Despite feeling crappy after my booster Jab, I wanted to do something to keep me occupied and not thinking about it too much.
So I went back to the 1050, intent on shortening the bodge wire as it seemed to have a bit of noise on it causing the drive to sometimes fail to initialise.
Since I'd replaced U16, a 74LS04 and U12, a 74LS00, I figured it couldn't hurt to drop them back in for a quick test.
I changed out U12 first, the 74LS00, and the one I'd had to bodge wire to the FDC chip select from. No different with the old chip in. Sometimes worked, sometimes not.
So I dropped in the original 74LS04 into the U16 socket, and lo and behold it worked. I tried a second new 74LS04 and the same result, sometimes it worked, sometimes it didn't and scoping pin 9, which feeds U12, with the brand new chips, the signal is super weak and only occasionally works.
Incidentally, the new SN74LS00 worked just fine with the old 74LS04.
The only difference I can see between the new and old chips is that the old is a 74LS04, the new ones are SN74LS04. I can't find if SN makes a difference (I know HC does), bot for now I've reverted to the original as it works every power on.
Time to test if it works with a real machine.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...