Troubleshooting a kickstart switcher

[jman]

Hello,

I have a little problem installing an Alfadata KS switcher, this model, on a A2000 v6.2:
http://goo.gl/7rvCb

I also have found a brief manual:
http://www.storiepvtride.it/amiga/ks...ata_manual.pdf

Ok, so according to the manual I simply have to connect a cable to Gary, pin 5 and the other one to U300, that is the CIA, on pin 8 because I want to trigger the switch with the left mouse button.

So here's a quick and dirty test I did on the A2000:
http://www.storiepvtride.it/amiga/ks_switcher/

The issue is that upon startup I cannot operate at all the left mouse button, let alone perform any kind of switch.

I think this is a very trivial issue to solve, just a little bit out of grasp to me :-)

Thanks

[jman]

Just as test I've tried moving one end of the switcher from the CIA chip to Paula, pin 33 (= switch triggered by right mouse button) - and the result is the same, just stopped working the right mouse button.

[roy bates]

does the kickstart swicher work with only one rom in the socket? are you using a 3.1 kickstart with 1.3?

[Jope]

That the page you linked to had two differently working kick switchers depicted.

The one with the red and black clips has a 74F74 chip (dual flip flip) where your switcher has a 74LS04 (hex inverter).

The 74F74 switcher looks like it is a Utilities Unlimited switcher, not an Alfa Data.

The hex inverter style (the one you have) switches by shorting or opening the jumper. Connect a SPST switch there and drill a hole into your case.

The flip flop style is supposed to be connected to the Gary and CIA like you are trying to do.

The manual you linked to is identical to the one that was supplied with the Utilities Unlimited switcher, also it doesn't mention Alfa Data anywhere.

[jman]

Originally Posted by roy bates

does the kickstart swicher work with only one rom in the socket? are you using a 3.1 kickstart with 1.3?

Yes. If I switch the ROM chip on slot 1, boot is working.

Originally Posted by Jope

That the page you linked to had two differently working kick switchers depicted.

The one with the red and black clips has a 74F74 chip (dual flip flip) where your switcher has a 74LS04 (hex inverter).

The hex inverter style (the one you have) switches by shorting or opening the jumper. Connect a SPST switch there and drill a hole into your case.

The manual I've put is the one I was indicated, but I believe you saying could be the wrong one :-)
So basically you say that my KS is working attaching a switch like this one on both pins, right?

Thanks for your help, I'm not very skilled on the subject ;-)

[Jope]

Originally Posted by jman

The manual I've put is the one I was indicated, but I believe you saying could be the wrong one :-)

It is for the 7474 style switcher.

So basically you say that my KS is working attaching a switch like this one on both pins, right?

Yep, anything that connects the two pins when turned on, and disconnects them when turned off. :-)

[jman]

Originally Posted by Jope

Yep, anything that connects the two pins when turned on, and disconnects them when turned off. :-)

Hey, it's working, you were right :-)

I'm just curious about one thing: how could you tell my kickstart switcher work with a switch? Did you read the chip code and you're familiar with it?

Or it there a way to tell how a kickstart switch work by just looking at the PCB?

Thank you very much.

[Jope]

I looked at the pictures of the PCBs, compared them a bit (the 7404 switcher solder side picture is quite informative), read what was written on the chips, then dug out the datasheets for each chip and made my conclusion from the datasheets and the 7404 switcher pictures.

I also have experience with the Utilities Unlimited switcher, so I know for sure how that one works.

[chaos]

Sorry for re-opening this thread, but I have a similar switcher as was described by Jope (the Utilities Unlimited), but mine is apparently from Micronik (marking on the PCB are Micronik, LS, and 5050), but I couldn't find anything about it. The kickstart switcher has a 5-pin header with two jumpers and two wires for connecting to Gary & CIA. There's a 74LS74 IC on the board.

The switcher acts funny, if I boot the default ROM, everything is OK, but if I boot the alternate ROM by pressing LMB, if I press LMB again after that, the kickstart switches back to the first ROM, crashing the Amiga.

I traced the connections a bit, the jumpers are a little weird, as one is connected to the /BYTE input of the ROM, but just to one of the ROMs. The other is connected to some high address pin on the other ROM. (?)

The Amiga _RESET signal goes to 74LS74 CLK input, the left mouse button signal goes to 74LS74 D input. Both /SET and /RESET are tied to Vcc. Since this is just a simple D-type flip-flop, the Q output should be set only when the CLK signal has a low-to-high transition. I have no idea how the Q output is changed with CLK being high, just by changing D input.

Jope, did you by any chance see anything similar with your switcher? I have no idea what s going on, the only thing I can think of is a malfunctioned 74LS74 IC, but I honestly haven't yet seen any similar logic chip failing, especially not like that.

[Jope]

Can't say that I have. Mine always stays on the selected ROM until the next reboot. Are you sure you have the reset and mouse button wires the right way around? If so, then the chip might indeed be shot. :-)

[chaos]

I found a used 74HCT74 in my electronic "junkyard" and replaced the IC - it is working correctly now. Who would have thought? Thanks anyway!