rasch_C

Payment sent. -Allen

Looks like I did not order this originally. If like to get 1 of the full-size sets. Is the PayPal address still the same and same price? Thank you, Allen

Has anyone heard a firmed expected ship date? They stated on their website they expected to ship in August. On another note, it looks like playasia is releasing the Japanese MD cart? (https://www.play-asia.com/ultracore/13/70cuzj) -Allen

Yeah, there's always some lag/delay between the counter and flipping the switch on for the sale. I believe I run into this with Limited Run as well. You have to just keep hitting refresh when the countdown runs out until you have the add to cart button. Sux that you missed out -Allen

Just received an email from Strictly Limited: THIS IS COMING TO THE GENESIS/MEGA DRIVE!! -Allen

Looks like Strictly Limited just announced release date of April 28 for PS4 and Nintendo Switch. I was hoping the collectors edition (or some variant) would've had the game on Genesis cart, but it only looks like the game on modern console, poster, soundtrack CDs. I am really baffled as to why it is not being released physical for the console it was originally designed. -Allen

I thought Waggie reached out to the original author and got his consent/permission as well. -Allen Sent from my Pixel 2 using Tapatalk

I had my timescale backwards in my head. At .1 sec (all the way counter-clockwise) is when it shows just the sweeping dot and then 10 Msec is when I see the sweeping signal (the complete trace does not stay lit). It goes dimmer as I continue to go clockwise making it really hard to see. I did just play around some more with it tonight - getting a better feel for the scope. I set to Multiplier 1, 10uS timebase, DC, Negative trigger. Put my Volts/Div at 1 and reading pin 3 of U3 while power is on the trace went up 3 reticles and was a flat line for the complete width - I believe this would be indicating 3 volts? -Allen

I don't know about big spender, but I suppose it is more than the $10 I have into this old Heathkit The Rigol seems like the best value entry-level scope. I could get a used Tek scope or something for less, but I determined that I want to have a modern scope for the kids in the Makerspace and it is more compact. The space is very limited. I tried going to 10us, but the trace was not persistent. You would just start to see the trace go from the left to the right of the screen. At the lower setting you would just see the dot moving from the left to the right. I believe the last pic is at the 1 multiplier. Am I seeing the color-burst at the start of that signal? We are definitely beginners using a scope. I'll see about firing everything up tonight and testing on U3. Thanks again, -Allen

So, now that we're finally out of the -30°F temps .... brrr, that cold caused a lot of issues including taking my internet out for multiple days! After locating all the caps for my old scope and realizing that it would be ~$90, I decided it is not worth it to recap it. I did only spend $10 for it at a hamfest and thought it would be an easy way to get my feet wet. I am planning on buying a Rigol DS1054Z shortly. I decided to breadboard the easy composite mod and temporarily test that to see if I get picture. Still not getting a picture I have attached pics of the signal reading on my scope - it works roughly, but I don't know how well or accurate. -Allen Sent from my Pixel 2 using Tapatalk

PM sent. -Allen

Looks like at this point I'll get my scope up and/or just do the A/V mod. I've been having a heck of a time locating some of the precision caps in the correct specs. I'll spend my night tonight hopefully tracking them down and ordering them now that my laptop is back up, and maybe order an A/V mod. Give some time for parts to come in and I'll report back with either results from a working oscilloscope, or a working console after A/V mod. Thanks again for all your help! It's been a great learning experience. -Allen Sent from my Pixel 2 using Tapatalk

A couple obvious reworks, and others are questionable. Sent from my Pixel 2 using Tapatalk

I was going to ask about the French of that. I was reading up today on the constriction of an NTSC composite signal and then though about my reading and wondered about the mismatch. So, what I should be reading at this location is in-fact the horizontal frequency? My plan is to composite mod this. So, if the RF modulator is bad, I don't really care. I'm just hoping to verify a working console before modding. -Allen Sent from my Pixel 2 using Tapatalk

Yes, I have still been working on this, but it's been cold here and the lab is in the garage which is a pain to get up to acceptable working temp w/ my kerosene heater. Also, I have been rebuilding stuck my laptop. I would have to remove the RF box to gain access to it (cover is on the PCB side). I did try pin 3 of the RF-PCB connection to the composite video input of my PVM directly and only had brief interference show up from actual touching of the signal pin. PVM does not indicate lock of signal of any type. This is w/ and w/o cart. I also measured freq. of pin 3 and it varied between ~12.5kHz - ~13.5kHz. I'll have to take pics of the reworked components and post. I do believe you guys are correct about Q4 and even the resistor on the RAM chip (didn't look like a rework to me, I was just curious on that one). There are a few components that have been reworked, however. Thank you, -Allen

