Search found 204 matches

by Silvester
Tue Sep 17, 2019 12:59 pm
Forum: Wanted
Topic: Schon keyboard
Replies: 9
Views: 479

Re: Schon keyboard

I replaced the flakey QL membrane keyboard connecter with turned pin sockets. Also replacing Schon lead with a ribbon cable soldered into turned pins, improving reliability. One of the problems with replicating Schon QL keyboard was the fact Schon supplied a very neatly cut out QL top case (along wi...
by Silvester
Sat Sep 07, 2019 9:27 am
Forum: Wanted
Topic: Schon keyboard
Replies: 9
Views: 479

Re: Schon keyboard

Sorry to be contrary, but I have both the PS and the QL Schon keyboards, bought them back in early 1990's and they still are in use today. The PS keyboard has had several cleans of the PCB before eventually the carbon key pads wore thin. Solution was to (painstakingly) stick foil contacts on them (a...
by Silvester
Thu Aug 15, 2019 12:48 pm
Forum: Hardware
Topic: Mod on ULA
Replies: 9
Views: 909

Re: Mod on ULA

Bit of a coincicdence :-) I recently resurrected an old QL motherboard which I had removed the 33k resistors from the ULA (not required when I used QIMI). With no microdrives attached (and no QIMI) I sometimes had trouble getting the cursor to appear after pressing F1/F2. But then I noticed if I wav...
by Silvester
Sat May 25, 2019 9:31 am
Forum: Hardware
Topic: Asymmetric multiprocessing...
Replies: 71
Views: 4722

Re: Asymmetric multiprocessing...

But that can be better done with fast SERial 68681 (one of the reasons why I'm doing it); 31250 MIDI option with opto-isolators along with full SER. You'd have to change the crystal to get the right baud rate out of the 68681, so you would need to use a separate 68681 for MIDI and for serial. If th...
by Silvester
Tue May 21, 2019 3:24 pm
Forum: Hardware
Topic: Asymmetric multiprocessing...
Replies: 71
Views: 4722

Re: Asymmetric multiprocessing...

Oh that reminds me, when I first tried the MIDI interface with a Gold card it was double stepping (as each byte of Z80 code is uploaded it should 'read' back an incrementing address number). Thinking it may be due to GC 68000 not having A0 and it was doing a word access I did a quick remedy by swapp...
by Silvester
Tue May 21, 2019 3:05 pm
Forum: Hardware
Topic: Asymmetric multiprocessing...
Replies: 71
Views: 4722

Re: Asymmetric multiprocessing...

Dave wrote: Have you worked out a schematic, or got clear photos of the MIDI board?. It sounds like it would be a very interesting thing to see. Hmm, the schematic was in http://www.dilwyn.me.uk/docs/hardware/QLperip.zip (was I wot did it). Dave wrote: MIDI has been whispered in my ear more than a ...
by Silvester
Sat May 18, 2019 2:09 pm
Forum: Hardware
Topic: Asymmetric multiprocessing...
Replies: 71
Views: 4722

Re: Asymmetric multiprocessing...

There was the humble Miracle MIDI interface where the Z80 waited for OS code to be uploaded from the ROM port: http://www.dilwyn.me.uk/docs/hardware/QLperip.zip
by Silvester
Tue May 07, 2019 11:48 am
Forum: Hardware
Topic: Issue 8 discussions...
Replies: 125
Views: 12175

Re: Issue 8 discussions...

I'm working on the PCB a little today and will be ordering some prototypes. I have 2-3 people I'd like to send a hardware complete prototype to, so.... If I have Issue 8 work, that takes priority, but if I don't I'll get that PCB updated. Couple of weeks? I've got a couple of SCN68681 (DIP40) on th...
by Silvester
Sat May 04, 2019 9:43 am
Forum: Hardware
Topic: Issue 8 discussions...
Replies: 125
Views: 12175

Re: Issue 8 discussions...

SC28L92... If a driver magically appears.... Ah, it would be some sort of sorcery to write a driver without the device/hardware :D Thanks for expressing interest, Silvester. More than interest, I would be quite happy to write the driver (since no one else has come forward). The only problem is wher...
by Silvester
Thu May 02, 2019 12:44 pm
Forum: General QL Chat
Topic: What makes the OS for QL any better, different, unique ?
Replies: 24
Views: 2321

Re: What makes the OS for QL any better, different, unique ?

Arnould wrote:Until Tony one day explained the cure... or I was ready to understand :) If interested I can also write about this.

yes please :)