Search found 4 matches
- Wed Sep 21, 2022 2:02 am
- Forum: Design Ideas 💡
- Topic: ADLIB/MPU-401 Expansion bay
- Replies: 7
- Views: 12658
Re: ADLIB/MPU-401 Expansion bay
TexElec now has an Adlib card for the PCjr.
- Sat Apr 04, 2020 9:34 pm
- Forum: Parallel Side Car
- Topic: Parallel Port Side Car items
- Replies: 17
- Views: 17921
Re: Parallel Port Side Car items
I may write formal instructions some day but am far from that point right now. I haven’t even touched my own parallel port yet, there are other things I need to investigate before I do, I have other projects competing for my time, etc. I just wanted to point out the unused NAND gates I saw before yo...
- Sat Apr 04, 2020 1:01 pm
- Forum: Parallel Side Car
- Topic: Parallel Port Side Car items
- Replies: 17
- Views: 17921
Re: Parallel Port Side Car items
Just out of curiuosity, did you try driving the LED from the first gate , LED and Resistor to ground. Should be enough drive to light the LED and get rid of the second gate ! Brightness ? Todd already tried sourcing the LED current, and it worked for him. I imagine it would work for others, too. I ...
- Sat Apr 04, 2020 10:57 am
- Forum: Parallel Side Car
- Topic: Parallel Port Side Car items
- Replies: 17
- Views: 17921
Re: Parallel Port Side Car items
FYI, all the gates you need are probably on the board already. I looked for spare gates on the schematic in the PCjr technical reference and only saw one NOR gate available. However, when looking at a board I have on hand as well as photos of other parallel port boards, I see a 74LS00 quad NAND chip...