Sinclair ZX80 / ZX81 / Z88 Forums

Greetings! Is there such thing as "Sinclair Burnout"?

Good point. I am waiting on Rev 0 of the board for prototyping, perfboard style, of various potential configurations of the kit. I can see them in my mind in the cargo-hold of a slow moving freighter across the Pacific getting lost in the Japanese Dragon's Triangle comparable to America's Bermuda Tr...

Get out your tomatoes... I propose
My design philosophy in one direction is what should the Sinclair computers look like if you had a do-over.

https://www.sinclairzxworld.com/viewtop ... =10#p29799

The keyboard map to adapt to ZX81...

This is what I worked out and 75% of 40 keys are already wired! 10 need rewiring and the rest need special circuitry and latches to utilize them for the ZX. TIKEY IMG_20180215_173237.jpg D1-8 IS DIODE 1-8 / ASSIGNED TO A8-15 / I HAVE NOT CHECKED THE ORDER ..GOING OFF SCHEMATIC DON'T CONFUSE WITH K0-...

I noticed that some chip pinouts do not show active high or low. I added this in case anybody wants since others pointed out.

I'll take ten! Wait wait wait maybe I shouldn't get so excited. Maybe one. Maybe I should finish Issue 1 first.

Don't think D5-D7 should be grounded without a resistor...

Maybe need a momentary pushbutton for /CE on EPROM? Set DIPSWITCH. Press button.

Is /RD (The first purple wire on the left) shorting to /WR (The first unattached pin on the left )?

May or may not be related but when I first started using SD cards with ZXpand I had problems so I moved files on windows and the reformatted to 4MGB FAT16. More than enough space right? And then copied them back onto SD.

Then the problems dissappeared. Maybe a file disk fragmentation problem.