e5frog

As I posted in the "Fairchild Channel F Fan Page" Facebook group ( https://www.facebook.com/groups/1180282045468082/?ref=group_header ) I have tested eight #4 carts, earliest (1377) and last ones I have (7839). Works the same, you get to the end of the sequence but no message and any keypress after that resets. I'll try the rest of them as well but I don't have any high hopes. The code is fine but the environment it's in doesn't let it execute properly. It would have (it does) worked just fine in a development cartridge with eproms and a memory interface.

I succeeded in composite modding my Luxor VES, I think the birds-nest-prototype-pcb-thingy I made first was wired wrong, potentiometer wasn't working as it was supposed to. But the small ones I ordered from Aisler - no problems. Forgot to buy those expensive SMD potentiometers though, so this one has legs. Had a pretty good image with my proper "75 Ohm F-connector with adapters"-cable but waves in the image and distorsion on the white zeroes. Completely gone on the composite, nice clear image, like you took a cleaner and wiped all the interference away. It's of course not emulator sharp, it still has the normal composite video trades, checkerboard flicker along the sides etc.

Seems to me they usually start way too high and then lower until they get sold - some merchants keep the same prices over and over again but I guess it doesn't cost them anything. If we all offer around $10, I bet they'll lower the price... I'll offer $9 now. EDIT: $9 offered. BTW, no I've already got those carts, chances are boxes of them will pop up, like some that are still available on eBay at rocket high prices. #17 Zircon release, white box IIRC.

It's just a theory about the Data Counter but it seems the condition to jump to plotting the text doesn't happen on the real cartridge and it doesn't reset until the series is written in and a key after that is punched. If it has rolled over to $0000 instead it expects $70, which you can't feed it since buttons only affect the lower nibble. Upper nibble isn't even fully used - and even if you could insert all bit patterns you'd go through the entire BIOS and cartridge again without being able to get that roll over. As the Data Counter is inside the chip there's not really a way to check it to see what happens or manipulate it. I guess if he had checked the lower byte for $00 instead it would have solved such a problem but as a programmer it's quite likely he didn't know all the details about the hardware - or they changed it. Speculating further, Mr Glass probably put Easter Eggs in everything he wrote. Brad Reid-Selth wrote something about being vain in his youth, perhaps Mr Glass got over such "foolish" things later on in life. Personally I feel it's a nice thing to sign your work of art. @RT-55J I read the text and I'm not sure why it's embarrassing - because we haven't been able to trigger it from an original cart? It's true the ROMC control signal was most likely a cost reducing measure. I suspect Fairchild already had a platform for 40 pin IC:s and wanted to use that so they divided their CPU system into several chips (you needed at least two at the start) with ROMC to sync the parts. Pretty clever IMHO. As far as I understand they made their CPU before the introduction of the Fairchild Video Entertainment System so I wouldn't say they used the method to save pins in the cart, they used it to save pins on the chips themselves, number of cart pins was just. Yes, the Easter Egg would most likely be accessible on a development cart, as these have "plain" ROMs and a memory interface and the memory interface has a Data Counter that covers $0000-$FFFF. Yes indeed, the Easter Egg became free!

Nice find, nice to see you're here. I have a dumper and 11 #4 carts/loose pcb:s. They all dump the same, same data that works when in an eprom/flashrom connected to a memory interface circuit. I can probably take the time and try all of the originals in case there's a difference in the chip construction. Sean have decapped a few chips, maybe it's possible to find the data counter and check the number of bits. There's perhaps no reason to have a counter that goes past the available memory size. The memory interface allows the entire 16-bit range. Doesn't really matter though, the code is there... and it was an exciting find.

Still no luck with an original cart, I'm not sure data counter in the PSU(s) rolls over to $1000, perhaps they just used the 12 bits that was needed. I was following the example and noticed #15 seem to have a complete alphabet (4x5 font) but as far as I know it only spells "MEMORY-MATCH", 10 different letters? You can play the game with numbers or symbols, symbols version doesn't use letters. So... would they stuff the entire alphabet in there just for fun? But then again, #18 is full of letters and it's not easy to spot anything in that one... there are so many ways to hide away Easter Eggs. Seems if Michael K Glass programmed them, his name is somewhere in it.

This "Drag files here to attach" works, most of the times. If you have written a bunch of text, drop a file and it instead of getting attached - the browser opens the image file... and you try to use the "back" button... and see your text is gone. That's annoying. It's possible to plot en entire screen in about 1.2s, so 2500 pixels in 0.5s, a pixel plot cycle in multiblit is 24 cycles, that's from the added delay start until you're back on the delay start routine. Perhaps going for just dots would save some resources, if you could draw just two pixels on each side, not that it would look as nice. Here's the image I tried posting. Lines over track could scroll to make it feel more like moving (max two pixel plots in palette column(s)).

Got it showing from the Multi-Cart, press a key, wait a second and repeat.

Missed this one, now following Kurt... I had the same idea after seeing Antarctic Adventure for the NES, thinking it might be possible on the Channel F. What if you just draw lines and not solid green areas. If you want something to work on all consoles the Luxor V.E.S. sets the limit, it runs at 2MHz and shuffles code faster than the other machines, if delay is long enough for it it will work on the other machines as well. No need to limit yourself to the registers, you have configured RAM (unfortunately) in MESS/MAME $2800-$2FFF, adding RAM on a real cartridge "anywhere" is also possible. Of course it would be impressive to keep to the common specs, I'm impressed with what atari2600land has made.

