[cctalk] Re: Hot Video Shift Register on VT100

If similar ones don't get hot, I'd suggest pulling the part from the board. Use a 250 ohm resistor to ground on the outputs. If anything goes higher than 0.4V, there is a problem with the load. You want the part removed so you are not looking at the part pulling up. With the part still removed, it should also go over 1 Volts with a high impedance voltmeter or scope. Dwight ________________________________ From: Rob Jarratt via cctalk <cctalk(a)classiccmp.org> Sent: Wednesday, December 24, 2025 3:47 PM To: 'General Discussion: On-Topic and Off-Topic Posts' <cctalk(a)classiccmp.org> Cc: Rob Jarratt <robert.jarratt(a)ntlworld.com> Subject: [cctalk] Re: Hot Video Shift Register on VT100 I just double checked and on the other unit it is a 74S299N, identical to the one that gets hot in the VT100. I suspect it is OK for it to get hot and maybe I should just stop worrying about it. But it is puzzling as to why this one gets hotter. I will get my VT101 back soon and I can see how that compares. Thanks Rob