What did you see when you checked the power to the DRAm area? Was it nice and smooth, or dipping? What about at the 8302?
The inconsistency of this is similar to a QL I repaired many years ago where the DRAM wasn't refreshing properly, and it turned out to be a power/bounce problem.
Search found 2477 matches
- Fri Apr 17, 2020 3:33 pm
- Forum: Hardware
- Topic: 5.25" floppy drive configuration
- Replies: 27
- Views: 1131
What is the situation with termination resistors on the drives? If they're terminated incorrectly, they may accept "motor on" signals but not recognize data properly. On 5/25" drives, usually only the data lines were terminated on the last drive, with a resistor pack.
May I propose thinking about this in a slightly different way? What if instead of a flash IC (20 year retention guarantee) you used a 128K low power SRAM and CR2032 battery as back-up power? In standby, the SRAM would retain contents using microAmps. The battery would last 15 or 20 years. If you spl...
I have programmed flash off the QL bus, during multi-tasking, without problems. If you recall my idea a few years ago of having multiple CPUs mapped through dual port SRAM to areas of the QL's memory map, I did a fair amount of work on it. I ended up using a small flash as a persistent system-progra...
- Fri Mar 27, 2020 4:05 am
- Forum: General QL Chat
- Topic: Comparing Sinclair QL to Commodore 64
- Replies: 27
- Views: 1087
If I had to pick a machine that was most line the QL, I would pick the Coleco Adam. Similarities: Both have two CPUs. The Adam 2nd CPU, used for system IO and memory management, is a 6801 - a small ROM microcontroller version of the 6800. In the QL, it's an 8049. Both communicate through an internal...