Issue 8 discussions...
Posted: Wed Mar 20, 2019 11:49 pm
Sooo, to kick things off, would people be terribly offended if all the 7400 series logic was SMD instead of DIP?
The Home of Everything QL!
Peter wrote: But I'm interested in high functional and mechanical equivalence to the QL.
NormanDunbar wrote:I suppose that question depends on who is having to do the soldering ("soddering" for the USA
I've done some hand soldering of SMD stuff, and it's a tad finiky, but no tombstones. (Yet!)
Peter wrote:Especially if only larger, easy to solder SMD footprints like SO are meant, that's absolutely fine for me. But I'm interested in high functional and mechanical equivalence to the QL.
For my taste, it should be able to run 128K RAM if configured, support microdrives, and unchanged operating systems. I also like the idea of re-seating most socketed QL chips to this board.
For me, the Issue 8 board should cover those traditional QL features, looks and add-ons the Q68 can not offer.
If I designed the board myself, I'd be in temptations to improve and change a lot of things. But I think most of those temptations should be resisted. Make it a true QL, very last Issue!
Dave wrote:Currently, it looks like the machine will have Minerva at launch and SMSQ/E shortly thereafter.
Dave wrote:I've been quite intrigued by an idea you explained in a post a couple of years ago, which would greatly simplify booting and occupying shadow RAM in the ROM areas.
Dave wrote:It does support microdrives and QLNET under Minerva. If the system is supplied with a slightly faster clock, we will modify Minerva so timings are correct.
Dave wrote:The main area of discussion right now is the video subsystem. It's a possibility we might move the whole thing including 8301, internal video RAM, 245 and 257s to a daughter card, so the entire video system could be upgraded later.
Dave wrote:I do have a number of 32K dual port SRAMs, which would completely free the CPU from video timing constraints. This could more than double the speed of the QL and remove a lot of timing restrictions.
Peter wrote:Dave wrote:Currently, it looks like the machine will have Minerva at launch and SMSQ/E shortly thereafter.
The explicit mention of these two bewilders me a little. I hope the board remains so close to the QL, that unchanged QDOS works also. (And I think you mentioned that earlier.)
Nasta wrote:The main difference in ROM sockets is that they will be quality turned pin ones
Nasta wrote:The timing is changed in the sense that everything can work ~zero wait but the default clock is still 7.5MHz exactly the same so MDV, NET all work excatly as before.
Nasta wrote:The one thing we are debating at the moment is screen 1 support, so opinions on this are welcome.