Search found 941 matches
- Sat May 25, 2024 12:17 pm
- Forum: Hardware
- Topic: Faulty (video) ram
- Replies: 25
- Views: 466
Re: Faulty (video) ram
Hi fuasn! Just a thought about your probing strategy - for those ICs socketed already, aim to test both with and without them in circuit when you test for shorts. Sometimes what you end up measuring with ICs still in circuit is their own inherent impedance to Gnd or Vcc, which, whilst a valuable dat...
- Tue May 21, 2024 2:19 pm
- Forum: Hardware
- Topic: Problem after installing minerva
- Replies: 16
- Views: 595
Re: Problem after installing minerva
Interesting development, Fred :-) As for the placement of the two original ROMs, actually it doesn't matter at all which of the two sockets they are fitted in to as both have exactly the same pinout. The Masked ROMs take this in their stride due to the way the Chip select logic is enabled in each RO...
- Mon May 20, 2024 3:43 pm
- Forum: Hardware
- Topic: Problem after installing minerva
- Replies: 16
- Views: 595
Re: Problem after installing minerva
Halo Fred! From what you describe, either something was 'disturbed' when removing/replacing/switching back the two ROMs, the legs weren't seated correctly in their sockets or, (hopefully not), the 8301 ULA has died coincidentally with your upgrade attempt. Unlikely to be a DRAM failure, though the B...
- Sun May 19, 2024 1:17 pm
- Forum: General QL Chat
- Topic: Anouncement for the 40th Anniversary of the Sinclair QL in Dormagen (Germany)
- Replies: 49
- Views: 7268
Re: Anouncement for the 40th Anniversary of the Sinclair QL in Dormagen (Germany)
Hello everyone! I just wanted to share an initial, personal review of this weekend's meeting in Dormagen: Well, what a terrific event! Detlef is to be commended for his excellent organisation and generosity in bringing us together! For many years I have exchanged emails and posts via the various for...
- Tue May 14, 2024 1:59 pm
- Forum: Hardware
- Topic: Video cable compatible with all Scart TVs
- Replies: 8
- Views: 393
Re: Video cable compatible with all Scart TVs
Hi again Robbizz!
OK, so all I personally can think-of is that this monitor doesn't like the QL's 'over-scan' timing and is struggling to sync properly.
(BTW, as you observed, I misnamed the SCART Video-In pin - yes,its pin-20, not 18.)
Keep us posted
OK, so all I personally can think-of is that this monitor doesn't like the QL's 'over-scan' timing and is struggling to sync properly.
(BTW, as you observed, I misnamed the SCART Video-In pin - yes,its pin-20, not 18.)
Keep us posted
- Sun May 12, 2024 10:01 am
- Forum: Compatibles Corner
- Topic: Thor XVI - Request for documentation...
- Replies: 12
- Views: 2053
Re: Thor XVI - Request for documentation...
Good morning all - and Happy Mother's Day to our mainland European friends :-) Just to close the loop on this request - after many hours of unpacking, searching for, reviewing and then scanning-in the Thor Technical Manual, Urs Koenig has very generously made available the FULL technical manaul that...
- Sat May 11, 2024 8:18 pm
- Forum: Hardware
- Topic: Video cable compatible with all Scart TVs
- Replies: 8
- Views: 393
Re: Video cable compatible with all Scart TVs
Hi Robbizz! [Edited to correct SCART pin numbering in original post] I've had success creating a number of QL -> SCART cables over time, based more or less on the really useful site: http://www.fruitcake.plus.com/Sinclair/Spectrum128/SCARTCable/Spectrum128SCARTCableQL.htm I guess you might have used...
- Thu May 09, 2024 5:30 pm
- Forum: Hardware
- Topic: Recommended maintance & MDV ULA Problem
- Replies: 7
- Views: 541
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: 541
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: 541
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 ...