Gigatron Hackers

Ah yes, Xpp is also X++. The pp part is "plus plus," so post-increment X.

Yes, that was what I assumed as I was first reading. The controllers operate at different voltage levels and have some quality control issues. As for where the inputs were coming from, I would guess it could be an improperly soldered connection in the controller. It is a serial device, so it would n...

I've noticed that.

Thank you Monosonite! I agree, the Gigatron fits the design philosophy well. I'm seriously considering spinning something similar. I think I'd want to play with some working pulls of the limited 16-bit ALUs that were around. They could replace at least 10 chips (and possibly more such as the accumul...

For a Gigatron-similar machine, it might take more than 20 chips to double the ALU width at a reasonable speed. That would likely double the worst-case latency since carry ripples don't scale well. You'd have 2 additional ripples. There used to be a carry generator chip to speed up adders and ALUs, ...

I will ask again: Does any software rely on the row and column data? I don't mean the indirection table, but the current line that is being processed on the screen. I mean, how does it know which line to start on and which indirection entry to look up? How does the clock program know how many second...

I'm trying to figure out the best way to do a Gigatron-similar machine with a 16-bit native machine under the hood. The vCPU code can still be 16-bit. The memory map could be different. It could use a 16-bit memory map. I know of no old CPU that did that. So how far should I take it being 16-bit? Fo...

Here is a thread for art and media involving the Gigatron.

For instance, I could write parodies about the Gigatron TTL computer.

To the left, to the left,
The ALU is the chips to the left.
The top right the program counter
Near the center the SRAM.

(Apologies to Beyonce)

If you want to eliminate the diodes, options include high-speed transistors if you can find them, or PAL/GAL chips. But if you want just a little faster, use Toshiba SMD diodes. You can get them individually and in multi-diode packages. One alternative could be to use an ALU chip. I don't mean the '...

I looked at the schematics and have some questions. * Could the upper multiplexers driving the memory be replaced by a buffer? I notice that the multiplexers are not wired as I'd expect. The 2nd set of inputs are all tied high. I'd think they'd be tied low to mute the Y register and allow Page 0 ins...