flip
-
Content Count
137 -
Joined
-
Last visited
Posts posted by flip
-
-
Thanks guys!
I may end up keeping the Visicom. Looking into modding this one if possible so I can put it to good use. It's too cool to just sit on a shelf and look pretty.
Hey Tony,
If you change your mind about the Visicom, I would be interested. Let me know if you do!
Cheers,
flip
-
Hi again everyone,
Just an update on the multicart: there appears to be an odd problem with newer consoles. Unfortunately, that seems to be the majority of machines... The cart as it's currently designed works fine on an old machine. The handwritten number on the PCB is below 10,000. On newer machines, some games work. Most notably, the RCA games work as do some of the homebrews. Others simply refuse to initialise and/or crash the system... There's either a subtle hardware change (the older machine doesn't use a 4042 latch/4001 NOR combination, but has a flip/flop and NAND gate to address the different address banks) or RCA updated the system ROM... Since all coding I understand was done on emulators, it's possible they all use an early system ROM dump... I might have to dump the system ROMs from a newer system to compare, but not looking forward to that...
If anyone has any idea as to what could cause this, feel free to make suggestions.
flip
-
Hi to everybody,
I have this console, the italian version of M-1200 Sheen or Conic.
You can see some more images of Trevi console at this link:
http://fabrizios.pix...om/trevim-1200/
I'd like to sell it so if you are interested in it....let me know.
Bye
Fabrizio
Hi Fabrizio,
I would be very interested in buying this - I will contact you via messaging.
flip
-
Hi all,
Proud to present the pcb prototype of a multicart for the Studio II: it has 16 slots, selected by the rotary hex switch. The device works as expected, but there's some unexpected glitches in some of the titles - not sure whether it's my Studio II that has issues or whether something else is wrong...
The design for a 128 slot version using 2 switches is as good as ready. The intention is that the PCB will fit in an original shell (thanks to toymailman!), meaning i'll probably need to use a PLCC chip rather than a conventional DIP version (unless I solder it without a socket, but then it would be hard to update).
Can't give you a date for a final version, but it shouldn't be too long.
flip
-
5
-
-
Hi Flip,
Try the one attached; I think that should work.
Cheers, Marcel.
Brilliant - thanks. Seems that I had a B0 somewhere instead of BC...
flip
-
Has anyone tried the programming cart mentioned in this post?
I've typed in the code in the article, but there's either a bug or something else goes wrong, as the screen seems corrupt for the first few digits appearing...
I guess it makes sense to include it in a multicart, since there's enough slots, but it would be nice to know it's working correctly....
flip
-
Also, my offer to donate RCA Studio carts for such a project is still good. I have about 40 or so available.
I've no idea what the maximum size of the PCB can be for it to fit a case. I only have one cart and am reluctant to crack it open to see... Can I PM you to see whether we can swap a multicart against a case or two? That would allow me to see how everything fits together?
Cheers,
flip
-
That would be great!
Here is a nice chart tld1985 made that lists all the programs for the compatible systems:
23 programs total as bingo is listed twice.
Of course some still are not dumped.
I don't remember how many homebrew Roms Paul Robson made....maybe 3-4?
Someone else might remember and have a list.
Thanks - I've put the list + other roms I know of into a Google Sheet
The top row would be one of the hex encoders, the left column the other. As it stands, 47 slots would be filled (some with duplicates). Using an 8Mbit EPROM, 209 slot remain empty, which is a lot. So a 4Mbit EPROM would be enough (leaving 81 slots free).
One caveat: I've tried contacting Lee Romanow to ask his permission to include his ROMs, but haven't heard back. I'm not looking to make this a commercial product but his license is nevertheless restrictive (e.g. distribution is only allowed in ST2 format). Not sure he's on this forum or if anyone is in touch with him but if you are, I would be grateful if he could get in touch.
flip
-
1
-
-
I am definitely in for 1 when you get them in production!
Nice work!
Yeah it would be nice if you could go more than 16 slots, because if all known programs get dumped there would be about 23 titles then....more if you added the few homebrew roms that were made...
If I use an 8Mbit EPROM (27c801 or 27c080), I have 256 slots. Using 2 hex encoders, as BigO suggested, would enable those to be selected. Having so many slots could enable some sort of organisation: 0x00-0x1f (32 slots) would be RCA originals; 0x20-0x2F (16 slots) would be Paul Robson's games, etc. Does that make sense? I guess it would even hold the games for other, compatible systems as well...
Is there a definitive list of official & homebrew games somewhere that I can copy and paste from?
flip
-
2
-
-
Awesomeness!
