Search found 25 matches

by tocksin
14 Jul 2018, 20:48
Forum: Hardware and software hacking
Topic: High resolution mode?
Replies: 38
Views: 38274

Re: High resolution mode?

I'm thinking to get both the high-res and low-res modes, we could add a 2:1 analog multiplexer: 74HCT4053. We'd need two different resistor arrays, but this would be a simple solution. Then we could pull a line from the blinkenlights to the select line. OR as a more advanced option - we could captur...
by tocksin
13 Jul 2018, 13:58
Forum: Hardware and software hacking
Topic: Extending the Gigatron instruction set
Replies: 22
Views: 16810

Re: Extending the Gigatron instruction set

What about something a little less intrusive? I'd hate to become incompatible with the current instruction set with all of the work people are doing developing the software. What if we just replace the instructions which are currently unusable? Specifically, the store instructions which write to RAM...
by tocksin
10 Jul 2018, 23:26
Forum: Hardware and software hacking
Topic: High resolution mode?
Replies: 38
Views: 38274

Re: High resolution mode?

Yes with 6 color outputs per 1 pixel we could reduce it to 3 color outputs per 2 pixels. It's still a color reduction when going to 320 pixels, but probably worth it to get to 40 characters per row for a text mode. It may still work with an asymmetric clock. It depends on when the VGA monitor sample...
by tocksin
10 Jul 2018, 17:08
Forum: Hardware and software hacking
Topic: High resolution mode?
Replies: 38
Views: 38274

High resolution mode?

I was thinking of ways to increase the resolution video output. Right now it takes one instruction per pixel, so you can't really optimize that. But I was thinking what if did two pixels per instruction? Maybe if we do a DDR (double-data-rate) trick by putting a 2:1 mux on the OUTPUT with the clock ...
by tocksin
27 Jun 2018, 13:01
Forum: Hardware and software hacking
Topic: Keyboard hookup with minimal means (dream)
Replies: 19
Views: 15010

Re: Keyboard hookup with minimal means (dream)

I envision an embedded keyboard in a "Gigatron 2" platform. It would have one PCB with both the DIP chips and the keyboard switches. In that design it would be very easy for the software to sample the matrix keyboard without the addition of more chips. For example, the output bus is not us...