Past free edit time... So, I tried my patched version (press button 1 only) and that worked, you can just hold button 1 for about 33 seconds (on a 2MHz console). So question is if something works differently on the real cartridge. A second between keypresses should be a long enough wait IMHO. I just stuffed 32 copies in a row on an eprom hooked to a SMI. One official difference between the SMI and a PSU is that the former has 2 data counters, which could explain the use of H and Q in the code - address could just have been backed up in DC1. Maybe something happens when the PSU(s) data counter rolls over, maybe it doesn't turn to $1000 but $0000 instead...? ... if so, perhaps it works as it was meant to on the Multi-Cart...

I can probably set up accounts somehow, "back in the day" only me and Tim were adding stuff, don't know how at the moment... I see how it can be difficult, things are spread around a bit and perhaps not a good introduction. The package was downloadable before site crashed when server was at Tim's place. I have tried to patch it up since then but IIRC I didn't have any backup of the C64 Defender of The Crown image showing program. I'll see if I can put something together, made some updates to the page for now. When converting an image with Kurt Woloch's converter you get both the palette data and the multicolor image data. http://channelf.se/veswiki/index.php?title=For_full_screen Note however that it only covers the full screen seen in emulation, a well adjusted TV in combination with some consoles will show one or more pixel lines in one or more positions. To be sure you have everything covered I recommend 108x64pixels, starting at real position (0,0). Some routines add 4 to coordinates to make (0,0) the top left corner in the emulated window, which slows things down among other things. Likewise a user's TV image can be "zoomed" in and off center in any direction so you don't want to place any important details along any edge. The graphics converter I wrote handles blit or multiBlit graphics, you unfortunately don't get a palette, maybe that's something I should add for widths larger than 101... http://channelf.se/veswiki/index.php?title=Graphics_converter If you're really really set on making an image by drawing the colors separately you need to separate them in a drawing program, run them through my converter (or some other way). MultiBlit version is faster though.

Has anyone managed to show the Easter Egg on a real machine? I have tried it on a Channel F II, ITT Tele-Match and a Luxor V.E.S. when the last button is pressed nothing happens, no resets happens in the sequence so it should still be in the loop.

Wow - how cool!! Did such things on the Amiga a few times, have never considered it for Channel F data. Did he do anything else we can look closer on? Maybe all roms should be re-examined. The ROM-disassembly in the Wiki has only be run through a disassembler and hasn't been checked or commented. Shouldn't be too hard to find the right spot, now that we know where to look. Here's the last data in the rom - which means he had over 188 bytes free in the ROM before adding the Easter Egg. 000007D0 04 08 04 02 08 02 01 02 08 01 04 04 02 04 01 08 ................ 000007E0 04 02 01 08 02 04 01 08 04 02 02 01 04 02 04 08 ................ 000007F0 02 04 04 08 01 01 01 02 02 04 04 02 08 08 08 04 ................ Here's the button data: %00000001 button 1 (1) %00000010 button 2 (2) %00000100 button 3 (4) %00001000 button 4 (8) Which turns into these button presses (as per description in the article): 343 242 124 133 231 432 142 314 322 132 342 334 111 223 324 443 Perhaps it's musical notes... I wonder if there's a time constraint... probably. EDIT: I checked the disassembly and added some comments. http://channelf.se/veswiki/index.php?title=Disassembly:Videocart_4 Quick patch: It's a lot easier if you only have to press 1 (after first pressing 3) 04_press3then11111etc.bin

I guess you haven't seen this one.

Yes, it's PAL, I'm guessing I haven't found a place with the proper level. In my earliest first attempts I isolated the signals from the RF modulator, adding in the chroma after the amplifier helped getting a color image then but the signal was weak and dark.

Yes, it worked very well on the Channel F II, but not on the Luxor V.E.S. Just got a B/W and rolling image there. Will try bypassing chroma and add it in after.

Cool, any documentation left? Brad Reid might be possible to locate, I was in contact with him a few years ago after mailing all Brad Reid in the US I could find an email address for - and it worked.

A friend has a similar problem with hot bridge and rectifier. He has swapped diodes and rectifier without success. Must be a short somewhere... Not much to do but to start checking IC:s (desolder). Measure current and unplug the socketed chips first I guess. Caps can short, little brown disc type as well, even if it's unusual.

Looks great apart from the stripes. So when E3 has 0 out it's fine but the others cause interference? I guess if interference is green and red there would be none when they're off... I had some ideas about s-video on my first version Luxor, couldn't get more than an inverted black/white rolling an image with the amplifier that works great with Channel F II, SABA Videoplay 2 as well as two first version Fairchild NTSC boards (though they had a lot of color bleed - on the TV I used anyway). S-video would be the best, if you don't have s-video input it's easy to get composite with an adapter or make one yourself with a small capacitor. When I installed the Longhorn s-video mod in my Vader (A2600), there was a composite video out option as well but when using an adapter on the S-video output the image was better. BTW have you found any errors in the schematic, sometimes changes are made and schematics not updated.

Any decision about hole 14 yet?

You could control something from software with the free bits, either in or out - or both.

Checked inventory, I have five cartridges left to offer in this batch, then I'll need to spend a month or three before getting parts for a new batch. So if you don't like waiting, this is the best time to get one as I'll probably finish soldering the current ones today before cleaning out cartridge shells etc. EDIT: Left in the batch is #179-183, the boards for 179, 180 and 181 are already done - no waiting time there.

If you should come up with anything there are unused ports that could be used to control things. Port 0 has bit 4 and 7 not connected and when not reading the controller there's also bit 7 on port 4. What about the 7445/74145 with all the colors marked out, nothing connected to bit 0,1 and 4.

How's this going?

Looks quite glitchy anyway, the 9xxx is Fairchild's own branded IC:s IIRC.