), and told me that it only works on a Dragon 32 not a Dragon 64.I have a Delta cart, which as far as I can tell works, however since I don't have a manual I have not been able to even get it to format a disk.robcfg wrote:On sunday,a friend brought a Delta Dos cartridge (and I promptly scanned it for the archive
Can anyone confirm this fact? And, is there any way to make it work with a D64?
Another question I have is, may a DragonDos disk be used in a drive managed by a Delta Dos controller, or are they totally incompatible?
If my memory serves me correctly, DeltaDos uses a slightly different disk format than DragonDos. For instance, Delta Dos does not have a backup directory track like DragonDos. Would be interesting to investigate a bit...robcfg wrote:Another question I have is, may a DragonDos disk be used in a drive managed by a Delta Dos controller, or are they totally incompatible?
What a brilliant idea when it was well known that some Dragon 32s couldn't cope with the double speed poke. My Dragon falls into that category and if I had obtained a DeltaDOS controller I would not have been best pleased with the result...prime wrote:From a brief walk through the code, it does seem to do the double speed poke (within the DOS rom), so the dos code will only work when it's in ROM. This should work on a Dragon 64 but only in Dragon 32 mode, but then no Dragon is garantted to work in double speed anyways. Because of this it would be almost impossible to write an OS-9 driver for this controller.
The reason for the double speed poke, is that the Delta controler uses a WD2795 (I think) which has an inverted databus, this means that before *EVERY* bytes is written and after *EVERY* byte is read it must be inverted, this extra processing means that the 6809 cannot keep up with the WD controler unless it's running in double speed mode. A way round this of course would be to invert the whole data block before writing and after reading, so that you where not doing it as you where reading.
It may be that it's only the later version of the controler, the one with the 2791, which can theoretically do double density and therefore twice the datarate....the one using the 1771 can only do single density so may have been ok, and not needed the double speed poke.Alastair wrote:What a brilliant idea when it was well known that some Dragon 32s couldn't cope with the double speed poke. My Dragon falls into that category and if I had obtained a DeltaDOS controller I would not have been best pleased with the result...prime wrote: The reason for the double speed poke, is that the Delta controler uses a WD2795 (I think) which has an inverted databus, this means that before *EVERY* bytes is written and after *EVERY* byte is read it must be inverted, this extra processing means that the 6809 cannot keep up with the WD controler unless it's running in double speed mode. A way round this of course would be to invert the whole data block before writing and after reading, so that you where not doing it as you where reading.
Yeah, was looking for a way of laying it out beter, something I'm not too good atrobcfg wrote:Most probably my friend will lend me his DeltaDOS controller so I can test it this weekend, so you can count with the ROM dump sooner or later.
By the way, I've redone the DeltaDOS and DragonDOS pages including the IC parts lists and the datasheets for all IC's. Hope you like it!
So yeah that's good.Yeah, was looking for a way of laying it out beter, something I'm not too good atrobcfg wrote:Most probably my friend will lend me his DeltaDOS controller so I can test it this weekend, so you can count with the ROM dump sooner or later.
By the way, I've redone the DeltaDOS and DragonDOS pages including the IC parts lists and the datasheets for all IC's. Hope you like it!
So yeah that's good.
Humm that might help, if I could just get a disk to at least formatrobcfg wrote:Hello everyone!
I dumped the Delta DOS rom and it's identical to the one we have here in the Dragon Archive.
Sadly, my friend is in the same situation, he has the list of commands but don't have the user manual.
I managed to discover that the drives are named A to D. To select the second drive you must type "SELECT B". I'll continue testing the controller to see if I get some more information.
I think there where two versions of the Cumana drive / interface. The early ones used Delta, and the later ones used hardware compatible with the official DragonDos, so compatible that the later Cumana rom works without problems on a DragonDos controler, and I asume that Dragon / Superdos would also work on the later Cumana controler.By the way, the Cumana drives are supposed to have Delta DOS under other name, does anybody have a cumana instruction manual? Maybe that would help a lot.
You don't need a modified drive, a standard PC 1.44MB drive will work, but you *MUST* use only 720K media. Normally though a PC drive will only work as drive 2 on a Dragon, to make it work as drive 1 you need a cable that swaps pins 10 and 12, this can be done with a twist. Please note this is NOT the same twist as a PC cable.And a last question. Have you tried a 3.5" unit with DragonDOS? I managed to get a modified 3.5" drive (it's the same mod as with 3.5" Amstrad CPC drives) working with my dragondos controller and I can format the disks up to 720kb (711kb free).