Put me down for a copy whenever they're available. Would there be a way for more than 16 titles to be played via this method?The initial version is designed for 16 titles - for simplicity, it uses a rotary hex switch with 16 positions (0->F) to select the game you want to play. I might try and expand that in a second version, but I'd like to get this one up and running first...
PCBs are ordered. I'll post an update when I get them...
flip
-
2
-
-
Hi all,
Haven't posted in this thread before, but incredible work being done in this group!
I've decided to have a go at building a S2 multicart, based on the info on Paul Robson's page
Using a 2764 EPROM that holds two games, the protype is working. It also confirms that Paul's design is correct (as if that was in any doubt)!
Next step is to design a PCB to hold a 27c512 that has 16 game-roms, using a hex decoder switch to select the games.flip-
5
-
-
Hi,
Found this topic just now, so apologies for bumping such an old issue. Did you ever manage to solve the issue of missing pixels? I had the same on my box and it is definitely related to the RAM chips. I found them on ebay, replaced them - all the pixels are available again. In fact, finding the sockets for the RAM chips was the hardest part, as they are wider than normal ICs...
regards,
flip
-
Excellent points - especially the one about the game continuing. I hadn't considered that - there doesn't appear to be a loopback that halts the logic if the beam is cut... I guess the same goes for the timer issues. Problem with the tests is that I can't get past the title screen of the test cart. The first test (listed as #3 in the service manual) fails and I can't get to the next ones...
I had replaced a number of chips on the logic board hoping to resolve the issue, including the ROM. That's an EPROM, which tests fine in my programmer. The two ram chips were also replaced with new ones, though I realise that that doesn't rule out they could be faulty... Looks like I'll have to go back to the logic board to see whether anything weird is going on there, possibly in the DAC part...
Philip
-
Thanks for the reply. It's reproducible. When test #3 (linearity test) comes up, the screen goes blank. Oddly enough, some games play fine (Minestorm for example), while Berserk for example seems to experience the same problem. Pressing a button doesn't recover - only switching off or reset does.
The main voltages (-5, 5 and -13v) remain stable when the screen goes blank. I'm looking at the 555 and the two potentiometers (R525 and R526) there, but they are hard to reach... I'm pretty sure the problem is on the 'power' board rather than on the logic side...
Thanks for thinking along,
Philip
-
Hi,
I've been trying to fix a buzz-model Vectrex with an odd problem: with certain games, the beam seems to turn off. Annoyingly, the first test pattern on the test cart also does this. Other games runs perfectly normal. I've recapped the machine, but that hasn't solved the issue.
I am guessing the problem is in the Deflection Detection/Beam Limit circuit but before starting to swap random components, I'm wondering whether anyone has come across this - and how they've solved it?
Cheers,
Philip
-
Long time fan of Chip's Challenge, so I'd love to get a code as well - I've sent a friend request on steam (pmarien)
Cheers,
flip
-
Hi,
Just wanted to use my first post to praise the screens: I installed one on my Lynx II today, and it's more than worth it. The instructions that come with it are clear and to the point. If you're comfortable with a soldering iron, it installs in about an hour and the difference is to die for.
Hopefully, the same will become possible for model I !
flip
-
1
-
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
RCA Studio II GOLD MINE! An interview with the Studio 2 Production Manager!
in Classic Console Discussion
Posted · Edited by flip
I've found the source of the problem with the multicart on 'newer' Studio IIs. As indicated, my original Studio II is an earlier version. The PCB is identified (in the left bottom corner) by a number, ending in 'D'.
On newer systems, this is an 'E' at the end. To the right of this are two ICs which are used to select banks of the RAMs and ROMs. On the 'D' revision, these are a CD4011 (4 NAND gates) and a CD4013 (2 D-type flip-flops). On the 'E' revisions, they were replaced by a CD4001 (4 NOR gates) and a CD4042 (quad clocked D latch).
The older logic doesn't mix MRD and TPA signals to what is refered to as 'TPA Buffered' in ekeefe's excellent schematic: the CPU's TPA is simply inverted and used as the flip-flop clock signal. It is also directly fed to the cartridge slot. This is what it looks like in a logic analyser:
On newer models, the inverted TPA is fed into the 4042's clock before it's NOR'd with the MRD signal. But it's this mixed signal that is fed to the cartridge slot. As it is used as a clock signal for a 4042 latch on the cartridge, it messes up the addressing of the EPROM on the cartridge in some way.
If I feed the cartridge slot with the clean TPA signal, things work again! The problem is now that in its present form, the newer Studio II needs a small modification to get the TPA signal to the cart. Not ideal, as not everyone may feel comfortable with that and it probably affects most machines. I am not sure there's an easy way around this... It would probably need a change to the latching circuit on the multicart, but it's not obvious how at the moment. Suggestions, as always are welcome!
flip