How to make a level 7 interrupt button for a1200?

[spotUP]

Hi!

I have an A1200/Blizzard 1260, and I want to install a level7 interrupt button.
Is there any guide for this somewhere?
I know how to handle a soldering iron, but I am not very good with electronic theoretics.

Could anyone point me to a guide or write a small step by step guide here?

Do I HAVE to solder on the 1260 card or can I solder on the A1200? I'd rather not touch the Blizzard.

[Zetr0]

hmmm

you could use a bus request signal, but then i am lost as to what data you would send.

/me ponders

[spotUP]

No one?
Someone MUST have done this?

[cosmicfrog]

remember soldering to 2 pads next 2 pcmia port on my a1200 for a reset button
but don`t know it it was a level 7 reset think it just did a warm reboot

[Toni Wilen]

Quick schematics (1D) check does not show any easy points.

Possible not-too-difficult position is termination resistors R953A, R953B and R953C (other side connects to /IPL0-2 and other side to +5v). In theory pulling all 3 lines down should trigger level 7 interrupt. Note that I have no idea about resistor(pack) location..

WARNING: Check and double check that lines are correct, they should connect to Paula's and 68EC020's interrupt pins. (schematics may not be 100% correct)

I probably try to do A1200 level 7 interrupt button after CDTV is finished.

[demoniac]

IIRC, HRTMon manual had a quick blurb on making one. Can't remember what model as it has been years since I've read it.

[Psygore]

Here the schematics from Thrill Kill package. Check the doc to install this button on A500/A2000.

[Toni Wilen]

A500/A2000 level 7 button is extremely easy to do. No surface mount components.

A1200 isn't so easy..

[frost242]

spoUP: I think you can solder on the A1200, just at the beginning of the edge connector... I'm also planning to add such a button on my own 1200, I'll post here when it's done.

[spotUP]

"spoUP: I think you can solder on the A1200, just at the beginning of the edge connector... I'm also planning to add such a button on my own 1200, I'll post here when it's done."

where can i check which pins to use?
only two wires and a switch, or 3 wires?

[frost242]

The HRTmon.guide file explains how to wire an IPL7 button. You need one button, 3 diodes (1N4148 or their equivalent) and some wire.

Taken from the guide :
Here is the @{b}schematics@{ub} of this button:

IPL0 -------- >| ------\
|
IPL1 -------- >| --------------- button ------- GND
|
IPL2 -------- >| ------/

>| = diode.



IPL0 IPL1 IPL2 signals can be found on pin 83-82-81 of the expansion
port of the A1200.

Then, the main issue is to find a ground.

[musashi5150]

I built the above circuit on my A2000 from the HRTMon docs - works great. As said above the only difference for an A1200 version would be tracing back the lines from the expansion connector and a small solder point.

[spotUP]

I got tipped on a link on how to do it:
http://user.it.uu.se/~jesperw/se/amiga/lev7.shtml
It's swedish though.
And i've successfully installed a L7 button now!
You don't need to use the tiny holes, solder at the very edge of the connector. The Blizzard fits anyway.
There's plenty of grounds on the CPU connector too. NP.
Mine works as expected!
Only problem now, is that Toni Wilens romable HRTMon won't always start.
It starts when an WHDLoad app is running, but not else.
When I tried it in UAE with my custom ROM i could activate it all the time, but not on my real A1200 with HRTmon blizkicked.

[Toni Wilen]

My A1200 NMI "switch" finally done. R953A-C resistors were the easiest location after all (underside)

HRTMon in EPROM also works, even in "insert disk" screen, with or without 68060.

Images attached.

[h0ffman]

Reviving this thread as I'm thinking of installing the L7 button myself. Great picks Toni, will more than likely take those solder points you suggested. Was wondering where you hooked the ground up too?

[Geijer]

Just installed NMI on two A1200 with the help of Tonis pictures, thanks.
Any good points to connect the NMI on the A4000?
Zorro III doesn't seem to include them.

[Leffmann]

Are the diodes necessary, or just a precaution? Did anyone find any better points for getting IPL0-2?

[Jope]

They are necessary, otherwise the different signals would affect each other.

[Leffmann]

Yes you're right of course, since all lines are connected before the single-pole switch. I would need a triple-pole switch for it to work without diodes. Is it recommended to get a fancy switch or button free from contact bounce? The software side of things can handle the effect of this, but what about the CPU?

[Jope]

I wouldn't be too concerned about it.