Curious that it works in a D32. Can't really say much else without seeing a schematic and more detailed measurements.
Assuming you've followed the build instructions to the letter, the ball is very firmly in the court of the supplier and/or designer.
Search found 531 matches
- Fri Jan 14, 2022 2:25 pm
- Forum: Dragon Hardware
- Topic: D64 with new Dragon PSU issue
- Replies: 12
- Views: 11341
- Fri Jan 14, 2022 9:34 am
- Forum: Dragon Hardware
- Topic: D64 with new Dragon PSU issue
- Replies: 12
- Views: 11341
Re: D64 with new Dragon PSU issue
I would use an oscilloscope to see how much ripple there is on the supplies. The fact that it works when more current is drawn suggests one of the supplies is moving to a more stable region, which in turn suggests an incorrect component value. A component value could be incorrect because it was put ...
- Mon Jan 03, 2022 9:45 pm
- Forum: Dragon Hardware
- Topic: Display bars
- Replies: 2
- Views: 2882
Re: Display bars
Hmm, strange one. In my experience, jail bars on Dragons are usually caused by missing bypass caps on the DRAM array, and fitting all eight 100n caps virtually eliminates them. I don't think I've ever seen hum bars on a Dragon. That tends to indicate a fault, particularly if you say 1u caps didn't m...
- Thu Dec 30, 2021 12:07 pm
- Forum: For Sale
- Topic: Blockdown cartridges for sale
- Replies: 2
- Views: 11287
Re: Blockdown cartridges for sale
Love the artwork! Brilliant
- Sat Dec 11, 2021 5:32 pm
- Forum: Hints and Tips
- Topic: Some useful short 6809 routines
- Replies: 2
- Views: 12485
Re: Some useful short 6809 routines
Cool. Thanks for sharing :) There is an old trick for converting a binary digit to ascii hex that is fewer bytes than the branching version: adda #$90 daa adca #$40 daa Also, I wonder how the long multiplication compares with a version that uses 6809 MUL (8x8) to generate the partial products.
- Fri Dec 03, 2021 8:58 pm
- Forum: Dragon Hardware
- Topic: Dragon 64 internal DS1315 RTC board
- Replies: 10
- Views: 11462
Re: Dragon 64 internal DS1315 RTC board
Doesn't RTI spit a dead cycle at the end though?! It does, but the beautiful thing is that it emits the stack pointer during that cycle rather than FFFF :ugeek: Something similar happens to allow say LDA ,X to work. It runs for four cycles: First two cycles are opcode and postbyte, then there is a ...
- Fri Dec 03, 2021 6:33 pm
- Forum: Dragon Hardware
- Topic: Dragon 64 internal DS1315 RTC board
- Replies: 10
- Views: 11462
Re: Dragon 64 internal DS1315 RTC board
Not quite sure where this lies on the filthometer, but one code trick I'm fond of is using rts with a preloaded stack as a fast loop counter or sequencer. A similar thing can be done with puls regs,pc to quickly make a series of function calls with parameters. This approach is nicer because it respe...
- Thu Dec 02, 2021 4:40 pm
- Forum: Dragon Hardware
- Topic: Dragon 64 internal DS1315 RTC board
- Replies: 10
- Views: 11462
Re: Dragon 64 internal DS1315 RTC board
Just some proof of concept code to access the rtc without switching roms.
Should help with getting one of these working in a Dragon 32.
Should help with getting one of these working in a Dragon 32.
- Wed Dec 01, 2021 8:55 pm
- Forum: Dragon Hardware
- Topic: Dragon 64 internal DS1315 RTC board
- Replies: 10
- Views: 11462
Re: Dragon 64 internal DS1315 RTC board
That's some pretty tenacious coding you've pulled off there to access the rtc
- Tue Nov 23, 2021 9:04 pm
- Forum: Dragon General
- Topic: Project 2
- Replies: 56
- Views: 81734
Re: Project 2
The hi score table looks great, and I don't even need to add the qualifier 'for the Dragon'! It definitely captures the arcade feel