The Sinclair QL Forum

Well, even if this is correct, I dont think that was the reason to use it. I don't know the price of the 6821 in the 80's but there is TTL chips like the 74LS245 that can do the same job, for a fraction of the cost, and that reduce the code need for use the sound chip, now you need to do one o more...

aalea wrote:I put the gerber, schematic and other things here: https://github.com/alvaroalea/QL_QsoundQprint_clone

BTW the 6821 PIA reduces the noise that would otherwise be heard from AY if its data lines were directly connected to QL data bus.

That it works with earlier SMSQ/E surely must mean CPU is OK. Perhaps the fact you have full 68040 installed (not expected EC version) may possibly be the root cause ?

Latest v3.38 (31/10/21) of SMSQEQXL.EXE works fine with keyboard on my QXL 1.

Chr$ wrote:A connection to RESET on the CPU you mean? That shouldn't be a problem.

Yes, probably to pin 1.

I was trying to think if there was a way to force into 128K mode by doing quick double reset. Probably impossible to reliably detect

In addition to spare input pin (for enable switch) it will require RESET (to clock enable/disable condition through only on reset). Something I forgot to mention Chr$ :oops: aalea if it is OK for you to create JED for changes required please do. It'll probably be quicker than it'll take me to come u...

Also SC414423RC75 is MC68EC060RC75.

You just beat me to it

Also at https://morloch.hd.free.fr/smsq/Area03/RBarc.lzh

I have an archiver file called plot_arq lurking on my hard disk. Long since forgotten what it was. Anyone know what program could be used to unarchive it? Have tried the various _arc decompressors on my site and Archivers Control Panel, none seem to work. What are the first dozen or so bytes (ASCII...

Is it integrated with QDOS? No not yet, because EXTINT isn't always quick enough to respond. The links allowed level 5 interrupt use (with QL H/W and S/W fix), but that's a bit of a hack for myself. Which is why I was looking out for some reasonably priced SC28L92. It had mostly been used for MIDI ...