I'm kinda digging that case. GLWS! -Allen

Last year went OK, but still didn't get my next console as intended. If you remember, I was planning on finding a Jaguar, Vectrex, or 3DO for my next console. This hasn't materialized yet. So, that goal carries over this year (thinking about TurboGrafix 16 as another possibility). Other than that, the bullet points for this year: Learn / go through more hardware - currently fixing my 7800 as posted in another thread, I also have my Sega CD model 1 to finish, and a PS4. As well as learning more on the electronics side more. Commodore - continue expanding this collection and playing around with it (hardware and software) and get my 12yo son his own C64. Programming - really delve into 6502 assembly and 2600 programming. And, above all Family Time with hobby - Having my 12yo son go through the hardware things with me and expanding his own interest in C64 stuff. My 15yo daughter wants to start her own collection. We have had that talk and discussed on what she wants to collect, what her interests are, and determined her start would be best collection GBA (GB, GBC, GBA). Play more games with my 6yo son (as soon as we find where Bendy on the Switch has been lost to). Also, we may finally make an appearance again at MGC this year. -Allen

Fresh set of testing eyes today. Thank you ChildOfCv for turning me on to the freq. feature of my meter! Pin 3 of MARIA measures at 14.13Mhz -don't know how accurate/valid that is as that is outside the range of my meter. Pin 6 is 1.192Mhz. Pin 7 is 3.578Mhz. Pin 8 is 1.789Mhz. Pin 3 of the RF modulator connector to the board measures ~3.308V. Grounding for RF modulator is good. Pin 3 to output (center) measures 7.52 kOhm, pin 2 to output measures 0.618 kOhm, and pin 4 to output measures 52.5 Ohm. -Allen Sent from my Pixel 2 using Tapatalk

That's good to know about the clock being A/C. I can try to retest those knowing that. I have an Extech 430 meter. I do have an old scope that I've been meaning to recap and use to learn. I currently have it on my other bench in order to go through with the thought I could use it for this project. I thought I already bought the caps for it, but it appears not. Yes, the components I am talking about are obvious reworks including the Q4 position. I'm going to start with the absolutely known reworks and go from there. There is also a resistor soldered directly to pin 21 on one of the RAM chips. I'm not sure where that goes or what it's for. Thanks for your help, -Allen Sent from my Pixel 2 using Tapatalk

I currently have the board in my Panavise now. Reason? Upon further inspection, it looks like 10 components have been replaced. I believe spots on the board are a mixture of resistors and capacitors, but they have all been replaced w/ resistors. This includes the aforementioned Q4 location. I will start desoldering these components and then I'll be able to read the locations (why didn't they mark the board next to the component instead of underneath?) I do have a 2N3904 transistor so I should be good there. Probably will stop for the night and doubtful I'll get to it tomorrow. Idk if maybe it was somebody's attempt at a mod that went wrong or what, but the best immediate course is to get it correct first. -Allen Sent from my Pixel 2 using Tapatalk

Forgot to add.... It measures 1ohm Sent from my Pixel 2 using Tapatalk

After looking more closely at my pic that I just uploaded in my last post, I noticed something strange. Some weird resistor is in place of the Q4 2N3904 transistor. Board is CA025234- Does anyone know why someone would replace Q4 with a resistor? I have gone over the board and nothing else looks out of place. I will see if I have an equivalent transistor in my lab to replace. Thanks, -Allen Sent from my Pixel 2 using Tapatalk

Pins 3 & 8 of MARIA are steady at 1.246V & 4.92V respectively (0V w/ power button off). Pin 6 starts at ~1.939V and decays at rate of about 1mV every 3-4 seconds. This is also 0V w/ power button off. Pin 7 starts at ~0.745V and also decays at rate of about 1mV every 3-4 seconds. This is ~0.7V w/ power button off and shows similar decay rate. W/ 2600 cart in, I checked LUM and Color lines from TIA and MARIA. TIA was showing ~21mV on most these lines (I believe LUM was lower if memory serves) and MARIA was showing ~15mV. I think I'm going to check U3 next. I do not currently have a scope up. Also, can anyone inform me of the pin numbers for the RF connector (J3) as I am not seeing labels for that on the board? Thanks again, -Allen Sent from my Pixel 2 using Tapatalk

I forgot to mention, this is an NTSC console w/o expansion port. -Allen

Just a quick update. I did test Vcc, Vdd, etc. On the major ICs (TIA, RIOT, Sally, Maria). I thought I might have narrowed it down to being held in reset because the reset pin on Sally is always high when power switch is on, but going through the schematics and my understanding of how U10 works this is normal (pin 13 on U10 goes high and then goes through an OR gate and then to the reset pin on Sally). All power at major ICs seems to be appropriate via the testing done so far. I'm still going through the schematics and am starting to understand better the layout. I will do some more probing yet, test the logic chips, etc. Is there a better (high-res) schematic for this somewhere? I have the one(s) off AtariAge printed out, but it is still fuzzy. Thanks, -Allen Sent from my Pixel 2 using Tapatalk