The Sinclair QL Forum

Arleybls wrote: Fri May 16, 2025 7:42 pm I am afraid that will not do any good given the socket type on the QL is not hollow (at least on mine ) SO you would have to change the socket first to create space

Well the PCB won’t be sitting flush on top of the socket because of the plastic spacers on the legs and the centre of the QL socket is slightly lower than the edges.

I’ve compared dimensions with one of Chr$ ROM boards (which fit fine) and my measurements suggest it should fit

Only one way to be sure though!

The thing that really confuses me though is that the pictures of original boards I’ve seen are socketed!

I just tried bending the pins on a similar (spare) IC and it worked without any breaks

I then did a dry fit (along with EEPROM & QL socket legs) which shows just a bit of trimming on 74LS133 legs (under EEPROM) & one set of QL legs will allow all the parts to fit snuggly to the board

It comes out at the same height as one of Chr$ ROM boards and 74LS133 won’t need any space in QL ROM Socket

The big question is whether I can do it for real!

Decided to give it a go and see how I got on (haven't checked the soldering yet!)

All sockets removed and the 74LS133 is now upside down underneath (I didn't have any problems bending all the pins upwards). I can't see any reason why this wouldn't fit inside a QL height wise now, though yet to try it

Only tested it as a ROM and RTC, but all seems good


The top of the 74LS133 sits lower than the plastic collars of the QL legs so can't foul the QL socket

Edit: when I say “top” it’s actually the bottom of course