Search found 1446 matches

by Dave
Sun Nov 12, 2017 4:37 pm
Forum: Hardware
Topic: Random hardware ideas!
Replies: 76
Views: 5757

Re: Random hardware ideas!

The only reason I can imagine for not wanting to use a QL-SD is the need to use an older QL OS than Minerva. I can't think of a single reason why a person would want to do that. I will send you (Doug) a backplane, Q-Buck regulator (it will help keep the PSU and QL cool when you run everything off th...
by Dave
Thu Nov 09, 2017 5:07 pm
Forum: Hardware
Topic: Random hardware ideas!
Replies: 76
Views: 5757

Re: Random hardware ideas!

Hi guys, Dave do you have any more backplanes available? I have an old Gold Card and the modern QubIDE without a passthrough - I'm presuming with your backplane I'd be able to attach both at one, allowing for simultaneous floppy and hard disk action!? Or would it be too tight with the GC? I can mak...
by Dave
Thu Nov 09, 2017 5:05 pm
Forum: Hardware
Topic: Tetroid interfaces hardware info
Replies: 40
Views: 2925

Re: Tetroid interfaces hardware info

Tetroid, what would happen if you to make the backplane and buffer card a single PCB? The elimination of 2 DIN connectors would cut costs, and signal quality would be improved. It would also be more mechanically stable.
by Dave
Tue Nov 07, 2017 12:04 am
Forum: Hardware
Topic: Replacement PSU for US Sinclair QL
Replies: 2
Views: 183

Re: Replacement PSU for US Sinclair QL

PM me your mailing address and I'll mail you one, within the US.
by Dave
Wed Oct 25, 2017 4:35 pm
Forum: Hardware
Topic: Random hardware ideas!
Replies: 76
Views: 5757

Re: Random hardware ideas!

I looked at the propeller too for a while.

Between us, Peter/Derek and Tetroid, there's going to be lots of stuff to shove in those cases. A simple keyboard matrix to PS/2 adapter would get the Q68 into the QL case.
by Dave
Fri Oct 13, 2017 12:35 am
Forum: General QL Chat
Topic: Magnentic Scrolls tapes rescued
Replies: 25
Views: 2087

Re: Magnentic Scrolls tapes rescued

Cristian wrote:In my country is possible to buy 5 kilos bags of cat litter made of pure silica gel for 2-3 euros ;)


Maybe you should spend less on cat litter and more on fixing your logo, which keeps rebooting but never reaches a prompt. It's, just, so WRONG! :P

*OCD*
by Dave
Tue Oct 10, 2017 7:13 pm
Forum: Hardware
Topic: QL upgrade versus Q68
Replies: 67
Views: 5922

Re: QL upgrade versus Q68

Don't bring me into this! I am currently working with someone on a general purpose PIC that can use any HID USB mound and keyboard and convert them to differential mouse and 8 pin byte of keypress plus shift/tab/alt/etc for general purpose use on embedded designs... They're a retro Commodore person,...
by Dave
Fri Oct 06, 2017 6:21 pm
Forum: Hardware
Topic: Microdrive Unit Design
Replies: 92
Views: 5762

Re: Microdrive Unit Design

I designed a microdrive replacement PCB that resolved/ameliorated some of these issues on the analogue side, but it didn't provide much benefit - though it did make a lot of unreadable cartridges recoverable. I'm sure by just mentioning it, Tetroid will release a much improved version within a few w...
by Dave
Fri Oct 06, 2017 6:18 pm
Forum: Hardware
Topic: Microdrive Unit Design
Replies: 92
Views: 5762

Re: Microdrive Unit Design

Hehe... That didn't really help. Let me try again another way. The tape signal during read is AC coupled, as read by the head. Only state changes are readable. Steady state signals quickly revert to zero. The more tape a transition occurs over, the more ambiguous the tipping point is and the more vu...
by Dave
Fri Oct 06, 2017 6:09 pm
Forum: Hardware
Topic: Microdrive Unit Design
Replies: 92
Views: 5762

Re: Microdrive Unit Design

Tobias,

It's near the lower limit. It's not the charge embedded into the tape that matters, but the crispness of the change of state. On playback, the sharpness of that transition is what is read. On microdrives, the transition is nearer the lower boundary.

I hope this is clearer.

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