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Re: QL 34th Anniversary new hardware.
Posted: Thu May 24, 2018 9:24 pm
by Dave
And, after a slight detour for emergency home renovations that took too long, the 4M respin is now at version four and 99% complete!
The video adapter is also 95% complete on version two. I am just weighing up reasonableness of adding support for a SCART connector instead of RGB/S-Video/Composite sockets. As the sockets are on an external plug-in PCB on a short cable, either could work. Catch is SCART uses some odd voltages to signal formats and ratios, and I'd have to redesign the main board to accommodate that.
Re: QL 34th Anniversary new hardware.
Posted: Fri Jun 01, 2018 12:48 am
by Dave
The 4M card just clicked over from 99% to 100%!
Goals!
Still working on the custom output board for the S-Video card. Maybe later today.
Re: QL 34th Anniversary new hardware.
Posted: Fri Jun 01, 2018 1:40 pm
by Pr0f
Congratulations Dave
Re: QL 34th Anniversary new hardware.
Posted: Fri Jun 01, 2018 4:37 pm
by Whopper
Let me add my congratulations Dave.
Re: QL 34th Anniversary new hardware.
Posted: Mon Jun 04, 2018 5:53 pm
by Dave
New batch of prototype PCBs ordered.
Re: QL 34th Anniversary new hardware.
Posted: Fri Jun 22, 2018 6:56 pm
by Dave
Following my tracking and the PCBs will be here in just a couple more days. WOO!
Meanwhile, over the last few days I have been trying to reverse engineer the 8302/8049 combo to produce a replacement. I have a primitive AVR keyboard matrix system running, but don't really know how the keyboard buffer works - especially in regard to CTRL, ALT, SHIFT. However, Nasta's doing a lot of handholding and extensive explanations so it will come together. One of the main difficulties I am having is that the 8049 pins are naturally high and pull low, whereas the pins on the ATSAM3X8E are fully tri-state, which makes it easier for me. I have to keep reminding myself that I just have to implement the functionality, not use their methods.
Once you hand off serial to a 68681 or similar, sound to a dedicated sound chip, drop MDV and QLnet, the 8301/8049 all fit in a single AT328P and 74HCT138. I am leaning towards the SAM3X8E though, because it has multiple serial ports, I2C, SPI, and can do almost everything a growing system needs - and with 32-bits width too!