Calling All 1200 Experts!

[gklinger]

I need some (more) help from one of our resident hardware experts...


I'm trying to figure out exactly what the numbered spots/solder points are for. With #8 I know that the bottom set of pins are for the case LEDs so I'm wondering about the set of pins above it (I worried that making the box smaller would lead to confusion). I suspect that this information might be available on a schematic but I don't have nearly enough knowledge to figure one of those out.

Any answers would be more appreciated. Thanks in advance.

[Paul_s]

I'm pretty certain number 3 was for a maths co-processor...

[meega]

I think #4 is "remainder" clock-port connector points.

#8 has my floppy drive plugged in above the case leds.

[Paul_s]

no 5. is for a Real time clock

no. 6 EDGE-90 Memory Bus Expansion(very OLD! model) and Real-Time Clock/Calendar

no 3. is deffo the fpu - 68881 68-pin PLCC

I'm getting info from here although it's not fully complete... http://www.amigahistory.co.uk/a1200info1.txt

[gklinger]

Originally Posted by Paul_s

I'm pretty certain number 3 was for a maths co-processor...

That seems logical given the size and shape.

Originally Posted by meega

I think #4 is "remainder" clock-port connector points.

That makes sense as it is right beside the other one.

#8 has my floppy drive plugged in above the case leds.

D'oh! I knew that. I probably shouldn't have started drinking with lunch.

[Zetr0]

1. Test Point [TP 1 and 2]
2. Test Point [TP 3]
3. FPU 68882
4. Clock Port Header
5. Clock chip
6. DRAM Port
7. defunct component
8. LED/Power Header
9. Activity Coupling



4.
This is infact Clock Port 2

6.
This was intended as the a chip ram expansion as the A1200 was gonna have 1MB)

9.
Here is the Activity Coupling for the LED's, you can add a small trimpot to the arrary and give yourself PCMCIA Activity LED

[gklinger]

Originally Posted by Zetr0

4. Clock Port Header
5. Clock chip

Is it possible to add another clock port or a clock chip itself? Just curious.

[rkauer]

Maybe. Nobody even try. Neither the soldered FPU, nor the PCMCIA activity LED (wait! this was made!). The problem is the shape of the clockport boards, all intended to fit just on the right cp.

[Doobrey]

Originally Posted by Zetr0

4.
This is infact Clock Port 2

Nope, no 'clock port' signals there. The unused pins on P9B are just D0-15 of the chip ram data bus, +5v and ground.


Edit: BTW, both P9B+P9A were the connections for the 1MB chip ram expansion. When they decided to ship with 2MB, they removed all the pins for the expansion except for those needed for an RTC.. so the right side of P9B got known as the 'clock port'