SIO2

Looks more like a mock early prototype to me. I wouldn't sell something that shabby though. It was really only an experiment that I hoped might stimulate some thought about alternate cart designs. Cardboard just happened to be a quick and easy way to rough something out. Technically, no cartridge shell is required. The game pcb can still be inserted into a machine and played. Games without shells take up a lot less storage space. Shells make handling carts nicer though. Some of the boards have sharp edges and or sharp soldered pins. In addition to making the cart more comfortable to handle, it keeps a person from having to come in contact with the lead based solder. The shell also protects the game from damage and keeps it clean while helping to guide the game into the cartridge slot. Atari's cartridge shell design was excellent and I can see why a lot of pacmans get their shell robbed for home brew projects. I believe though that a satisfactory cartridge design could be made from simple cast or machined layers in sandwich fashion and that it could be done safely using more appropriate materials and allowing more head space for the heat that can potentially be generated by the integrated circuit to dissipate. Just curious but, does anyone happen to know what the metal shield on the game pcb that sits over the IC was for?

Nah, I never play that game anyhow. Seriously though during testing my cart did not get hot but this was just an experiment. Don't try making or using this cart. It seemed obvious to me that it isn't a real solution for the lack of new replacement shells and was just a for fun experiment but perhaps some people didn't see it that way. Again, don't try this at home.

My pacman was robbed of his shell. I couldn't just leave him homeless. I call it a cartwich.

Solved. I modded another 7800 mobo (REV A) and put the DevOs eprom in. So far I have dumped and uploaded and played 2600 frogger, 2600 space invaders and 7800 centipede using the same laptop PC, cable and 32k linear ram cart. So, there is a problem with the other 7800 mobo. The problem is not the missing 74LS02 timing circuit because the working REV A board doesn't have it either. Perhaps bad ram though the mobo rams were not getting hot. I'll have to work on that later. Right now, I am going to play centipede from ram cart.

I noticed that Eckhard's instructions with release two say that you could test a small upload without a ram cart and to use -w2000 switch. I tried uploading splat.bin with the -w2000 switch. I get a timeout error. If I upload splat.bin with -w1800 the transfer completes but the game does not run.

This 7800 that I am having the trouble with uploading does not have the 74LS02, cap 65 or R66. I understand that some people remove these to improve compatibility with 2600 games but this unit never had those parts installed. Would this have any impact on uploads?

I now have a DevOs .2 modified 7800. It seems to work to dump carts as I have dumped Space Invaders and the resulting .bin worked in the Stella emulator and also played on the DevOs 7800 when placed on a Harmony cart. However, when I try to upload to the DevOs system 32K ram cart with cap moved to factory position, it says the transfer was done but the game doesn't work. I am using a Windows 98SE laptop booted in dos mode for all transfers down and up. I have tried the version of 7800ctrl.exe included on Eckhard's website with release 2. I have also tried the 78ctrl38.exe version with the -c1 switch. No luck. Results have varied depending on what I tried to upload from black screen to vertical monochrome color bars to multicolor rolling patterns. My laptop parallel port options are ECP and standard bi-directional. I have tried both and it didn't seem to make a difference? I tried uploading a 2k game splatform 1.01 with switch -w1800 and it transferred but did not run. I tried uploading it with the ram cart in slot and without a ram cart inserted. Did not work either way. I assume no cart would be needed for this case? Is there a chance this 7800 has faulty internal ram? My goal is to be able to upload 7800 homebrews for testing on the real hardware. Any thoughts or advice on what I might try to make this work are greatly appreciated.

1,727 Frogger game 1A

32 on Game 1bb Freeway

Where did you toss them? Maybe I can do a video about digging them up. Lol.

Great work. I like it all.

376,300 NTSC

266,500 and 106,250 on first ship.

238,950 I made it to Earth and beyond. I started out trying to play on my NTSC XEGS with an Atarimax 8mbit flash cart. I tried the Fandal version and another version and neither would boot. I the tried the Polish VBXE fix XEX. It boots on XEGS but I got the asteroid bug two consecutive games plus the bonus round ship patterns were out of sequence. Then I remembered where I put my actual Parker Bros. Gyruss cart. The real cart worked perfectly on my XEGS. So the score posted is from an actual Gyruss cart on XEGS (NTSC).

9,050

1A 1,525 Dear mom and dad: time really flies here at frogger camp. Having a great time. Met a female that likes to ride on my log. Hope to take swimming lessons soon. If you come for visitors day, be careful as traffic is really bad and there are snakes and gators.

Too bad we all don't live forever. Five years is a significant chunk of a human lifetime. At least 1/20th if a person lives to 100 years old. Might be closer to 1/5 of the time I hope I have left to enjoy such things.

Interesting to know Best has those. I suppose they are NOS parts and not improved gears? If the replacements have the same failure rate, you might have to have friends and relatives order gears to get around the two sets per customer limit. 1020 is fun to watch work. I even used it once to print out program listings in 80 col. Kind of fun to have the little scrolls on my shelf.

I agree with the poster who said buy a box. It might be harder to find next time you need it. Besides, just imagine how many spit balls you can make from the perf strips.

Many many years ago I used a 1020. Mine had trouble with the tiny plastic gear on the drive motors slipping and splitting or splitting and slipping. You might check to see if the gear is intact on the motor that drives paper advance. As for pens, I had seen something on the web where a person drilled a tiny hole in the pen case and used a hypodermic needle to inject ink. I used to get pens and paper from radio shack because their cgp-115 printer used the same mechanism.

Thank you. That helped. According to the data sheet for the AS7C256-20PC SRAM and the pinout for the 7800 cartridge port, the cap should have remained in the factory position. I will have to move it back. The way this board is marked, I can see why someone was confused by the instructions.

I have one of these RAM carts that I did not build and can not test because I do not have a Dev Os modified system yet. I hope to have one in the near future. BTW is someone sellig the Dev Os. roms? I was reviewing the instructions for building a 32k ram cart (devcarts.pdf rev 14/2003) which says to "ensure that R1 and C2 are fitted." Comparing the RAM cart I have with an unmodified 7800 Cross Bow cart, it appears whoever built the RAM cart moved the cap from its default position to the C2 marker (see photo, RAM cart on top, Cross Bow on bottom). Which position should the cap be in for the RAM cart?

46,650

70,370 and 47,210 on first Jr. Pacman. I almost made it past the train but train keeps kicking my caboose.