Development continues on ZAViouR. I've been doing a few bits and pieces with it but I get increasingly annoyed with myself for combining the AVRs serial lines with the Datalines. I made a small bar of LEDs to fully test the output, shown here in this video:
I shot this on my iPhone 6, but because of the way it records, it misses some of the LED flashes. All the LEDs flash in turn as they should do in reality.
I've added a few features to the new board.
- A 40-pin expansion port.
- SRAM size Option. Extra traces for Cypress CY7C199CN 32K SRAMs.
- A 'proper' power socket.
- A second indicator LED
- A Run/Inhibit switch to tell the AVR to run or stay 'Hands Off' at start up.
- A Micro-SD Card socket and header to provide storage via the AVR.
There may be other things to modify/add as yet so for now, I will continue with the ZAViouR v1.01. A couple of things I have done, apart from add the manual /BUSRQ switch is to add some pull-up resistors to unused lines on the Z80 (like /INT) and add a capacitor across the 'Reset Z80' switch for a kinder power-up. Currently it is a 10uf but I may increase that to make the start-up delay a little longer.