What is this 4 Floppy Drives adapter for?

[aalea]

I want to know what is the use of this adaptor.

I already know that they are for connect 4 disc drives to a Miracle Disc Interface. (using 2 pair of drivers and 2 cables)

This weekend see 2 models, one with a sticker "Gold Card Compatible" that have 2 resistor solder in the background.

And another other one without sticker and resistor is theoretically for the trump card, but I know that the trump card already support 4 drivers without need of any active chip, simply using 4 disc in the same cable configured from DS0 to DS3.

so... what is the history of this no sticker, no resistor adapter?

[Derek_Stewart]

Hi,

This a a Disk Card from Miracle Systems, for use on a Gold Card, to allow access to 4 disk drives.

Each floppy disk port allows dual disk drives, normally setup as FLP1, FLP2 or DS0, DS1. The Disk Card maps the floppy disk drives to FLP1, FLP2, FLP3, FLP4.

The Disk Card is built into the Super Gold Card.

See QL Wiki
https://wiki.qlforum.co.uk/doku.php?id= ... k_expander

Strangely the Wiki calls it Disk Expander, I bought one from Miracle in the 1990s and Miracle called it the Disk Card.

[aalea]

The wiki indicate me more or less what I already know, the wiki indicate that the one without sticker is for the trump card.

This has not sense, because one of the IC of the trump card, one of the 74LS175 has the unique proposal of provide the signals for the 3rd and 4th Drive.

So I wondering why they have 2 diferent ways to use 4 disc drives,

[Chr$]

The wiki indicate me more or less what I already know, the wiki indicate that the one without sticker is for the trump card.

This has not sense, because one of the IC of the trump card, one of the 74LS175 has the unique proposal of provide the signals for the 3rd and 4th Drive.

So I wondering why they have 2 diferent ways to use 4 disc drives,

Perhaps an earlier Trump version card lacked that provision?

[Derek_Stewart]

HI,

I think this was to allow the Gold Card, which only supports 2 Floppy Disk Drives, to have an extras 2 Floppy Disks. If you look at the Super Gold Card, the same sort of interface is present on the Floppy Drive connectors.

The Trump Card can access 4 Floppy Disk Drives.

[BSJR]

HI,

I think this was to allow the Gold Card, which only supports 2 Floppy Disk Drives, to have an extras 2 Floppy Disks. If you look at the Super Gold Card, the same sort of interface is present on the Floppy Drive connectors.

The Trump Card can access 4 Floppy Disk Drives.

At the time some new drives could only be set as ds0 or 1 and not be set to ds2 or 3. So this interface allowed the second pair to also be set as ds0 & 1 while the TRUMP Card sees them as flp3 & 4.

BSJR

[BSJR]

...
so... what is the history of this no sticker, no resistor adapter?

Your Disk Adapter has the a "DA" mark, mine is "DA2" and has these resistors on the component side.
Your 2nd PCB seems to be updated to a DA2 standard.
There is also a "Gold Card Compatible" printed on my PCB's solder side.

BSJR

[aalea]

The wiki indicate me more or less what I already know, the wiki indicate that the one without sticker is for the trump card.

This has not sense, because one of the IC of the trump card, one of the 74LS175 has the unique proposal of provide the signals for the 3rd and 4th Drive.

So I wondering why they have 2 diferent ways to use 4 disc drives,

Perhaps an earlier Trump version card lacked that provision?

Yes, this seen to explain, this is my theory:

• The Trump Card 1 (the one with 24 ram chips) only have 1 74LS175, and probably only support 2 drives, using this adaptor can be extend to 4 drives (good thing to know will be if this was from begining, o a ROM update was need for that).

• Later with Trump Card 2 (the one with 6 ram chips) this was unnecesary, (good thing to know will be if ROM continue to provide provision for this adapter).

• With the arrival of Gold Card, they recover old stock of adapter, and first adapt it, later release a second (DA2) version of it.

[aalea]

...
so... what is the history of this no sticker, no resistor adapter?

Your Disk Adapter has the a "DA" mark, mine is "DA2" and has these resistors on the component side.
Your 2nd PCB seems to be updated to a DA2 standard.
There is also a "Gold Card Compatible" printed on my PCB's solder side.

BSJR

I also think about the new drives, but, in this case a simple pasive adapter can be used to use 2 pair of DS0-DS1 drives as DS3-DS4, it's only move 2 wires.

Regarding the DA2, i can't found anywere, I will apreciate if you can post pictured of it "for the record"

[Chr$]

Checked mine and I have one with a GC sticker like yours with mods on the rear and also a D2 as BSJR describes with the mods incorporated into the PCB design.