The Sinclair QL Forum

If you have Hermes you can use P20, P23 and P26 as inputs and/or outputs (see Hermes manual).

(IMHO you'd need to buffer them for output, pins are quasi-bidirectional: low is 300ohm to 0V, weak high is 50Kohm to +5V, strong high is 5Kohm to +5V for 272nS when set)

Nice job. When I got my Q40 back in 1999 I was keen to try MOD playback, but the 20000/sec interrupt overhead put me off (IIRC at the time AD1848 chip was cheaper than DAC used :( ). Just received a YM2608 and YM2610 from China (quick 14 day delivery now!). They both contain AY type PSG, FM/OPN and ...

Sorry, but why bother? There is no software with which the board needs to be compatible with and any newly built solution should feature at least a real crystal for AY clock and two AY chips IMHO. I only contentplated this, mainly to repair my Qsound board. I have part done a Qsound Schematic, but ...

I did a rough schematic of QSound when PCB was posted. From what I saw it uses 750kHz E clock (60/40 duty). The AY data sheets specifies minimum 1MHz and 50/50 duty. But Bumble bees fly... As I wrote the QSound software calculates its frequencies for a 1.5Mhz base clock, so the E signal is only par...

mk79 wrote:Does anybody know how the clock for the AY chip is derived? I don't understand this from the posted PCB photos.

I did a rough schematic of QSound when PCB was posted. From what I saw it uses 750kHz E clock (60/40 duty). The AY data sheets specifies minimum 1MHz and 50/50 duty. But Bumble bees fly...

If you are one of the lucky ones with a SGC with PAR port...

Edit : see later in thread for latest AYplayer version

One of the saving graces of using an emulator I was glad of recently was being able to snapshot the QXL.WIN file and immediately recover stuff using a Linux hex editor (text search, cut & paste). I was swapping between an earlier working source file and new version to wring out bugs in some code...

Be nice to see how he programmed the GALs

Oh, and it would be a pity if all the work he must of done disappears

Deja vu ? viewtopic.php?f=2&t=909&hilit=CLA2345

No, still the same! I've had similar problems. The first (sudden movement of pointer to display extremes) was due to a flakey moulded 9D connector on the lead of the mouse - the socket clasps were too weak, so the connection was unreliable. The solution was to cut it off and use soldered socket. Th...