Kroko

I think as long as you start at the beginning and double everything until the rom is full, you can use 2K,4K,8K,16K and 32K boards and they should work fine :-) At least I can't imagine why they shouldn't work ...

I will send the current commander source ASAP ! Should I make a document explaining the commands, or is the source ok ?

Currently Only Windows 2000 and Windows XP are supported. But if anybody is willing to port the commander to the Mac, I will make a description of how to talk to the cart ... I don't have a mac ...

1. Start the Krokodile Comander (Some Windows Software) 2. Click on the "Multicart" Tab 3. Select The Multicart Type and the Games that should be on the multicart 4. Press a button to create the ROM-File 5. Download that ROM to the Cartridge (another button) 6. DONE ! Is that easy enough ?

Well, the main problem is the prize. If you only order one, then its extremely expensive. The PCB and some of the chips on the design are much cheaper in quantities. I don't need lots of chips and pcbs for my hobby and if I order them, I have to be sure that they are sold sooner or later. An order of 25 is in the 2000$ region you know ... I will make a list of people who are interested. And If I have the feeling that 25 could be sold, they will be available (most likely in the AtariAge store if Albert agrees) I am going to make new ones as soon as there seems to be enough interest. In theory I can make a single device any time if you are willing to pay a prototype price

Hehe ... I think this might be a cool Option Me, too But I am not sure if I can offer a free Krokodile cart to the winner, because I am not a big company and the material is quite expensive ...

Sure, but you still have to make sure, that the identical vectors don't make trouble on the systems that made trouble with the different vectors

No, not Good. The First version worked on my cart, too. It worked though the vectors were not identical. I have no idea, why it makes problems on Thomas' device ... I think your binary still makes problems on his system ...

Ah ... you posted a ROM already. This one works without problems as well But now there are colors on my PAL TV ...

I have compiled your first source and tested it on my krokodile cart. For me it seems to start just normal in 100% of the cases. Maybe it would be a good idea to post the binary, then we are sure that everybody is testing the same thing. You only need to somehow put 1FF8 or 1FF9 on the adressbus. You should probably try a STA $1FF9. I would be interested if this changes something. The bus timing is differend while loading and storing AFAIK.

Prototype 2 doesn't need an extra adapter

The price is highly dependent on how many people are interested to get one, but I think it will be in the 99 Dollar region

In Superchip Mode you can use 128 Bytes of RAM (F8,F6 and F4) In FA Mode you have 256 Byte, in CV Mode you have 1 K and finally in 3E Mode you can use 32K RAM.

I am still working on the Krokodile Cartridge, and I think it is time for a little update now. I have changed a few things compared to the first design. One difference is, that it doesn't need an external power supply, when it is plugged into the 2600. In addition, it can now also be used as a Multicart. There are 4 different Multicart modes: Mode 1: 1K 2K or 4K (up to 127 Games) Mode 2: F8 Bankswitched (up to 63 Games) Mode 3: F6 Bankswitched (up to 31 Games) Mode 4: F4 Bankswitched (up to 15 games) It is possible to create custom MultiCart ROM-Images and download them to the device. The games can be selected with a menusystem that is part of the MultiCart image. And of course it supports standalone games. The downloading is done with a serial cable. Here is a summary of the current features: * 1K / 2K / 4K / Non Bankswitched Multicart (127 Games) * F8 / F8SC / F8 Multicart (63 Games) * F6 / F6SC / F6 Multicart (31 Games) * F4 / F4SC / F4 Multicart (15 Games) * 3F (up to 512K Rom) * 3E (up to 512K Rom and 32K Ram) * EF (Homestar) * FA * CV If we don't find lots of bugs during testing, I hope I can release it soon

One good document is "64doc" and I downloaded it at ftp://ftp.funet.fi/pub/cbm/documents/chipdata/64doc I also found some tables by searching google :-)

