BoingBoss wrote:
Hi Jope,
A computer engineer of your pedigree, who's owned and repaired every computer known to man probably knows that many computers can be reset by grounding the reset signal.
Yes, I already know this, but grounding the reset pin on the 68000 processor does not work on the Amiga 500 motherboard. The "reset circuitry" is part of an Amiga 500 keyboard, but is not on the Amiga 2000 keyboard. On the Amiga 2000 the "reset circuitry" is on the motherboard. So, in order to install an Amiga 500 board into a Tower case and then use an Amiga 2000 keyboard with that tower, you have to build the reset circuitry and hook it up to the reset button on the case. The "reset circuitry" board consists of two or three ICs and a few resisters and caps. I know that there are detailed instructions somewhere on the internet that explains how to build this reset board. That is what I need.
Heh, did you check that A500 reset link on Aminet you were given before?
YES! In reset2.iff, it *shorts _RESET to ground* .. There's a diode too, but that's just for added safety, because in the example it's connected to the keyboard.. The instructions are for a bit more than a simple reset switch, but the basic idea behind it is the same.
- Do you know what the A500 keyboard does when you hit C-A-A?
- It grounds the separate _RESET line that it has, that doesn't exist on normal A2000 keyboards.
The reset circuitry you describe is needed if you want a *keyboard reset* on an A500 with a *big box keyboad*. The A2000 keyboard indeed doesn't have a separate _RESET line, so reset needs to be separately decoded because the signal is sent over the data and clk lines, not via a direct connection to _RESET.
But! You didn't want a keyboard reset circuit! I'd have given you one if you'd asked for that. You wanted to use the reset button of your tower and that's what you got.. Also the Aminet link describes a similar scenario. My instructions omitted the diode, but like I said, it isn't 100% necessary.
LOL indeed. :-(
Some A2000 keyboards can be modified to give the _RESET signal:
Check out Q1 on an A500 kbd and see if your A2000 kbd is missing that transistor.. If you solder it in (mind the orientation), the NC line of the A2000 keyboard cable should turn into _RESET and the a big box reset feature will be disabled..
I've succesfully done that mod in reverse - IE removing the transistor from A500 kbds to be able to reset big box Amigas. (with Q1 in place, the A500 kbd only draws _RESET low for a while, which the big box machines will never see, since that line doesn't go to the kbd socket)
Now you must also be aware, that there are several different revisions of big box Amiga keyboard, so you might not be able to find a missing Q1 in your particular unit.. Then it's just tough beans, but it doesn't make what I said wrong.. Then it's just not possible with your setup!
I do realise I should not have been so aggressive before, but "I wouldn't have known what I'm saying" even if I'd have written in a normal tone. Nice to always "lose" in the eyes of your debate partner, isn't it?
I did have a long break from replying to you. I guess I should have continued, since my knowledge is just not appreciated. I don't have a big name in the Amiga circles, but I do have over a decade of actual hands-on Amiga experience, modifying HW, reading the schematics, using the damn OS, etc.
I'm not wrong _that_ often, but I do debate my point if I don't get proper reasoning in return.. I will admit my failure if I'm properly shown where I was wrong, but I haven't seen that from you, as far as I can remember. In this thread you were talking about apples in the beginning and oranges above .. try being the opponent with the debate's target veering left and right and changing from red to green halfway along the way?
So.. I won't reply to you any more, unless someone (other than you) proves me wrong and shows me why.. Then I'll post my admittal of defeat, but so far I am undaunted.
Have a nice rest of your life, and I hope you some day understand why many people don't like your way of participating on the forums here.. Part of this fight is my fault, but I'm very biased thanks to my past experiences with fighting over moot points with you. :-(
Sorry to everyone I've offended with my bad behaviour, I'll go and sprinkle dust on myself now.
