Search found 48 matches
- 09 Nov 2019, 15:21
- Forum: Hardware and software hacking
- Topic: Modified Gigatron Design Ideas
- Replies: 57
- Views: 60888
Re: Modified Gigatron Design Ideas
Thank you for your reply and info. The FIFO sounds interesting, though I am unfamiliar with most of the signals other than Dx and Qx. It is interesting that the one you propose has 9 bits. I think they added the last bit for a traffic sync signal, but that could easily be used as a color bit. On the...
- 02 Nov 2019, 03:29
- Forum: Escape Meta Alt Control Shift
- Topic: On the shoulders of Giants
- Replies: 6
- Views: 7683
Re: On the shoulders of Giants
Since I see you now have ports planned, I'd like to make a suggestion. I think you should use the 8 bits at the end of the instruction to specify a port address. That way, you could support up to 256 ports. And whoever makes peripherals could use simple address decoder logic to see if it is the devi...
- 02 Nov 2019, 03:16
- Forum: Hardware and software hacking
- Topic: Modified Gigatron Design Ideas
- Replies: 57
- Views: 60888
Re: Modified Gigatron Design Ideas
What would be a decent FIFO to use? I never really thought of FIFOs and shift registers. So any information on those would be a good start. Now I am not sure how such a card can tell the Gigatron that it needs data in its FIFO registers or how software could get it. There is currently no way to sign...
- 31 Oct 2019, 07:33
- Forum: Hardware and software hacking
- Topic: Modified Gigatron Design Ideas
- Replies: 57
- Views: 60888
Re: Modified Gigatron Design Ideas
A compromise comes to mind. The existing clock (or a clock divider if going for 12.5 Mhz) could be used to drive a pixel counter. The idea of intercepting a NOP instruction to create a video reset could be used on power-up to reset the pixel counter and any other time the pixels being sent might not...
- 21 Oct 2019, 00:13
- Forum: Hardware and software hacking
- Topic: Pluggy Reloaded
- Replies: 149
- Views: 117203
Re: Pluggy Reloaded
From what I see, VCC comes from the Gigatron. The USB's VCC comes from the controller chip, and that chip gets it from the Gigatron. I am wondering if the VCC to the chip and the VCC to the USB port are not wired the opposite way on the controller. It seems VCC on the chip should feed the chip and t...
- 21 Oct 2019, 00:01
- Forum: Escape Meta Alt Control Shift
- Topic: On the shoulders of Giants
- Replies: 6
- Views: 7683
Re: On the shoulders of Giants
I've been thinking more about a Suite-16 being used as a Gigatron. Obviously, you'd need at least 1 IN port and 2 OUT ports, and ROM. If you had a 16-bit X-Out, I could think of various ways to use those bits. For instance, if you wanted blinkenlights, that leaves 12 bits, and you could have 2 6-bit...
- 20 Oct 2019, 20:50
- Forum: Escape Meta Alt Control Shift
- Topic: On the shoulders of Giants
- Replies: 6
- Views: 7683
Re: On the shoulders of Giants
I notice that you sort of planned to address 24-bits of memory by combining the payload with a register, I also read that your jumps and calls are 16-bits. I got to thinking that you could use the payload byte along with the next 2 bytes and do 24-bit jumps and calls. But then I read that you might ...
- 19 Oct 2019, 03:06
- Forum: Hardware and software hacking
- Topic: dual ported SRAM for co-processing
- Replies: 5
- Views: 5438
Re: dual ported SRAM for co-processing
An idea I had was to put 32k dual-ported RAM on 2 Gigatrons and do crisscross addressing. Instead of using the high bit to address larger memory, it is used to switch a multiplexer and address the memory on the other machine. So the low 32k is the local Gigatron, and the high 32k is the other Gigatr...
- 18 Oct 2019, 20:49
- Forum: Hardware and software hacking
- Topic: Modified Gigatron Design Ideas
- Replies: 57
- Views: 60888
Re: Modified Gigatron Design Ideas
I already mentioned how I'd do a video card reset command. One of the NOPs can be piggybacked. They already do nothing. I never mentioned changing any, just adding functionality to one. So all it takes is adding minor decoder logic for the desired instruction. I mentioned how to NOR the pins expecte...
- 17 Oct 2019, 22:08
- Forum: Hardware and software hacking
- Topic: Modified Gigatron Design Ideas
- Replies: 57
- Views: 60888
Re: Modified Gigatron Design Ideas
I was talking about modifying a Gigatron. Since there are 12 NOPs, I could intercept one for use for the "video card" for it. Thus once I discover the opcode I want to intercept, I can use logic to see if the appropriate low bits are low and the high ones are high, make a single signal out...