Kroko
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Posts posted by Kroko
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Even though it seems to be possible .... would it be legal to sell Supercharger games on cart ? I don't think somebody would design such a cart, if selling it is not allowed. I guess it is too much effort just for one private cart. You can easily buy a supercharger for the prototyping costs.
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I am trying to write a cycle accurate 6502 hardware implementation in Verilog, and have a few things that make me go, "Hmmmm"....From what addresses will the 65C02 grab the address in the following cases:
If the instruction is "LDA ($ff,X)" and X=0, will the address for the load be taken from $00ff and $0100 or from $00ff and $0000?
Same question for "LDA ($ff),Y" and Y=??. Will the address be pulled from $00ff and $0100 or from $00ff and $0000?
Just trying to make this complete...
Thanks!
Zero page indexed addressing
Read instructions (LDA, LDX, LDY, EOR, AND, ORA, ADC, SBC, CMP, BIT,
LAX, NOP)
# address R/W description
--- --------- --- ------------------------------------------
1 PC R fetch opcode, increment PC
2 PC R fetch address, increment PC
3 address R read from address, add index register to it
4 address+I* R read from effective address
Notes: I denotes either index register (X or Y).
* The high byte of the effective address is always zero,
i.e. page boundary crossings are not handled.
# address R/W description
--- --------- --- ---------------------------------------------
1 PC R fetch opcode, increment PC
2 PC R fetch address, increment PC
3 address R read from address, add index register X to it
4 address+X* R read from effective address
5 address+X* W write the value back to effective address,
and do the operation on it
6 address+X* W write the new value to effective address
Note: * The high byte of the effective address is always zero,
i.e. page boundary crossings are not handled.
So I guess you always need to forget the highbyte in these adress modes. 
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But didn't Andrew Davie say that Kroko (or someone?) built a board for his Boulderdash game? Lemme see if I can find that post...Yes, but it is probably not cheap enough ... The clocked logic adds to the costs and it is using a CPLD. Maybe somebody is able to design something cheaper that is better for mass production :-)
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Note that my goal here is *NOT* to produce something like the KC/CC, but rather to produce something that would be cheap enough that the AA store could burn in Wormy IIIWhat do you think would be "cheap enough" ?
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I wonder why nearly all games use SEI, when the 6507 doesn't even have interrupts? Some games don't (look at Human Cannonball for instance.) I've tried removing this and the games work fine.It doesn't have the pins, but some programmers fear that they might occur, even if the pins are not there. I don't know if it is documented in which way the interrupt lines are wired inside the 6507. I think they do exist, but they are not connected. If they are not connected, they might internally be connected to a fixed voltage level or they might float. If they float, interrupts might happen. But I guess they 6507 designers made a good job and you don't have to fear that an interrupt will accidentaly occur. I am not sure, though
Thats why I would probably also use a little SEI to be 100% safe.
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That's the one I tried accessing.File Not Found.
Well it works 100% ok for me ....
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You need to use the official link:
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Here's an interesting discovery I found.the 16k multicart has some strange problems.
For example: Jr. Pac-Man works perfect as a single rom. But, it loads wrong as a multicart.
Other things I found: Midnight Magic actually runs a tad slower than the original. Yes I have the original to test it out. Works fine as a single rom but once again, as a multicart, it runs slower.
Anyone else run into problems like this?
Jr. Pac-Man needs extra RAM. Extra RAM is not supported in multicarts. Only plain F6. I really need to update the Krokodile Commander to prevent the download of unsupported ROMs to a multicart ...
Are you sure you download the same Midnight Magic ROM as single and multicart ?
The only possible difference is initialisation. In a multicart. RAM and Registers have
a defined startup value. If you download standalone, the RAM and Register content
is random. So yes, there might be some differences ...
Well, you can play whatever you like more
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Great Job
Thanks ! -
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Good Job ! I start to think that those companies only invented new BS schemes because there were patent issues with the common ones ?!
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I think some of these attachments might help you
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Thomas already converted both versions. PAL and NTSC
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Actually, depending on which bank is currently mapped in and which bank the current state of the databus would select, a STA WSYNC would trigger a bankswitch on a 3F cart. That's why the Tigervision games access the TIA through addresses $0040 to $007C.
Very interesting
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Please send Albert a PM if you want one. He will set you on the waiting list. My time is a bit short at the moment, so it may take a bit before new devices are finished. If you are on the waiting list, you will get one from the next batch
I currently can't give you an exact date, though -
As Kevin Horton's bankswitching guide says, 3F games react to accesses to all addresses between $0000 and $003F. But the switch will only happen when this access is followed by an access to an address between $1000 and $1FFF. Did your hardware handle that as well?Lets look at a simple "STA WSYNC"
1. we would access a memory location between $0000 and $003F , right ?
2. the next adress on the bus is from ROM space which has to be in the $1000 -$1FFF range, because we simply fetch the next opcode.
Would that mean that a STA WSYNC switches banks ? I doubt that :-)
Armin
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And I just realized that it obviously is just my private way to count the pins at the atari connector. But with the above picture you should be able to figure it out. Don't use the pin numbers, but the meanings of the pins :-)
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Just a clarification here: The meaning of the pins on the VCS connector is different from the meaning of the EEPROM pins. My picture above is only valid for the following meanings:
Top Row:
1(SGND) 2(VCC) 3(A8 ) 4(A9) 5(A11) 6(A10) 7(A12) 8(D7) 9(D6) 10(D5) 11(D4) 12(D3)
Bottom Row:
24(A7) 23(A6) 22(A5) 21(A4) 20(A3) 19 (A2) 18(A1) 17(A0) 16(D0) 15(D1) 14(D2) 13(GND)
Sorry if I confused you ....
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Don't know if you already have it, but I attached a document I found about arcadia bankswitching.
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I attached the pinout of a 2732. I don't think there are different versions.
The question is just: Is the chip you are looking at really a 2732, or is it a custom made ROM. If it is a custom ROM it may have a different pinout.
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The pinout on a cart edge connector, if you are lookig at it from the edge connector end with the label up, the top connectors are 13-24 from right to left, and the bottom would be 12-1, correct?The consoles female connector looks like this, if you look at it from above:
1 ..........12
24 .........13
So I would think that if you look at the cartridge as you described, then you would see pins 1 to 12 from right to left on the top side and pins 24 to 13 from right to left on the bottom side.
o well
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Krokodile Cartridge
in Atari 2600
Posted
Is it really always the last game, even if for example only 3 games are on the multicart ? Unfortunately I do not own a 7800. Maybe the 7800 starts up in a different way than the 2600. I would have to buy a 7800 and find out what the problem is. I have currently no idea, why it does not work or if and how it could be fixed.
Armin