Kroko

On the Krokodile Cart ROM and RAM are different chips. So to be compatible, the mode must be such, that writing 0-31 to location $003E selects RAM Bank 0 to 31 (no matter were it physically is on your RAM chip) These banks have a size of 1K. 0-239 to location $003F selects ROM Bank 0 to 239 (whereever it may be in your RAM chip) These banks have a size of 2K This example is for an upper limit of 32K RAM (32RAM Banks) For 64K RAM it would look like this 0-63 (RAM) 0-223 (ROM) It is necessary that each banknumber starts at zero, because it is implemented that way. CURRENTLY the Ram banks are mirrored if you go upwards. So if you select RAM bank 32 you end in RAM bank 0 and so on. But we really should keep higher numbers for higher banks in the future if this mode is extended to say 64 K RAM ... Wouldn't it be possible to just activate a higher memory area of your RAM chip if a write to 3E takes place and enable CV access for that area ? I think we should try to agree on an upper limit for RAM so that you can decide from which point upward you want to map in your RAM banks. And you need to choose a starting adress from which it is easy to map the RAM banks ... I still think it makes sense to wait for the first project that is done with it and let Andrew decide how much RAM/ROM makes sense for that mode. I don't hink we get problems with the fixed bank. Just let everything as it is in 3F switching. The vectors are in the last 2k of the ROM. If we keep it such, then I don't expect problems. How your hardware is dealing with the fact, that the fixed 2K bank is always the last bank of the ROM is not so important. The KK does it by always using the physical bank 255 as the fixed bank. So if you use a smaller ROM the last 2K have to be copied to that location. I hope this was not too confusing Armin

Please don't forget that 3E could be expanded in the future such that we have 256K of additional RAM available. The only reason why there are currently only 32 is the size of my RAM chip. but the concept is such that you can have 256 ROM banks and 256 RAM banks. My suggestion is, we wait until "something" is available for 3E and then agree on how 3E should be expanded in the future. Can't think of any application that could really need 256K RAM But before you make a 3E version for the CC2, we should ask people how much RAM they COULD want to use in the future to find the best compromise between ROM and RAM size.

There are no secrets! 512K 3F switching is like "normal" 3F switching. The only difference is, that the fixed bank is always at the highest 2K of the 512K ROM. Apart from that, just switch in the selected bank. The download software has to make sure to copy the highest 2K of each 3F ROM to the last 2K of the 512K adress space of the cart. 3E is just an extension to 3F. If works exactly like 3F, the only difference is, that a write to 3E switches out the current ROM bank and switches in one of 32 RAM banks. RAM access works like with Commavid RAM. Read port is lower 1K and write port is upper 1K. So you get 512K Rom and 32K aditional RAM

Hi ! are you interested in what is going on inside the CPU ? 1 fetch opcode, increment PC 2 fetch low byte of address, increment PC 3 fetch high byte of address, increment PC 4 read from effective address 5 write the value back to effective address and do the operation on it 6 write the new value to effective address

Thomas already converted Gyruss

No, just name them as you like. The Krokodile Commander idetifies ROMs by their content and not by their name. You can use any valid file-path.

In principle there is no limit. The only challenge is to define a good way to access it from your code ... I don't hink that this is true. The amount of power that is drawn from the console is not depending on the RAM size, but on the power consumtion of the used chip(s). If the RAM chip is active, the ROM chip is in standby and consumes less power. Todays RAMs do not draw a lot of power ....

3F (Tigervision) bankswitching requires quite some logic ...

The cartridge was not changed. You are right, it was only an update of the windows software.

