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Old 3rd Nov 2020, 7:28 pm   #60
SiriusHardware
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Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,484
Default Re: I found it !. A very sorry looking MK14

Good idea to acquire one of the issue VI PCBs to use as a test bed for the ICs from your original system. Hopefully you can be a third eye on the VDU project at some point as well. There is an extra IC in the issue VI, a 74LS20 (U20) so make sure you have one of those available as well.

The IC north-west of the display with the IC 'U' number and the device number tangled up on the screen printing is either an 80L95 (as per original) or can be substituted with a 74LS365. I think Tim has tried one or two other variants in that position as well.

The two 7408s behind the display have to be 'original' 7408s and not 74(something)08. It's OK to use a 74LS08 in the U16 position, as indicated by the screen printing.
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