Witch way Update???

Centallica · Post by **Centallica** » Wed Jun 22, 2005 6:50 am

Mayhem wrote:
Centallica wrote:I won my Zorgon's Kingdom (re: past posting topic) with The Canadian Tire Compilation in the batch too off of Ebay today btw
I was actually going to bid on that, and didn't in the end. So consider yourself "lucky"

I think you saw a few currently up on Ebay that you have your eyes on more

Brian

KilrPilr · Post by **KilrPilr** » Tue Oct 18, 2005 11:11 am

Hmmm, Sorry guys. I dont know how I missed this post. I just discovered it while trying to find mayhems cart list link.

Anyway I havent been successfull in dumping the witch way cart yet. I opened it up and it turns out its a epoxy blob and not an eprom. I made a device sort of like what 6502dude described but It isnt working so far. What I did was take a cart port connector from a hacked vic mobo and then hook up the leads to a 24 pin eprom socket so that i could plug the cart into the adapter and read it off the eprommer but I think I may have wired something wrong. Im not sure. Maybe 6502dude could send me a pinout of such a device and I could try rewiring it.

Heres a mini mini review:

It is a donkey kong esque game where you start off in a big black cauldron with the damsel in distress at the bottom of the screen. Your mission is to get to the top where the water tap is, to turn it on and put out the fire before the damsel gets cooked! Look out for rolling rocks (possibly hot coals) and flying witches as you are messing with her supper.

I have made it to level 2 and it is different from level one but this is as far as ive played it so far.

Leo

vic user · Post by **vic user** » Tue Oct 18, 2005 11:16 am

Sounds like a cool game.

And just in time for Halloween!

chris

carlsson · Post by **carlsson** » Tue Oct 18, 2005 12:48 pm

Hmm, maybe the easiest cartridge dumping utility would be a plain VIC-20 with a modified Kernal ROM, one that will never attempt to autostart a cartridge in block 5. Instead it would always boot into Basic, and you could safely PEEK and save the data onto a secondary device.

Since first revisions VICs have their ROMs socketed, isn't that a piece of cake to hack the Kernal ROM, burn an EPROM and install instead of the real one? I suppose one could even put a small circuit board with an external switch on top, depending whether you wish to autostart cartridges or not.

Schema · Post by **Schema** » Tue Oct 18, 2005 12:57 pm

Or, use an expander with switchable slots. Plug the cartridge in but turn the expansion slot off. Turn on the VIC, then turn on the slot *after* the READY. prompt appears. Then PEEK away.

carlsson · Post by **carlsson** » Tue Oct 18, 2005 1:01 pm

Yep, I do something like that myself, but some people feel it is not safe to switch cartridge on the bus when the computer is on. Actually, I have a non-switchable expander, insert my memory expansion in the first slot and the other cartridge behind. The memory expansion is configured to RAM in block 5, and while the VIC is on, I toggle that switch and the cartridge ROM behind will shine through. Maybe it is not 100% safe.

Schema · Post by **Schema** » Tue Oct 18, 2005 1:20 pm

carlsson wrote:Yep, I do something like that myself, but some people feel it is not safe to switch cartridge on the bus when the computer is on.

I'm not sure why that is, since switching signals on and off is all the VIC itself does. Maybe Leeeeeeeeee can explain?

I know plugging a cartridge in with the power on is much riskier, because there is the possibility of getting it crooked and shorting two pins.

configured to RAM in block 5, and while the VIC is on, I toggle that switch and the cartridge ROM behind will shine through. Maybe it is not 100% safe.

Well, it has to be safer than this:

KilrPilr wrote:I made a device sort of like what 6502dude described but It isnt working so far. What I did was take a cart port connector from a hacked vic mobo and then hook up the leads to a 24 pin eprom socket so that i could plug the cart into the adapter and read it off the eprommer but I think I may have wired something wrong

Schema · Post by **Schema** » Tue Oct 18, 2005 1:20 pm

(double post)

KilrPilr · Post by **KilrPilr** » Tue Oct 18, 2005 1:53 pm

Well it wouldnt be bad if I had the wiring right the first time. Im hoping with this device that I can dump any cartridge without the need for plugging it into the vic. Would be cool but I need to work out the kinks. BTW, Can one of you geniuses tell me the exact commands needed to read the cart once i get to basic with the cart plugged in?

Leo

Leeeeee · Post by **Leeeeee** » Tue Oct 18, 2005 2:00 pm

carlsson wrote:Yep, I do something like that myself, but some people feel it is not safe to switch cartridge on the bus when the computer is on.

