Search found 2045 matches
- Tue Oct 22, 2013 2:49 pm
- Forum: Hardware
- Topic: QL-SD card project
- Replies: 43
- Views: 29629
Re: QL-SD card project
Or not break the form factor by adding components, but go back to a classic 5V PLD. Or move things out to the external ROM port, as signal quality seems somewhat better there. The more basic question is, wether to continue tinkering or not. I tend to say, the device should become available as it is....
- Tue Oct 22, 2013 1:01 am
- Forum: For Sale
- Topic: Sinclair QL Floppy Disk Interfaces
- Replies: 47
- Views: 22590
Re: Sinclair QL Floppy Disk Interfaces
I have that too, but isn't it a pain? Characters are hardly legible in 512x256, and single pixels (e.g. at the border) can not be distinguished. Do you use it in 256x256 only?
- Mon Oct 21, 2013 10:19 pm
- Forum: For Sale
- Topic: Sinclair QL Floppy Disk Interfaces
- Replies: 47
- Views: 22590
Re: Sinclair QL Floppy Disk Interfaces
I just wonder all the time, why nobody complains about the lack of flatscreen monitor support for the QL. Storage is obviously important, but I have no idea how to achieve a decent 512x256 QL display nowadays. Do you all press F2 and use TV mode? Or do you all still own working CRT monitors?
- Mon Oct 21, 2013 9:44 pm
- Forum: Hardware
- Topic: QL-SD card project
- Replies: 43
- Views: 29629
Re: QL-SD card project
A question. Could some of the problems be due to a poor ground layout / tracks? Are you seeing a form of "ground bounce" where the voltage drop through the ground is helping to cause the voltage on the signal lines to be out of spec? Mark Yes the QL mainboard ground layout is poor and inv...
- Mon Oct 21, 2013 9:21 pm
- Forum: For Sale
- Topic: Sinclair QL Floppy Disk Interfaces
- Replies: 47
- Views: 22590
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...
- Mon Oct 21, 2013 8:42 pm
- Forum: Hardware
- Topic: QL-SD card project
- Replies: 43
- Views: 29629
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 ...
- Mon Oct 21, 2013 7:08 pm
- Forum: Hardware
- Topic: QL-SD card project
- Replies: 43
- Views: 29629
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...
- Mon Oct 21, 2013 4:42 pm
- Forum: For Sale
- Topic: Sinclair QL Floppy Disk Interfaces
- Replies: 47
- Views: 22590
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...
- Sun Oct 20, 2013 1:53 pm
- Forum: Links to QL Services and Websites
- Topic: Dilwyn's QL Blog
- Replies: 3
- Views: 7103
Re: Dilwyn's QL Blog
Wow Dilwyn! Cool!
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
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
- Fri Oct 18, 2013 11:32 am
- Forum: General QL Chat
- Topic: A seat in the lifeboat
- Replies: 17
- Views: 11257
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...