Search found 851 matches

by Peter
Mon Oct 21, 2013 9:21 pm
Forum: For Sale
Topic: Sinclair QL Floppy Disk Interfaces
Replies: 47
Views: 11462

Re: Sinclair QL Floppy Disk Interfaces

As for my knowledge: Obviously it was not sufficient to foresee the problems QL-SD would suffer from. I was more used to newer designs like the Q68 and Q60, where you have decent signal quality due to adequate routing and ground planes. The QL motherboard was never designed to satisfy >300 MHz logic...
by Peter
Mon Oct 21, 2013 8:42 pm
Forum: Hardware
Topic: QL-SD card project
Replies: 43
Views: 13654

Re: QL-SD card project

Yes, I know, it's never that simple :-( Mark And here's one of the examples why: Noisy low-level address signal at 1.2V during ROMOE active-high. (Scope has persistance on, address signal on top.) To deal with this kind of noise, the adress line is sampled at ROMOE rising edge, where there is less ...
by Peter
Mon Oct 21, 2013 7:08 pm
Forum: Hardware
Topic: QL-SD card project
Replies: 43
Views: 13654

Re: QL-SD card project

This picture shows the ROMOE signal on my SuperGoldCard QL, which is used as an imput to QL-SD. The horizontal dotted line is the maximum allowed low level TTL voltage of 0.8V. The measured signal illegally goes up to 1.5V where logic level is low. The oscilloscope has a bandwidth of 60 MHz only, so...
by Peter
Mon Oct 21, 2013 4:42 pm
Forum: For Sale
Topic: Sinclair QL Floppy Disk Interfaces
Replies: 47
Views: 11462

Re: Sinclair QL Floppy Disk Interfaces

This was about a Super Gold Card remake: You can always get a newer model and just port the logic code to the newer chip. On the VHDL level, it's a day's work tops and Altera will have guides (if not porting tools too) to tell you how. Firstly, complex ancient logic code can be hard to port to newer...
by Peter
Sun Oct 20, 2013 1:53 pm
Forum: Links to QL Services and Websites
Topic: Dilwyn's QL Blog
Replies: 3
Views: 3295

Re: Dilwyn's QL Blog

Wow Dilwyn! Cool! :D

Where did you take the picture of the QL-SD mounted inside the QL? Obviously not my desk.

By the way, I think I said "good chance", not "very good chance". After Adrian gave up, lets not be over-optimistic ;)
by Peter
Fri Oct 18, 2013 11:32 am
Forum: General QL Chat
Topic: A seat in the lifeboat
Replies: 17
Views: 6398

Re: A seat in the lifeboat

Over-simplified answer: If you have only 128 KB RAM or don't want to open the QL, it is the microdrive emulation. If you want speed or dislike boards protruding from the QL, it is the QL-SD. ;) Except for 3 or 4 persons, it's only theoretical, as both devices are not for sale yet. I made a little pr...
by Peter
Mon Sep 23, 2013 11:32 am
Forum: General QL Chat
Topic: A seat in the lifeboat
Replies: 17
Views: 6398

Re: A seat in the lifeboat

For Info: The QL-SD is an internal solution with two boards. One of them plugs into one of the internal ROM sockets, similar to Minerva, and the other one can replace one of the internal microdrives, so the SDHC card can be inserted just like a cartridge. However, the QL-SD does not required to repl...
by Peter
Wed Sep 18, 2013 1:33 pm
Forum: General QL Chat
Topic: A seat in the lifeboat
Replies: 17
Views: 6398

Re: A seat in the lifeboat

Thank you Tobias.

You are right about mass storage for the original QL, but I worry that lack of screen support will also bring it down. You would need a video card for the original QL - a project which could end up even bigger than doing the remaining Q68 work.
by Peter
Sun Sep 15, 2013 1:15 am
Forum: General QL Chat
Topic: A seat in the lifeboat
Replies: 17
Views: 6398

Re: A seat in the lifeboat

I was not aware of Petri Pellinen's device and did not mean to call it's success "unlikely".
My remark was related to the QL signal quality problems encountered during QL-SD development.
Good luck to you Petri!
by Peter
Sat Sep 14, 2013 9:05 pm
Forum: General QL Chat
Topic: A seat in the lifeboat
Replies: 17
Views: 6398

Re: A seat in the lifeboat

Just having native TCP/IP support would not provide an original QL with reasonable internet connectivity, as the QL has only the serial port. One would want ethernet, and at the moment, only Q40 and Q60 have a hardware solution for that. Unfortunately, as programmable logic chips become faster and l...