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On sunday,a friend brought a Delta Dos cartridge (and I promptly scanned it for the archive ), and told me that it only works on a Dragon 32 not a Dragon 64.

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?

robcfg wrote:On sunday,a friend brought a Delta Dos cartridge (and I promptly scanned it for the archive ), and told me that it only works on a Dragon 32 not a Dragon 64.

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?

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.

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.

As far as I remember from the Schematic that I have seen the Delta controler is a pretty standard interface so I see no reason why a Dragon Data drive would not work.

OK, I've just taken a look at the images you uploaded and the board is completely different from mine, for a start it uses the earlier WD1771 controler, though why I don't know it was out of date by 1983 ! Anyway I have uploaded some pictures of the front and back of the board in my controler for comparison.

Cheers.

Phill.

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?

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...

-- Rolf

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.

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...

Alastair wrote:

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.

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...

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.

Wonder if it would be possible for robcfg to dump the rom on his friend's Delta controler, would be interesting to compare it with a dump of mine.

Cheers.

Phill.

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!

robcfg 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!

Yeah, was looking for a way of laying it out beter, something I'm not too good at So yeah that's good.
I think I have the schematic for the version that I have, I'll upload that and link it on that page too.

Phill.

robcfg 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!

Yeah, was looking for a way of laying it out beter, something I'm not too good at So yeah that's good.
I think I have the schematic for the version that I have, I'll upload that and link it on that page too.

Your friend doesn't happen to have amanual too does he, all I have is the listing of commands from one of the issues of Dragon User, so we know what the commands are but not the parameters which is why I've had problems getting it to do anything

This is the article here : http://www.dragonwiki.com/wiki/index.ph ... Measure_Up

Phill.

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.

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.

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).

robcfg 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.

Humm that might help, if I could just get a disk to at least format

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.

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.

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).

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.

Edit: corrected drive numbers.

Cheers.

Phill.