As I see it, the 8049 is available as an 8749 and can still be sourced, so in theory it is possible to still reproduce the original IPC, but that said, a Hermes or SuperHemes would be more desirable - but both these are rare to find now - is the source for these available? A total modern replacement is a possibility, but would be hamstrung by the oddball messaging between the QL and the IPC
These still turn up on eBay from time to time, but these are no longer being made or available once that source dries up - from what I see this is not a chip that fails that often, and it would be retained by anyone who'se switched to Aurora, so quite where the surplus are coming from - I don't know. If it was to be replaced - maybe in conjuction with the IPC - what would be the wish list for such a device?
This is harder of the 2 logic chips to find, and the one most likely to blow - seems the unprotected video outputs are a possible source of failures - and work to address that in the proposed issue 8, as a replacement part in the BBQL it is a timing criticial component too, so any replacement has a lot of specifications to adhere to. On top of that, the flat RGB output from the chip at a sligltly non standard timing of standard baseband video signal limits it's options on what monitors can be connected. I have had success with some CGA/Analog to VGA adaptors, and a SCART to HDMI has worked all be it with a bit of noise and shadowing, but this would be a good chip to find a replacement for. Adding extra video modes and colours not so straightforward - particularly if it will end up in the same 40 pin socket.
So various discussion topics -
- pin for pin compatibility?
Maintain all existing functions?
Improve if possible existing functions?
Piggy back boards offering new functionallity and maintaining/replacing existing?