Gigatron Hackers

We've seen this several times before, where it turned out the multimeter itself is somewhat flaky. See the Troubleshooting page. I would just continue, there clearly is an active signal present.

Hackaday's own write-up of the event is now here. The improvised Racer demo worked flawlessly on the projector. Maybe a next time we should present the slide deck from a Gigatron?

On 1: For moving AC to X, I would use this: ld ac,x It puts AC on the bus, lets the bus value pass through the ALU to the result bus unchanged, and lets X take the value from the result bus. On 2: The secondary destination, X or Y, in some store opcodes is a happy little accident. Store operations ...

Transfer a fixed number of bytes is suitable for writing to a SD card but not for reading. For init (must be do at low frequency) and read we need polling. I will explain how I did SD-card access in my library: I started to look at sdcard.c in more detail and compare it to the explanation in the PD...

You're missing nothing. The web page was simply wrong... Thanks for spotting! No idea how it got permuted, as this order has never changed.

manumenzella04 wrote: ↑29 Mar 2019, 03:32 I can see a signal (~60 Hz) on the PS/2 port, so that’s probably a good sign.

It is a good sign. In order to avoid having to deal with two clocks potentially arriving at the same time (Gigatron and keyboard), BabelFish disables the PS/2 clock each time it expects the vertical blank.

Indeed, means there are two sync signals coming from the Gigatron with roughly the expected duty cycles.

These signals are strictly inputs to the ATTiny. The code is in the repo: Utils/BabelFish/BabelFish.ino // +------+ // ~RESET --|1. 8|-- Vcc // PS/2 data PB3 --|2 7|-- PB2 Serial data out // PS/2 clock PB4 --|3 6|-- PB1 Serial latch in // GND --|4 5|-- PB0 Serial pulse in // +------+ // ATtiny85

This is something we haven't heard of before. Only a brief black out is expected when plugging into a life system. If another VGA screen shows the same issue, the ATTiny85 must be faulty in some way. Well, assuming it isn't accidentally reversed: the pin 1 indicator should be closest to the PS/2 jac...

I posted a photo impression on the Hackaday blog: https://hackaday.io/project/164176-giga ... nspiration