The Sinclair QL Forum

Hi All,

I'm a bit confused. Not an extraordinary state of mind for me I'll admit, but this confusion relates to a QL motherboard.

The board I'm working on currently shows that it is an Issue 5. Says so on the back. However,
1)The board doesn't have IC17.
2)The ROM is the 48K JM version.
3) JU2, JU3 & JU4 are connected.
4)The QL service manual PDF that I have has a hand written note that states that "48K, As 8 above with piggyback EPROM on IC34. All pins soldered except 22 which is connected to 'X.'
5)Configuration 8 states that "IC17 is an LS00, Put in JU1, JU6 only."

So is my board an Issue 5.0.397b, or some such similar sub type? Any help would be most appreciated.

Whopper

It's a later Issue 5, build standard D11 thru D14.

Note a lot of the earlier boards have been factory upgraded when sent in for repairs. So all sorts of mods might have been done depending on when exactly the repair was needed.

Tobias

Thank you Gentlemen for your replies.

For a follow-on question, just which circuit diagram do I use now, iss5 or iss6?

Still a confused Whopper.

You'd use the Issue 5 details as that's the PCB it's based around.