Commodore 1702 Teardown and Ghost Busters cartridge build

[@Schiizom]

👍

[@tony359]

OMG the coolest cartridge ever!

[@Epictronics1]

Looks great in the display cabinet by the side of a C64 :)

[@tony359]

@@Epictronics1 You have space for a display cabinet! 🥲

[@Epictronics1]

@@tony359 I'm lazy. Stuff in display cabinets never gets dusty and doesn't need cleaning :D

[@douro20]

Colour CRTs often have a dark treatment and sometimes anti-reflective coatings on the glass to improve contrast. Several CRT makers in the late 1970s also worked on phosphor formulations which absorb less incident light to improve black levels- hence the term "black stripe".

[@senilyDeluxe]

Nah, I'm thinking, if you observe the little black stripes between the R/G/B stripes* on the front of the CRT - on older CRTs these are usually silver and often a little wider. If they aren't, they're likely to bend under heavy electron bombardment - showing a bright picture for just a few dozen seconds warps the shadowmask and the colors won't match afterwards until it cools back down. Black Stripe CRTs don't have that problem. A few of the very latest delta gun CRTs had that same technology, so maybe I'm totally wrong here. *) helps if you're near-sighted (or use a magnification lens)

[@douro20]

​@@senilyDeluxe I believe they did both- developed phosphors which were darker in the ground state and made the stripes between the phosphors darker.

[@g4z-kb7ct]

blackstripe is a trademark. nothing to do with the technology..... a company making something is not going to give away their IP and trade secrets in the name lol

[@jasmijndekkers]

Great job you did. Steven is now working on a Amiga 500 for a customer. Have a nice and safe trip. See you next week we hope. Greetings from Steven from the Netherlands

[@Epictronics1]

Thanks! Good luck with the A500

[@solzarcat555]

nice I like seeing inside of CRT monitors, super interesting.

[@charonunderground8596]

Good job !

[@Epictronics1]

Thanks!

[@davidmckendry4491]

@@Epictronics1 please don't copy that floppy 💾 😊

[@jozsefizsak]

Always fascinating!

[@Epictronics1]

Thanks!

[@RacerX-]

Nice work, as always. That appears to be the more rare 1702T variant. I have a regular 1702 and it does not use the Toshiba tube. It also does not have all that metal shielding, IIRC. I think it is mostly the same but according to the Service Manual there are some differences in components to accommodate. As for logic chips, HC chips are High Speed CMOS. The C64 uses TTL levels so although they tend to work they could cause problems due to the nature of what is a low and a high level in TTL vs CMOS. HCT chips are what you want for TTL levels. I usually just use LS chips as they seem to be the cheapest and do use less power compared to non LS. I am simplifying this from an article some engineer wrote that is way over my head. ;-). If you look on melon64 forums there is a great explanation that is easier to understand then engineer speak.

[@Epictronics1]

Cool. I don't have access to a regular 1702 for comparison with this T model. It would have been interesting to see if there is a difference in image quality.

[@RacerX-]

@@Epictronics1 thats what I was curious about too. It is so hard to tell on a video. I do know that my 1702 is very sharp and I have been using it since the 80s.

[@krizator]

Very nice cart

[@Lightrunner.]

Ghostbusters 🥰🥰🥰🥰🥰🤗

[@g4z-kb7ct]

The 17-series monitors are all on life support. The flyback was not copied by HRDiemen therefore not available new so when the flyback dies it's game over permenently. For logic, the modern type is HCT and that's what you should buy if getting new chips from places like mouser etc.

[@Epictronics1]

Luckily, this one doesn't seem to have been used much. Hopefully, it will last!

[@davidmckendry4491]

Needs a floppy 💾

[@nickwallette6201]

I seem to remember that, as a kid, this game took f o r e v e r to load from floppy. I didn't know there was a cart version of it. (Or maybe you can turn any disk image into a cart? Not really a C64 expert.)

[@davidmckendry4491]

@@nickwallette6201 I love using floppy disks such an amazing format and so nostalgic just like cassette tapes.

[@nickwallette6201]

@@davidmckendry4491 Sure, same here. Was just working on an old P6 system yesterday, with a stack of boot and utility floppies.

[@ShaolinDave]

​@@nickwallette6201 My understanding is that you can turn any C64 software into a cart _if_ it fits within the RAM using a single load. So a game like "Castle Wolfenstein" that loads between each screen wouldn't work without some serious hardware and software trickery. From the looks of it, games that don't require such trickery are organized into a "64K" folder here. I see "Ghost and Goblins" is in the list, iirc that game actually had several levels cut specifically to make it fit within 64K.

[@xero110]

If you are experimenting with video length. For me the magic number is ~25 minutes. 25 minutes just seems to fit into my schedule more. I know short vs long videos is a battle ground now. I'm on YT for long videos, because I have the attention span.

