Search found 943 matches
- Mon Jun 03, 2024 1:02 pm
- Forum: Hardware
- Topic: Connecting a uC (PIC) to the QL
- Replies: 12
- Views: 330
Re: Connecting a uC (PIC) to the QL
Hi again fuasn! Just wanted to add a small additional consideration that is sometimes overlooked and, in any case becomes relevant dependent upon which address lines you are decoding... The 68k will also issue what looks like a valid memory access during its ACKnowledge to an Interrupt. You should a...
- Mon Jun 03, 2024 12:03 am
- Forum: Hardware
- Topic: Connecting a uC (PIC) to the QL
- Replies: 12
- Views: 330
Re: Connecting a uC (PIC) to the QL
Hi there! You are correct. We used to have to rely on a fast transistor to drive DSMC# High upon recognising it's own address and thus 'steal' it from the 8301. Today's modern CPLDs are both fast enough and provide enough current drive to achieve the same effect before the 8301 detects DS#. That sai...
- Sat May 25, 2024 12:17 pm
- Forum: Hardware
- Topic: Faulty (video) ram
- Replies: 25
- Views: 760
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: 700
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: 700
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: 50
- Views: 8107
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: 487
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: 2268
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: 487
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: 608
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...