Original CIA chip (391078-01) - not PLCC, for A1200

[Drag0nFly]

Hi,

(disregard the title for this as it is misleading, thanks @Sveta. It should more accurately say "not PLCC socket")

I am looking for an original (to be soldered) CIA chip (391078-01), with contact pins, for an Amiga 1200 motherboard. This is in order to use an adapter over the chip to provide wireless USB keyboard functionality (had mine placed in a socket as part of an upgrade, due to various miscommunication with the seller of the adapter which indicated that it was for the *keyboard MPU* on U13 and not the CIA-A chip on U7). As such I am in a bit of a dilemma and I see replacing the chip in the PLCC socket (and removing the socket) as the only option to fix this.

Appreciate any thoughts and offers.

 

[Sveta]

Hi,

PM with offer. Btw. A1200 has only PLCC version 8520 ICs. (your title is wrong "not plcc, for A1200")

Regards, Sveta

 

[Drag0nFly]

Just to further clarify, as all the chips I am seeing for sale are for use with mounting in a socket; I need the type with pins for soldering onto a PCB. I.e, *not* this:



In other words, an identical chip to what is on every unmodified A1200 mainboard (first picture in this thread), as mounting an adapter on these which sit in a socket is nigh impossible as the contact pins are not exposed.

 

[Sveta]

Hi,

Yes. I have PLCC 8520 IC On your photos is 8520 PLCC in extra PLCC socket. This is not original.

All A1200 MB has original/factory direct soledered without this socket.

PM. Photos via PM sent.

Regards, Sveta

 

[Drag0nFly]

@Sveta, thanks for the offer and your help, but I feel we're talking past one another here. The only reason I wanted to replace the chip was to use it with an adapter, which is impossible when it sits in a socket (hence the reference to the original CIA chip and the first picture in the thread). So I would need to de-solder the socket and solder in a CIA with contact pins (sourced from an unmodified A1200 mainboard) and put that in place instead.

See below picture which shows USB-keyboard adapter mounted on top, on an unmodified non-socketed motherboard (piggyback, similar to Indievision for the Lisa chip). Also sent you a PM with this info.

 

[Sveta]

Hi,

OMG

You have on your A1200 PLCC 8520 in PLCC socket and this is due probably swap/fix with new 8520 BUT here is not possible plug any adapters on 8520 chip due socket. You must before unsoldered socket and soldered 8520 direct to board.

8520 DIP is only for A500, CDTV or A3000, A2000

Regards, Sveta

 

[Drag0nFly]

Exactly. (and again, this was primarily due to the seller of the keyboard adapter indicating it would mount over U13 (mpu), not U7, otherwise I would have kept the CIA-A as-is)

 

[Drag0nFly]

So if anyone has chips they've desoldered as part of an upgrade to socketed chips, do let me know. It would help tremendously, as I do need to use a wireless keyboard with this A1200.
(I assume there are no NOS stock for these with contact pins underneath and will have to be fresh working pulls...)

 

[drbrain]

You have a fully working A1200 now with an CIA 8520 in a socket, right?

All you have to do is remove the chip from its socket, de-solder the socket and then re-solder the CIA you just removed directly to the motherboard.

The CIA in a socket is EXACTLY the same as the ones you solder directly to the mainboard.

There are only two variants of the CIA, Either the big DIP one (A500/2000/3000) or The smal square (A600/1200/4000)

 

[Drag0nFly]

Aha, really(!)icard From looking at the picture of the A1200 mainboard it seemed like it had pins underneath (solder-through). Obviously this would make the whole effort simpler for sure; and I also have spare CIAs and other chips in this format – thanks @drbrain. (Now I feel stupid!)

- - - Updated - - -

And this is natually a last-resort, as the benefit of having it mounted in a socket is very useful. This is good news as I also was thinking to replace the Lisa chip on a different, 1d, motherboard (which glitches *hard*/loses video output at the end of Virtual Dreams & Fairlight's "Love" demo, during the end screen render), which means I have spare NOS chips for that as well (assuming it actually is a fault w/ Lisa).
Why did I think there were two different types? (wtf)

Since there was a facepalm-deficiency above, I am including a couple more here to remedy the situation. :double:doublepicard:double:double