walking With Dinosaurs (2 tape set) ====================DVD==================== =====$5 DVD===== Evil Brain From Outer Space DeadLands: The Rising Fists Of Fury The Chinese Connection =====$8 DVD===== Mark Of The Devil 666: The Moralist Safe Inside

Here are my observations: $0040-$005f and $0060-$007f appear to be mirrored registers once the pieces appear on screen. It appears that $0060-$007f is being copied to $0040-$005f. =====AFTER SELECTING LEVEL 9 HEIGHT 0===== (It's black for a few frames. I didn't count these as nothing significant seemed to happen.) frame 0: The playfield occurs on screen frame 1: $006e is loaded with #$a0 frame 2: $00a8 is loaded with #$0c frames 3-13: $00a8 decrements from #$0c to #$01 frame 14: Lots of stuff happens here. Most notable are: $006e increments and is copied to $004e $0065 increments and is copied to $0045 All registers on each frame appear to be copied from $0060-$007f to $0040-$005f from here on. At this point $006e and $0065 both increment until $006e overflows. Once this occurs $006e remains #$00 until you hold down on the dpad. Then $006e loops between #$01 and #$02, incrementing $006f on each loop iteration. Once $006e overflows then $0065 seems to become the frame counter and determines when future pieces fall. $0065 counts from #$00 to #$0b when the sound of a piece landing occurs, and #$00 to #$05 when a piece is falling at normal speed. When holding down on the dpad, $0065 loops between #$00 and #$01. I agree it seems like a very long delay but I wouldn't consider this a bug necessarily. The above process occured every time I tested and reset to check different variables, say two dozen times give or take. It would be very easy to determine where in code these timer values are and hack the game for different timing. Heh, I should have checked here first: https://datacrystal.romhacking.net/wiki/Tetris_(NES):RAM_map

I suggest researching how high voltage lines are run in vacuum tube amplifier chassis to negate interference in the sound. I would desolder the bus strip from the hot leg of the switches and run twisted pairs of hot and neutral lines to each switch. Run them around the bottom perimeter of the enclosure with three pairs on each side. Gut some old ATX power cords if you need the appropriate gauge wire. 16 AWG would be preferred but 18 AWG would be just fine for computer use. Have you verified the wall outlet you are plugging this into is properly earth grounded? You can find testers for this at most hardware stores for about $10.

Actually, according to the article it only supports 1280x1024 or 1024x1024 so the monitor may not work at lower resolutions. If you're lucky the smaller image would be tucked in the top corner of the screen. Internal and external adjustments could possibly center it. Certainly worth a try.

This article has some information about the monitor: http://ohlandl.ipv7.net/video/6091-19.html The monitor supports both sync on green as well as external H and V sync, which are the white and black inputs respectively. Inputs are the bottom row of BNC connectors. You want the switch on the back of the monitor set on 2 for 75 ohm impedance. The mode switch on the front will depend on the sync you provide. According to the article this unit only does 60Hz or 67Hz refresh rates so european consoles may pose an issue? I dont know anything about the amstrad gx4000 but a quick search makes it seem like a european console. If you are in the states I suggest testing with a known good rgb console like a ps2 to ensure the monitor works well before testing PAL consoles. You may need an external circuit to either create a sync on green signal or split a composite sync signal into separate H and V syncs. This looks like a cool find, good luck!