Sinclair ZX80 / ZX81 / Z88 Forums

Hey Vopni. Thanks for the complements. Yes, a lot of time and effort have gone into this project and none of it could have been possible without the help and information from a lot of great folks on the forum. Standing on the shoulders of giants, as it were. I don't have them for sale yet due to a c...

Yes, the 74LS138 was fitted. I'l try your suggestion using only one RAM chip at a time in those locations.

Then I'll probably just sob quietly to myself over in the corner.

Mike

Hey Mark. Yeah I probably mis-named the 74LS138 1 of 8 Decoder / Demultiplexer IC as a "timer" chip out of my abundant ignorance. Thanks for the info on addressing schemes on the machines. That's good stuff I am trying to digest. The TS edge connector has little wear and is clean. Plugging my ZXpand...

Mark, I just received a fresh batch of 2114N-2 chips and tried them on the board both fully populated and in pairs as shown in the drawing you posted. Still no joy. Also tried having only the timer chips installed. Got "K" prompt with one and nothing on the other. So I went back over all the connect...

For the truly adventurous, here are the .STL and .gcode files for the belt with no posts. It is up to the user to implement a method to attach the styli. I will be happy to assist in any way. Like the previously posted file for the belt with the integrated stylus mounting posts, these files are also...

Finally re-posting the .STL file in ZIP form for the ZX printer belt with the stylus mounting posts. It is passworded, so those wanting to use will need to PM me for the password. I am doing this to restrict access to those who have been of such great help in the development of this project, so plea...

Mark, That is an excellent suggestion I hadn't considered as a means of controlling access. I want to share among you guys who have been so incredibly helpful while being selective at the same time. This solves that problem nicely. MaFli, Apparently great minds must think alike! You are doing someth...

That's good to hear, guys. What I have decided to do should make everybody happy. The belt with the styli will be sold on SMR as previously mentioned. I will repost on this forum the files for the belt with the do-it-yourself mounting posts as well as helpful tips for successful printing. These I ho...

Thanks for the info, Mark. I had seen the extract of the instructions before, but somehow failed to save that particular page. Just received a fresh batch of 200ns 2114's yesterday, so I'm fixin' to go see what I can do using the info you guys have posted. BTW, I am attaching photos of both sides of...

Hey Mark, no worries about your posts. As soon as Will gives me a test report on the belt with styli I sent, then the rest will follow from there. I'm 99.99% certain it will be fine, just need that added assurance since the Fleabay printer I purchased turned out to be a dud. At least it had a 30-day...