The Sinclair QL Forum

Yes, I have checked both Nasta's and Tetroid's schematics of Gold Card. (Something to do with locking data separator to crystal, or as an indicator of drive door open, according to datasheet, perhaps just used as way of reading QL tick) Can you tell me where I can get the Gold Card schematics? I ca...

The signal is on D7 so a quick way to check timing out of an operation within device driver code (rather than reading ZX8302). I have no schematic of SGC, I tried looking closely at pictures of Tetroid's PCB's but can't see if B13 (CSYNCL) is used. Puzzled why SGC would use CSYNCL for DRAM refresh w...

I don't understand how VSYNCH (20mS) connected only to FLP chip has anything to do with memory refresh? (YMMV) Is it connected to the FLP chip? That seems odd if it is. Yes, I have checked both Nasta's and Tetroid's schematics of Gold Card. (Something to do with locking data separator to crystal, o...

I don't understand how VSYNCH (20mS) connected only to FLP chip has anything to do with memory refresh? (YMMV)

The Gold card and Super Gold card use the QL display VSYNCH line for the floppy driver chip DP8473 (pin 35 DSKCHG/RG). It looks like your display is suffering from a synch problem. I would look at QL expansion bus pin B15 on the QL and the SGC. I can't think of anything else that would cause the pro...

The internal RAM chips are accessed by the CPU through IC19,20,21. They are also frequently read by IC22 ZX8301 to produce the display, by which means they get regularly refreshed (as required for DRAM chips). See: http://www.dilwyn.me.uk/docs/hardware/QLissue6.pdf IC19,20,21 are known culprits for ...

Perhaps, I've only tried it without sync job a few dozen times, although I am running Lubuntu and not Windows. On Lubuntu 21.04 you can get at the config file to stop special keys being trapped (/home/david/.config/openbox/lxqt-rc.xml). But ALT+CTRL+SHIFT+TAB is not used anyway, don't know whether t...

That's very useful, thanks, Per. Whats puzzling is that I don't need to use EMU_SYNCSCRAP, to start a job, it just appears to work without it.

BTW anyone else lost the use of reset with ALT+CTRL+SHIFT+TAB when using wireless keyboard?

Just ordered a Teensy++ 2.0, they look as if the are getting rare now, the one I got was last from vendor, PJRC.com is now out of stock for good? (https://www.pjrc.com/store/teensypp.html), Nice to see the AT90USB1286 is still plentiful though, I don't suppose it would be difficult to make a QL spec...

Lau said he has all his QL stuff in a lockup somewhere. It might still boot, who knows? I still have mine, bought in 1990 (£445, at the time I decided to go for MHD instead of a Atari Falcon - I didn't like the GEM front end - regret it now :( ). It still works OK (very noisy though) , Lau might ye...