Re: My Klyball 600D build
Posted: Fri Feb 02, 2024 11:54 am
So, the clock circuit is definitely saying no.
I have 4 Mhz at pin 5 of U79 and pin 4 is connected to ground, but there is no output at all on pin 6, so by connection, none at pin 9, so I only ever get 4Mhz out at pin 8, the same at pin 1 of U29, and of course then I just get 500KHz out at pin 11 of U29.
I've tried swapping U58 (7400, 74S00 & 74LS00), U79 (74LS86) and U29 (74LS93). All the removed chips test just fine in my TL866 Pro.
I've also swapped out C57 and C65, and those parts also tested fine. Last night I also removed the sockets for U58 and U79 to check for shorts underneath, despite everything buzzing out OK. No difference with new sockets in.
No matter what I do, it flatly refuses to deliver 8Mhz from the LS86.
I have just received an 8MHz xtal, so I am going to try and switch the clock circuit to that of the 600's UK sibling, the UK-101, which dispenses with the clock doubling trickery of U79 and uses an 8MHz clock going straight to U29.
I'll report back when I've had the chance to test this out.
I have 4 Mhz at pin 5 of U79 and pin 4 is connected to ground, but there is no output at all on pin 6, so by connection, none at pin 9, so I only ever get 4Mhz out at pin 8, the same at pin 1 of U29, and of course then I just get 500KHz out at pin 11 of U29.
I've tried swapping U58 (7400, 74S00 & 74LS00), U79 (74LS86) and U29 (74LS93). All the removed chips test just fine in my TL866 Pro.
I've also swapped out C57 and C65, and those parts also tested fine. Last night I also removed the sockets for U58 and U79 to check for shorts underneath, despite everything buzzing out OK. No difference with new sockets in.
No matter what I do, it flatly refuses to deliver 8Mhz from the LS86.
I have just received an 8MHz xtal, so I am going to try and switch the clock circuit to that of the 600's UK sibling, the UK-101, which dispenses with the clock doubling trickery of U79 and uses an 8MHz clock going straight to U29.
I'll report back when I've had the chance to test this out.