Search found 1333 matches
- Tue May 28, 2024 5:58 pm
- Forum: Hardware
- Topic: MicroP Controller with Minerva Issue
- Replies: 15
- Views: 262
Re: MicroP Controller with Minerva Issue
possible issue with the edge connector (like a pin that's bent and shorting out maybe?)
- Tue May 28, 2024 5:07 pm
- Forum: Hardware
- Topic: MicroP Controller with Minerva Issue
- Replies: 15
- Views: 262
Re: MicroP Controller with Minerva Issue
ah - so the JM and Minerva ROM's are in 2 different QL's ?
- Tue May 28, 2024 4:13 pm
- Forum: Hardware
- Topic: MicroP Controller with Minerva Issue
- Replies: 15
- Views: 262
Re: MicroP Controller with Minerva Issue
The only possibility I can think if is if your Minverva also has TK2, and the floppy interface is set for the ROM port address...
- Sat May 25, 2024 2:32 pm
- Forum: Hardware
- Topic: Faulty (video) ram
- Replies: 25
- Views: 667
Re: Faulty (video) ram
Nice one
- Sat May 25, 2024 2:11 pm
- Forum: Hardware
- Topic: Faulty (video) ram
- Replies: 25
- Views: 667
Re: Faulty (video) ram
Well done on the progress with the DRAMS - so now probably just a single faulty chip?
- Sat May 25, 2024 2:11 pm
- Forum: Hardware
- Topic: Faulty (video) ram
- Replies: 25
- Views: 667
The QL motherboard has pin 1 and pin 28 wired to 5V - so the 'expected' A15 signal is not on that pin - instead it's used as a chip select for the ROM's - the ROM's in the QL ROM set - one is active high and one active low - so A15 decodes whether lower 32K or upper 16K rom are selected. Either ROM ...
- Wed May 22, 2024 9:14 pm
- Forum: Hardware
- Topic: Faulty (video) ram
- Replies: 25
- Views: 667
Re: Faulty (video) ram
that could be down to either a ram chip not being writable (Data in on the RAM shorted or open circuit), or to a shorted or open address line on the DRAM chips - the regular pattern also suggests something like this. Such problems are hard to find. As you have surmised - the upper and lower banks ar...
- Mon May 20, 2024 11:28 pm
- Forum: General QL Chat
- Topic: Anouncement for the 40th Anniversary of the Sinclair QL in Dormagen (Germany)
- Replies: 50
- Views: 7718
Re: Anouncement for the 40th Anniversary of the Sinclair QL in Dormagen (Germany)
those current draws are favourable. Letterbox - just that a keyboard and LCD screen combo may be a good way to do this - as it's one single case to make - no hinges. The letterbox LCD screens are available with HDMI input - but the resolutions are a bit strange - they are usually 400x1280 or 480x192...
- Mon May 20, 2024 9:26 pm
- Forum: General QL Chat
- Topic: Anouncement for the 40th Anniversary of the Sinclair QL in Dormagen (Germany)
- Replies: 50
- Views: 7718
Re: Anouncement for the 40th Anniversary of the Sinclair QL in Dormagen (Germany)
Thoughts from the 40th QL Celebration. It was a late decision for me to attend the 40th Anniversary celebration in Dormagen, but I am glad that I did make that decision. Having been in and out QL ownership over most of those years, but strangely always having a couple of Sinclair products in my hous...
- Mon May 20, 2024 8:51 pm
- Forum: The Off-Topic Section
- Topic: Z88 power supply
- Replies: 15
- Views: 672
Re: Z88 power supply
I've used 7V without a problem, not sure about 7.5V - It is dropped by one diode forward voltage (about 0.6-0.7 vols), and feeds the circuit that would normally see the 6V from the batteries. Very fresh batteries could provide close to 1.6V each - giving a voltage of 6.4 against the 6.9 you would se...