Search found 934 matches
- Thu May 09, 2024 5:30 pm
- Forum: Hardware
- Topic: Recommended maintance & MDV ULA Problem
- Replies: 7
- Views: 445
Re: Recommended maintance & MDV ULA Problem
Hi Martin For what its worth, attached here is an image from an old capture-trace I took of the MDV signal lines at the very start of a 'DIR mdv3_', as seen at the MDV-Extension port. MDV3 was a ZX unit, attached externally to the QL, as you'd imagine. MDV3_trace.png A few points: a) I was wrong abo...
- Thu May 09, 2024 5:03 pm
- Forum: Hardware
- Topic: Recommended maintance & MDV ULA Problem
- Replies: 7
- Views: 445
Re: Recommended maintance & MDV ULA Problem
Hi again Martin Not sure how a multimeter would.ipact your readings, but I regularly use my simple/cheapo USB digital analyser with PulseView software to monitor those signals. Monitoring the Erase and WP lines requires a bit of circuitry to prepare the signals for capture, but the 'sort of digital'...
- Tue May 07, 2024 11:10 am
- Forum: Hardware
- Topic: Recommended maintance & MDV ULA Problem
- Replies: 7
- Views: 445
Re: Recommended maintance & MDV ULA Problem
Hi Martin! No harm in replacing the Cap in the reset cct, I'm sure. If the problem goes away after a further reset, it could be the 15MHz oscillator driving the ZX8302 ageing and not stabilising 'quickly enough.' But that's just speculation. As for the method used to select each MDV unit, I think I ...
- Mon May 06, 2024 3:07 pm
- Forum: Hardware
- Topic: Recommended maintance & MDV ULA Problem
- Replies: 7
- Views: 445
Re: Recommended maintance & MDV ULA Problem
Hi Martin! I've never had a problem with RESET that required that Cap to be replaced - when I have hitn problems with reset, it was either down to the ZX8302 or something more fundamental with the main ZX8301, but replacing the Cap is a simple and cheap enough operation to eliminate it. I am in the ...
- Wed May 01, 2024 8:22 pm
- Forum: Hardware
- Topic: CST Ram Plus eproms - CST QDisc v4 issue
- Replies: 15
- Views: 802
Re: CST Ram Plus eproms - CST QDisc v4 issue
Hi all! If indeed the v4 board uses the 'scrambled' method for data and/or address lines and if the ROM was programmed in a std programmer from a straight image, then therein would certainly lie one probable cause... A quick check would be to PEEK_W from Basic the base address where the CST ROM is e...
- Wed May 01, 2024 12:16 am
- Forum: Hardware
- Topic: QL-SD jumperable
- Replies: 12
- Views: 2931
Re: QL-SD jumperable
Ah, OK. Bit of a schlep from London...
I have the equipment needed to reflash the QL-SD device and have made the same change on one of mine successfully.
PM me and perhaps we can figure out how cost effective shipping to/fro would be.
Or are you planning to attend the Dormagen event in May?
I have the equipment needed to reflash the QL-SD device and have made the same change on one of mine successfully.
PM me and perhaps we can figure out how cost effective shipping to/fro would be.
Or are you planning to attend the Dormagen event in May?
- Tue Apr 30, 2024 10:59 pm
- Forum: Hardware
- Topic: QL-SD jumperable
- Replies: 12
- Views: 2931
Re: QL-SD jumperable
Where are you afx?
(Just roughly, not asking for you to reveal anything sensitive!)
(Just roughly, not asking for you to reveal anything sensitive!)
- Fri Apr 26, 2024 1:00 pm
- Forum: Prospective Members
- Topic: Is QUANTA stil alive / accepting members?
- Replies: 51
- Views: 67301
Re: Is QUANTA stil alive / accepting members?
Just to update - Mr Southern was in touch yesterday via email - looking forward to recieving the new magazine!
Re: OqtaDrive
Well done, Alex!
- Tue Apr 23, 2024 4:07 pm
- Forum: Hardware
- Topic: SOLVED ntsc sinclar ql schematics ??
- Replies: 15
- Views: 1103
Re: ntsc sinclar ql schematics ??
Hi again Peter! To be fair, the UK keyboard was already pretty much based on the US layout - something I was surprised to discover when developing the extra language maps for the Qbase :-) Did you finish any of them? No, not yet. I developed a flexible framework to support up to 8 distinct, user-sel...