Search found 24 matches

by MaestroSoftware
Sat Jun 12, 2021 3:04 pm
Forum: Dragon Hardware
Topic: RACE Electronics Peripherals
Replies: 28
Views: 11290

Re: RACE Electronics Peripherals

I'd be surprised if it doesn't respond to other addresses apart from $FEFF. I'm going to check on this asap. I found out that READING $feff switches the expansion board to slot 2, but didn't detect any other strange behaviour yet. I need to know a way to assert that [the Race expansion] is plugged ...
by MaestroSoftware
Wed Jun 02, 2021 12:00 am
Forum: Dragon Hardware
Topic: Diagnosing and repairing a faulty 64
Replies: 4
Views: 931

Re: Diagnosing and repairing a faulty 64

Ok, replacing the CPU fixed the issue. The most likely cause of that failure was +12V spilling on the NMI line and destroying some internal NMI logic in the 6809. Actually, the old CPU worked fine, until it encountered an NMI interrupt. Actually, when replacing the CPU with a 6309, the display got j...
by MaestroSoftware
Mon May 31, 2021 9:55 pm
Forum: Dragon Hardware
Topic: Tandy Multipak and the Dragon
Replies: 1
Views: 438

Tandy Multipak and the Dragon

I read on this forum that the original Tandy Multipak is compatible with the Dragon (I know Pere's DosPlusExtender supports it). I also read that Coco3-modified Multipaks are not compatible with the Dragon. Is that true? Why?

Thanks

Philippe
by MaestroSoftware
Sun May 30, 2021 2:12 pm
Forum: Dragon General
Topic: A DOSPlus Extender for Drivewire & CoCo-SDC
Replies: 109
Views: 41387

Re: A DOSPlus Extender for Drivewire & CoCo-SDC

Yep, bluearcus, that is what I was referring to when writing "maybe you use the special capability of the MPI to select a different slot for CTS (ROM) and SCS (floppy disk controller I/O addresses) " However: 1) In the source code of DosPlusExtender, Pere seems to copy the upper nibble to the lower ...
by MaestroSoftware
Sat May 29, 2021 11:07 pm
Forum: Dragon General
Topic: A DOSPlus Extender for Drivewire & CoCo-SDC
Replies: 109
Views: 41387

Re: A DOSPlus Extender for Drivewire & CoCo-SDC

I was starting to rewrite the parts of DosPlusExtender that apply to mpi in order to detect the Race expansion and make it behave like an MPI. But there's something fundamental I don't understand: does DosPlusExtender allow you to work simultaneously with physical floppies and CocoSDC on a Dragon 32...
by MaestroSoftware
Fri May 28, 2021 9:13 pm
Forum: Dragon Hardware
Topic: Dragon expansions - FF00 page ports
Replies: 8
Views: 1269

Re: Dragon expansions - FF00 page ports

I tried to organize this in the wiki as a table : http://worldofdragon.org/index.php?titl ... _ADDRESSES
by MaestroSoftware
Thu May 27, 2021 1:32 pm
Forum: Dragon General
Topic: A DOSPlus Extender for Drivewire & CoCo-SDC
Replies: 109
Views: 41387

Re: A DOSPlus Extender for Drivewire & CoCo-SDC

I plan to scan my Race Electronics manual for upload to the archive, but basically : whereas 4 bits are used in address $FF7F for the MPI (2 bits for SCS , 2 bits for CTS), for Race, you just POKE 0, 1, 2 or 3 to $FEFF - and no info can be read from that address
by MaestroSoftware
Thu May 27, 2021 7:00 am
Forum: Dragon General
Topic: A DOSPlus Extender for Drivewire & CoCo-SDC
Replies: 109
Views: 41387

Re: A DOSPlus Extender for Drivewire & CoCo-SDC

Tony: yes indeed I could make the assumption that the CocoSDC is in slot 0, and the FDC in slot 1. Not very elegant, but allows for some quick coding. Pere: I'm afraid values to be POKEd in FF7F are not the same as FEFF (see https://www.lomont.org/software/misc/coco/Lomont_CoCoHardware.pdf, p.59) An...
by MaestroSoftware
Tue May 25, 2021 6:56 pm
Forum: Dragon Hardware
Topic: Diagnosing and repairing a faulty 64
Replies: 4
Views: 931

Re: Diagnosing and repairing a faulty 64

Hi Stewart, Thank you for these pointers. I just tested with the only non-Dos cartridge that I own: Cyrus Chess. I don't know if it autostarts by having DK at $C000 or through FIRQ/CART but it worked long enough for the Dragon to beat me, once more n ;-) The schematic of the Coco-XT MFM controller i...
by MaestroSoftware
Sun May 23, 2021 8:40 pm
Forum: Dragon Hardware
Topic: Diagnosing and repairing a faulty 64
Replies: 4
Views: 931

Diagnosing and repairing a faulty 64

My beloved D64 (with Dragonplus) is sick, possibly due to my experiments with my MFM hard disk controller. On the very day I got my first victory (reading sector 0 from the hard drive), my CocoSDC stopped working reliably, sometimes hanging when I accessed the virtual disks; more often hanging at bo...