View Single Post
Old 15th Oct 2018, 8:45 pm   #98
SiriusHardware
Dekatron
 
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,485
Default Re: MK14 schematic revisions

Well done Slothie - I'm especially glad your PROMs turned out OK since they must literally been to more different countries now than I have in my lifetime.

At first glance it seems you might get away with just cutting and reversing the order of the column / cathode driver outputs from the 7445 to the display and keypad, but I haven't really thought it through so don't take my word for it. You could try it by fitting a socket with the appropriate number of pins onto a bit of veroboard and wiring that into a header plug or another socket with the output pins rearranged in reverse order, then plug that into the original socket for the 7445.

Considering this was just a 'thing you decided to do' completely from scratch, I have been impressed by your dogged determination to succeed, and it finally seems to be paying off.

If the mystery of the 74157s so intrigues you, once you have it working you can knock yourself out trying out all sorts of different brands of 74157 and post the results in a nice table here.

Last edited by SiriusHardware; 15th Oct 2018 at 8:51 pm.
SiriusHardware is offline