The Sinclair QL Forum

i can not get it to work as a qdisk .

i compared it with a 1.18 and there are a lot of differences .

maybe it is a dodgy attempt ..............or it is jumbled incorrectly .

there must be members with the genuine thing , maybe they can read the eprom

i re-burned an eprom , and the result is nothing .

so i doubt if this image is usable ( or i lost my control over the eprom programmer )

would it be possible that cst changed the jumbling with the versions of the qdisk interface ( as i have read several version do excist )

anyone succesfull with version 1.19 ??

Hi,

I did start to look at this, but I have a couple of other jobs to do.

But, it is just a matter of finding the relationship of the data and address lines of the ROM in comparison to the QL Bus and reoranising the data to suit. not a simple job, but probable do-able.

I made some investigation:

The file you found in the disk is a "bad dump" of a 1.19 version of the rom.

It have the correct scramble of the address bits that use the V4 PCB.

the address 0000h is bad, it's 00h and should be 4Ah, with this change the ROM boot (in a emulator) and show the copyright information:
CST QDisc Controller V 1.19 (C) 1986

Unfortunatelly it also show the message

rom checksum failure

This is a message algo present in V1.18, and any change in the rom make show this message. (I think the ROM position 37FEh has a 16bits checksum, this is the boundary that the interface can read).

In the 1.18 after this address is all empty (FFh) but in the version 1.19 there are some bytes with other information, and not seen to have a pattern, this make me suppouss that this dump come from a corrupt ROM, so there is not much that we can do.

we can only wait for another member to read his eprom and sent it to us.