ZX Spectrum 128 +2 (Grey) Schematics.

[MonkZy]

I have a grey +2 with a the board revision Z70700 ISS 1. This is the UK made board which was slightly redesigned to use axial capacitors. Is the schematic for this board identical to the Z70500 ISS 3 board?

Also, I am trying to confirm the pinout of the cassette drive connector. I have worked out pins 1 and 5 are GND, and pin 3 is +5V but I cannot determine which pins are EAR and MIC. Using my dodgy ASCII diagram, when viewed with the board in front of you, is pin A the EAR or the MIC connection?

Code: Select all

	GND		o
			o	A
	+5V		o
			o	B
	GND		o

I have searched the web and attempted to trace the tracks but cannot determine for sure which pin is pin 1 on this socket.

[Sparky]

This might help


Full link for larger view
https://spectrumforeveryone.com/wp-cont ... matics.jpg

[Ast A. Moore]

Just buzz out either pin (2 or 4) of the connector to pin 35 on the ULA and you’ll get your MIC, which is pin 2.

[MonkZy]

I followed

Just buzz out either pin (2 or 4) of the connector to pin 35 on the ULA and you’ll get your MIC, which is pin 2.

I did this. The pin out is as follows :

Code: Select all

GND		o
		o	2. MIC
+5V		o
		o	4. EAR
GND		o

Thanks