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by Dave
Wed Aug 23, 2017 12:04 am
Forum: Hardware
Topic: Sinclair QL - blank screen.... HeLp!
Replies: 20
Views: 665

Re: Sinclair QL - blank screen.... HeLp!

Don't do this unless you're using a Fluke or other quality multimeter. Some cheap multimeters put the whole battery voltage across the pins to measure resistance, and that might be 9V.

Very. Bad. Things.
by Dave
Wed Aug 23, 2017 12:01 am
Forum: Hardware
Topic: Odd keyboard issue
Replies: 5
Views: 95

Re: Odd keyboard issue

This is not uncommon. Often, it takes as little as a too-entusiastic cleaning with a q-tip to push the spring clip back and cause a weak connection. I usually solve this by putting a bit of tape across the back of the membrane connector. That makes better contact AND reinforces it. I would have used...
by Dave
Mon Aug 21, 2017 11:12 pm
Forum: General QL Chat
Topic: The Future of the QL Wiki
Replies: 121
Views: 9165

Re: The Future of the QL Wiki

I'm, as I've been rightly told, not in a good position to handle this myself right now. My last heart surgery was on Saturday :| it went quite well, thanks for asking :) That said, I'm eager to support any endeavor. If anyone's interested and just wants a back up editor/fixer/researcher, I have the ...
by Dave
Mon Aug 21, 2017 11:09 pm
Forum: Hardware
Topic: Connecting the QL to modern TVs
Replies: 10
Views: 438

Re: Connecting the QL to modern TVs

If someone will produce the code, I'll happily fund making the hardware.
by Dave
Sun Aug 20, 2017 11:20 pm
Forum: Hardware
Topic: Connecting the QL to modern TVs
Replies: 10
Views: 438

Re: Connecting the QL to modern TVs

It's not latency that causes the problem, but the sheer bandwidth of writes to video RAM is huge.
by Dave
Sun Aug 20, 2017 7:17 pm
Forum: Hardware
Topic: Connecting the QL to modern TVs
Replies: 10
Views: 438

Re: Connecting the QL to modern TVs

The ZX-HD works well and decodes and copies writes to video RAM, which is a tiny area run at slow speed in the ZX80/81. I have high hopes the Pi could do this, but Nasta is unequivocal - the Pi GPIO isn't fast enough. It might well be on the Pi4, as that is one area that didn't really improve betwee...
by Dave
Sun Aug 20, 2017 5:49 pm
Forum: Hardware
Topic: Connecting the QL to modern TVs
Replies: 10
Views: 438

Re: Connecting the QL to modern TVs

This is very expensive for what it is. The entire board has a value including design costs of maybe £15. There are a few ICs that can do RGB to composite/s-video but they for practical purposes just duplicate existing functionality the QL already has. We looked at this and decided it wasn't worth do...
by Dave
Wed Aug 16, 2017 10:49 pm
Forum: Hardware
Topic: Issue 8 and WiFi
Replies: 37
Views: 2249

Re: Issue 8 and WiFi

The card would run the TCP stack for you. You access it like a Hayes modem, tell it what IP you want to connect to, etc. It supports encryption for you too, and it would be programmable in its own right to extend its functionality. It has a dozen or so GPIO pins, dual core CPU and a good chunk of R...
by Dave
Wed Aug 16, 2017 10:48 pm
Forum: Hardware
Topic: Issue 8 and WiFi
Replies: 37
Views: 2249

Re: Issue 8 and WiFi

MartynHill wrote:That works for me and opens the possibility of some general purpose I/O as well.

I am interested. Any idea of eventual cost?

M.


A serial port version would come in around £40. An internal version would be technically cleaner and be around £60?

Wild guess.
by Dave
Tue Aug 15, 2017 9:09 pm
Forum: Hardware
Topic: Issue 8 and WiFi
Replies: 37
Views: 2249

Re: Issue 8 and WiFi

The card would run the TCP stack for you. You access it like a Hayes modem, tell it what IP you want to connect to, etc. It supports encryption for you too, and it would be programmable in its own right to extend its functionality. It has a dozen or so GPIO pins, dual core CPU and a good chunk of RA...

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