[@Epictronics1]

This is pretty tricky. YT seems to promote longer videos but it isn't easy to find the time to make longer videos every week

[@nickwallette6201]

15-25 min is indeed about the right length. Long enough to be engaging, but not so long that I start to schedule it for "when I have time" until it falls out of the queue.

[@mcbeav]

Can you point me to the soldering iron stand you have that is attached to your pinecil? That seems incredibly convenient, but I can't find anything like it anywhere.

[@Epictronics1]

it was included with my TS-100

[@mcbeav]

@@Epictronics1 Ah, damn! Thanks for the response!

[@tigheklory]

I love my 1702, but the focus voltage is all over the place once it warms up. It really needs a new flyback but nobody makes them anymore.

[@mrnmrn1]

It might be leakage in the CRT socket, or in the focus / G2 divider, which is separate from the flyback I think. You can try to disassemble the socket and clean the tube around the focus pin. The plastic rim usually can be removed carefully from the end of the tube so you can clean the glass around the pins, and the plastic rim itself. The socket has a spark gap for the focus voltage, if you disassemble the socket and wash that area with IPA it might help. But it also can be a tube fault, which is still better news than a flyback failure, because you can swap the tube from almost any TV with the same size (unless these are high resolution tubes, but I don't think they are).

[@YT32-16branch]

1701/1702 Pal/NTSC

[@retropcs88]

Ah nice way to relax after cursing out the 3 Xboxes in my workshop which I somehow broke 🤣

[@Epictronics1]

ooch, I hope you can fix them :)

[@nickwallette6201]

As they say, "everything works out OK in the end -- if it isn't OK, it isn't the end." Or something like that.

[@AnthonyRBlacker]

I wonder if a 'magic eraser' (melamine) would have taken that white stuff off of the monitor? I don't know though, it may have removed the brown under it though.. that would have been bad, but I don't know the melamine works REALLY well for stuff like that.

[@Epictronics1]

I love magic eraser, it's truly magic! :) It is slightly abrasive though, so I use it as a last resort when nothing else works

[@Torbjorn.Lindgren]

74HC273 might work as replacement but why bother when the 74HCT273 is just as easy to get AND is guaranteed to work? (that's what the T in the model name stands for).

[@BigBadBench]

Reinforcing your CRT warning! Got zapped by a tube today. It’s not fun!

[@Epictronics1]

ooch, that sucks!

[@nickwallette6201]

Not possible! Everyone knows that you will die immediately upon opening the chassis of a CRT! ;-D The only ones that live to tell about it are trained technicians with naturally high impedance.

[@Epictronics1]

@@nickwallette6201 lol

[@awilliams1701]

I kind of hated this game because I was always broke in the end. lol

[@Epictronics1]

You need to catch the ghosts quicker 😆

[@awilliams1701]

@@Epictronics1 I always lost buildings to marshmellowman. I did everything I could. NEver managed to get anywhere.

[@nickwallette6201]

@@awilliams1701 You just gotta try S'more.

[@ShaolinDave]

@@awilliams1701 If you do nothing to stop him, yeah, he'll always cause more damage than you can possible make up for and you'll wind up losing. I guess the way you're _suppose_ to fight him is by using the "marshmallow detector" item. It makes a building turn purple before he attacks, so if you wait there for him you'll wind up defeating him. I never knew that growing up, because I had a pirated copy with no instruction manual. The way I beat him actually might've been a glitch. Instead of the marshmallow detector, I'd use the ghost bait. When you see the ghosts are about to form into Marshmallow Man, quickly push "B" on your keyboard and they'll be lured to your current position, causing you to automatically defeat him.

[@senilyDeluxe]

Hm. My 1701 has a fine-pitch shadowmask (and I have stacks of TVs to compare it to). Eons ago I was given a C128D with some games, a printer and said 1701. And when I found out that through an adapter I could hook it to my VCR and watch TV and the picture was a lot better than my cheap TV (sharper AND brighter), I pretty much stopped using my regular TV (which didn't like that and died). It's probably all black inside from the hours of use. Just a few years later I snatched a 1802 for a tenner and was disappointed that it had a regular pitch shadowmask. It also felt cheap, looked cheap and had a cheap picture - exactly like my cheap old TV when it was still working.

[@Epictronics1]

Someone mentioned that this might be the T model of the 1702. Maybe there is a difference? I'll compare it with the 1901 which is a magnificent chroma/luma display

[@senilyDeluxe]

@@Epictronics1 There's also a huge honking circular metal can on the right side and I think I read somewhere that the 1701 uses a transformer power supply whereas the 1702 uses a standard switch mode PSU. And the CRT being different.

[@ScottyBrockway]

1702 has much better colors than other commodore monitors if it has a JVC (I think it was JVC, might be Phillips) tube. Same with the 1902 for 80 columns. The other monitors are very washed out looking and don't have very good saturation.

[@Epictronics1]

This 1702 has significantly nicer colors than my 1084-P