Just Brainstorming: You are in Bank 2 and want to switch to bank 1 when the processor is fetching the opcode from location FFF8, the bankswitching should take place more or less immediately. Depending on how the bankswitching logic is designed (what switching delay etc...), you switch before, during or after the fetch of the opcode. That means you could fetch a) the NOP from this bank (you fetch before the switch) b) the RTS from location FFF8 of the other bank (you already switched before the fetch) c) ? (i don't know what happens if you switch in the middle of the fetch) maybe you get a mix of RTS and NOP :-) So this code brings you to bank1, but you did not necessarily fetch the RTS. Can you try to replace your NOP with an RTS, so you can be sure that you fetch an RTS. I don't know how the emulators do the switching, but on real hardware you are only safe, if you have RTS two times. But now you have a second problem, that has to do with how a RTS is actually done by the microprocessor. Unfortunately the processor will not only fetch the RTS opcode, but will also do a dummy fetch of the NEXT byte which is at location FFF9 ! Now guess what happens :-) ... We are back in Bank 2 :-( A solution would be to put the RTS at FFF7. Then you would switch banks during the dummy fetch of the RTS (at least in theory :-) Here is what RTS does, step by step ( The PC+1 is the problem ...) +---------------+------------------+-----------------------+----------+ | Cycle | Address Bus | Data Bus |Read/Write| +---------------+------------------+-----------------------+----------+ | 1 | PBR,PC | Op Code | R | | 2 | PBR,PC+1 | Internal Operation | R | | 3 | PBR,PC+1 | Internal Operation | R | | 4 | 0,S+1 | New PCL-1 | R | | 5 | 0,S+2 | New PCH | R | | 6 | 0,S+2 | Internal Operation | R | | 1 | PBR,NewPC | New Op Code | R | +---------------+------------------+-----------------------+----------+ And lets have a look at the Bank 1 code which should bring us to bank 2: I don't really understand why the BNE $FFF9 is needed .. but lets assume the branch is taken and we jump to FFF9. Then you switch banks again before, during or after the fetch of what is at FFF9. Shouldn't there also be an RTS at FFF9 ? You don't get a FFF9 on the databus, before the processor is fetching the opcode from there. But if it does so, its important whats in that cell. So i would try an RTS at FFF9 in both banks. I hope I didn't misunderstand what you want to do there ....

I just tested it on my flash cart and didn't have any problems. I didn't even get a brown head ... but maybe thats because I didn't play it long enough ... Do the aliens eat trees ?

jmp $D8D8 jumps to $D8D8 jmp ($D8D8) jumps to $D8D8 (if you have $D8 in every cell) so the only problem would be if you get rubbish in case you switch, while the cpu is fetching the highbyte of the target, right ? But that is actually VERY unlikely .... Do you think it could be a good idea to watch databus bit 4 and prevent the menu switch, when it is not set ?

cuz we need $1X $3X $5X .... etc ... damn I wish I could edit my posts ....

Damn, you are right of course its bit 4 :-) i was just a bit confused ...

1st 2K bank in 2K mode and 1st 4K bank in 4K mode, right ? Should also work in 4K mode, shouldn't it ? You just have to fill 4K in 4K mode ... and put the menu in the second 4K bank ..... Until it reaches the instruction that switches to the menu bank, right ? (which is LDA $0801) The vectors have to point to your LDA $0801, where you switch to the menu code, right ? Ok, I see. You want to get 1,3,5,7,9,B,D,or F as the high byte of a jump. But would't that mean that Bit 0 has to be set ? Or am I missing something ....Wouldn't be funny if your jump target would be a ram adress or not adressing the rom .... What about indirect jumps ? Can you prevent indirect jumps to jump to ram ? Maybe only if the RAM location wich has the same address as the value of your opcode and the adress after contained a valid jump vector....Any ideas how to handle this ? Keep us informed. Even if it is not 100% safe, it may still work in most of the cases or fail only once per year .

Hmmm.. so far so good, but what if the cpu is just fetching the target adress of a jump when the "Back to Menu" button is pressed ? Or if it is in the middle of a fetch, then switching might mean the cpu gets just rubbish, or ?

Thats interesting How are you going to return to the menu ? Switching back to bank 0 will certainly just lead to a crash. Can you explain your theory a bit ?

The CPU is easy, because it has less pins than the other two :-) So the smallest of the 3 chips is the CPU. Here are some numbers that might help you: RIOT: CO 10750 TIA: CO 11903 CPU: CO 10745 You should be able to find these numbers on the chips in your VCS. Kroko

Sure, that sounds logical