NO ! Everything you do with a flash eprom or a flash perom is done at its normal supply voltage (e.g. 5V) I didn't come across devices which require a special programming voltage. Read access is identical to EEPROMs. Writing is a bit more complicated. Flash memory is sector based and you can only write a complete sector. Different devices have different sector sizes. AM29F040 has a sector size of 64K. That means you can't program less than 64 K at once. And you have to erase each sector before you can overwrite it. That could be a problem for you AT29C040 has a sector size of 256 bytes and you can just overwrite a sector without erasing it. That is why I have chosen this one for my device. There may be lots of other devices which all have different characteristics. You really have to look inside the datasheet to make a decision. Writing a sector is not really simple. Each device has its own "protocol" to write a sector. In some devices you have some timing constraints, which means you have to finish the sector programming within a certain time limit. The lines that have to be controlled during a sector write are OE,WE and CE. The datasheet will tell you exactly how you have to set these lines to make a successful write

As Albert said, I was investigating if it is possible to mix different cartridge sizes on the multicarts. There is some good news and some bad news: 1K,2K and 4K games can be loaded into ANY multicart. But you can only choose one bankswitching mode for the multicart. That means: if you compile a non switched multicart, you can select 1K,2K and 4K ROMs if you compile a F8 switched multicart, you can select 1K,2K,4K and 8K ROMs if you compile a F6 switched multicart, you can select 1K,2K,4K and 16K ROMs if you compile a F4 switched multicart, you can select 1K,2K,4K and 32K ROMs But you can NOT mix 8K,16K and 32K ROMs

Sorry, the cart is in already in production. It is too late now to make changes to the design. I think 127 games on one multicart image should be ok. And you only need one minute to exchange the complete 512K image with a second multicart image that can hold another 127 games

The Krokodile Commander can verify, if your download was successful. It reads the content of the cart and compares it to the currently selected binary. But why would you want to store what you just downloaded ? You don't want to use the Krokodile Cart as a 512K memory stick, right ?

Glad to hear that ! And good luck

If it doesn't have the correct size you can not select it, because the file selection dialog simply doesn't show it. Hmm... I think in the next version I will look up the bankswitching mode of a selected ROM in the database and display a warning if the mode does not fit. Maybe it will be a little later, also because shipping is slow during christmas time. But I am sure it will be in January

The Krokodile Commander comes with a database that contains the bankswitching methods for all known ROMs. If you select a ROM, the bankswitching method is displayed. If you compile a multicart, the Krokodile Commander only lets you select ROMs that have the correct size. So ... if you compile a non switched multicart, you can select 1K,2K and 4K ROMs if you compile a F8 switched multicart, you can select 1K,2K,4K and 8K ROMs if you compile a F6 switched multicart, you can select 1K,2K,4K and 16K ROMs if you compile a F4 switched multicart, you can select 1K,2K,4K and 32K ROMs The Commander does currently not check the bankswitching mode, only the size. So in theory you could select an 8K superchip ROM into an F8 multicart. But this game wouldn't work then. If you think the Commander should check the mode too, then I can easily implement it :-)

Hi Vern ! I am not sure, but I would say yes. In theory anything above 2.4 V should be high. I only fear that a 3.3V design is less noise tolerant than a 5V design.

There are so many good labels already that it will be a very hard decision... poor me ...

I think the cuttle cart plays more games. Differences are: * KC is a multicart CC is not * KC will be available CC is no more (or are you selling yours ?) * KC downloads games much faster * KC plays 3F games up to 512K CC up to (damn i don't know but less than 512K) * KC plays EF , CC does not (=> Homestar RPG) * CC plays E0,E7,FE and Starpath KC does not (and maybe another bs mode I forgot) They are just a bit different :-) Kroko.

Hmmm.... 50 normal starts in a row with the latest version.

I still think its a problem that only occurs at startup. A wrong initialisation of something. I don't think the bankswitching itself has a problem, or it would crash all the time. So its most likely that some timing issues of the console or the cratridge that can sometimes happen at startup are the problem. I think using the same vectors in both banks (like described above) is something that could help, in case the VCS is fetching the reset vector from different banks during startup of the cartridge. But why should that lead to problems that occur only 5% of the time during startup ?

hm ... not really but could you try to make a little delay loop before you do the first bankswitching ? Give the console and the cartridge a little time before you do the first bankswitch after startup.

The desing is finished. Just need to wait for the results from the final tests. I think it will be available very soon after we have a nice label for it.

Well, i can't find any problems. All 3 versions work just fine on my cart. I switched on and off about 25 times for each version and they always start fine ... Can you explain a bit more detailed what happens on your device ? Kroko

Can you post a binary ?