I'm not sure why that is, since switching signals on and off is all the VIC itself does. Maybe Leeeeeeeeee can explain?

Nothing to explain, switching carts on and off like this with the Vic on poses absolutely no danger.

I know plugging a cartridge in with the power on is much riskier, because there is the possibility of getting it crooked and shorting two pins.

The problem with plugging a cartridge in with the power on is the minimum and maximum safe voltages on the pins of chips in the cart. Most chips quote the max/min as volts above Vcc or below GND with some margins as little as a volt or less.

Now when you plug a cart in some pins will connect before others so imagine what happens if the GND connects and then the active address and data lines connect. With a max voltage of (say) Vcc+1v any line that's high will be more than this in the cart chip and may cause latch up[1] within the chip, this can lead to destructive current flow in the chip when the Vcc connects. The same can happen if Vcc connects first, any address data lines that are at GND will effectively be at -Vcc volts at the cart chip pins.

The way round this is to ensure that the power is connected before the signal lines and this is what is done in PCMCIA sockets that makes PCMCIA devices hot plug. If you look at a PCMCIA socket the power pins are visibly longer.

carlsson wrote:configured to RAM in block 5, and while the VIC is on, I toggle that switch and the cartridge ROM behind will shine through. Maybe it is not 100% safe.

It is 100% safe

Lee.

[1] When you make an IC you not only make the transistirs you want you also make lots of 'phantom' or 'parasitic' transistors you don't want. There is no way round this, shit happens, but you can ensure that within specified limits all these 'phantom' transistors are turned off and don't affect the operation of the wanted transistors. Outside these limits, e.g. when inputs go beyond safe max or min voltages, these transistors can turn on giving the supply current new, exiting and often destructive paths to follow. The only way to recover from latch up is to remove the supply and wait for the current to diminish to zero before re-powering.

carlsson · Post by **carlsson** » Tue Oct 18, 2005 2:57 pm

Phew!

This ML program, which could be placed most anywhere in memory, will access the Kernal routines to save a memory block to a device.

10 DATA 169,2,162,8,168,32,186,255,173,255,31,162,0,160,30,32,189,255
15 DATA 169,160,133,252,162,0,134,251,169,251,160,192,32,216,255,96
20 FORI=0 TO 33:READ B:POKE 673+I,B:NEXT

It is hard coded to save a memory block from $A000 to $C000 to device 8 (disk), but you can decide the file name yourself, assuming the video matrix is located at 7680 like an unexpanded machine:

Clear screen, and in SHIFTED LETTERS type in the name of the file in the upper left corner. Then POKE 8191 with the length of the file name. Use SYS 673 to execute the program.

If Witch Way is a 16K game, which I doubt if the same title was available on tape for unexpanded VIC (??), you would need to modify the program slightly before running it the second time:

POKE 692,96:POKE 702,128

Or the complete list again:

10 DATA 169,2,162,8,168,32,186,255,173,255,31,162,0,160,30,32,189,255
15 DATA 169,96,133,252,162,0,134,251,169,251,160,128,32,216,255,96
20 FORI=0 TO 33:READ B:POKE 673+I,B:NEXT

KilrPilr · Post by **KilrPilr** » Tue Oct 18, 2005 3:08 pm

Thanks Anders, ill give it a try

carlsson · Post by **carlsson** » Tue Oct 18, 2005 3:10 pm

Oops, I found a small bug, but I corrected my previous message, so please reload the page before typing in the program.

KilrPilr · Post by **KilrPilr** » Tue Oct 18, 2005 4:03 pm

Well that prog doesnt seem to work. i started the vic with the cart on an expansion board. I flipped a switch so that the vic starts then i flip it back after to the position I know the cart will work on if I was to reset the vic. I load your program from disk and type sys673 and it just clears the screen and says ready. Nothing happens to the disk drive.

Leo

Centallica · Post by **Centallica** » Tue Oct 18, 2005 8:59 pm

KilrPilr wrote:Heres a mini mini review:

It is a donkey kong esque game where you start off in a big black cauldron with the damsel in distress at the bottom of the screen. Your mission is to get to the top where the water tap is, to turn it on and put out the fire before the damsel gets cooked! Look out for rolling rocks (possibly hot coals) and flying witches as you are messing with her supper.

I have made it to level 2 and it is different from level one but this is as far as ive played it so far.

Leo

Thanks for the mini-review Leo! Sounds like a cool game...hope to run across a copy in cart or tape form some day

Brian