Gigatron Hackers

However, my second system is equipped with a Gigatron RAM and IO expansion. When trying to boot from SD card using a recent system.gt1 the browser did not start. I believe this ROM only supports Pluggy Reloaded and not the RAM and IO expansion. You would need to use lb3633's DEVROM for that. I‘m cu...

renzo wrote: ↑10 Dec 2022, 01:01 Since pin2 is fixed to low level state (let's say low half 64k), I expected to see 64KB on the boot screen, insted I get "Gigatron 128K".

This is a known issue with ROMv5a. viewtopic.php?p=3182

https://support.github.com/ticket/personal/0/1516900 Hi, anyone ever had to deal with GitHub support that might have a suggestion on what to try next? Earlier in the year I chatted with at67 and walter about getting some scripts set up on the Gigatron Discord to automatically post when the gigatron-...

https://forum.gigatron.io/download/file.php?id=1451 shows the PC incrementing from 0x1FF to 0x200, so no load is occurring. You have confirmed the PC is reset and at least in this waveform incrementing correctly. What I perhaps erroneously assumed was that your PC[15:8] was being loaded with the wro...

Where does it start to deviate? Where the PC starts deviating from the ROM listing and whether it's consistently the same deviation will tell you what is wrong with your hardware. Are you saying that you see PH_B go low and then PC9 goes high the next clock cycle? When PC[11:0]=0x200, PC9 is high an...

If you're trying to use SD browser for SPI expander then I'm guessing DEVROM, otherwise v5a is the latest official ROM available publicly. I skimmed through the P2 thread. Quite impressive how quickly Roger turned it around.

Good to hear you got it working so quickly. The Menlo FPGA code had a similar issue for me but I fixed it by sampling on a falling edge and delaying PULSE by 80ns and it's been consistently working with 4021/165 based controllers. He/She never reported it as an issue, so I'm guessing that whatever c...

Outstanding! I didn't get what you meant by "it is well suited for extension to lb3361 extension-retro" until I saw the photo in the Pluggy Reloaded thread showing how the headers lined up. Looking forward to your updates!

DOH, my bad. I was expecting to see LATCH and forgot that it feeds the DB9 pin directly.

Not sure if Rev 1.3 is a downrev schematic, but HSYNC_B shouldn't be wired up to the 595 twice on pins 11 and 12. I assume you already addressed that.