schematics for floppy disk interfaces

[BSJR]

Interesting: the QL Wiki only refers to three versions of the interface, with pictures of two versions - the later one shows an EPROM with a "v1.19 (1987)" label on the EPROM. https://qlwiki.qlforum.co.uk/doku.php?i ... _interface

My Q-disc PCB is labelled CST-QD3 with ROM 1.13 (c)1985, bought in '87.
The layout is - almost - as the Wiki image model '84.
The Utilities disc is V3.0 with Convert, Backup, Filed, Disced & RamDrive.
There is no mention of any version in the manual.
The question is, does a later v1.1x work in any PCB version?

BSJR

[dilwyn]

This is asking a lot - would it be possible for you to take a photo of the interface for me, showing both front and back of the PC. It would help me to align these manuals once and for all.

[XorA]

Hopefully these help, these are from my card. Which does seem to be missing the heatsink.

[Dave]

As the interface uses a WD177X floppy controller, in theory you should be able to use any of the WD177X drivers, like the Trump and Sandy driver images. The only trap is that the IC itself might be decoded to a slightly different address within the 16K space.

It would certainly be interesting to play around with drivers, and shop for the best combination of floppy and TKII features.

It's also entirely possible to put a 16K image in just as a floppy driver, then decode into the next peripheral space a complete full TKII. This does leave some free space. I seem to recall having a friend put Speedscreen and a call for it in there, so when I pressed F1/F2 I was already zoomy!

There's a lot of fun to be had.

[Derek_Stewart]

Hi,

Here are some pictures of a Q-Disk 4 dated 2986, with a ROM v1.8

Top of CST Q-Disk 4

Here is a view without the heat Sink

Top of CST Q-Disk 4 No Heat Sink

View underneath

Bottom of CST Q-Disk 4

I tried to make a copy of the ROM, but the resultant ROM image did not look like a ROM image that I have saved from other QL Interface ROMS.

It looks like some sort of hardware encryption. To avoid copying the Q-Disk ROM, maybe.

Ithought about saving the ROM image with the Interface connected to the QL, but this may only work in a non-Q-Disk 4.

[aalea]

dilwyn: It's not clear in the photos, but version from 1986 (1.19) seen to have a eprom 27C128, so 16Kb, this will match to the extra commands of the version 3 of the manual.

nikosdoykas: Yes I try it and works equal, I repeat, it's the same ROM, only change the first bytes of the Copyright.

BSJR: there are any posibility to get a .img file of the utilities disk?

XorA: Thanks for the pictures, they are very clear, probabliy I do a clone of the PCB with the exact same position and tracks, only for fun... I want to check the capabilities of do curve tracks with kicad software.

Dave: I have the same idea, i was starting to create a interface with Floppy + 512Kb + TK2 and perhaps IDE, with the idea to free the rom slot, to allow use of other interfaces like ql-sd or the ICE cartridge, dongle for macomco C compiler, etc... in fact now I using 64Kb chips for the rom, because they are cheaper than the 8Kb eprom.

[aalea]

Hi,
I tried to make a copy of the ROM, but the resultant ROM image did not look like a ROM image that I have saved from other QL Interface ROMS.
It looks like some sort of hardware encryption. To avoid copying the Q-Disk ROM, maybe.
Ithought about saving the ROM image with the Interface connected to the QL, but this may only work in a non-Q-Disk 4.

How to you try to copy the ROM? Extract it an read with a eeprom programer? sometimes hardware designer swap lines in the eproms to do a easy PCB, shall be easy to restore to a readable form.
saving the rom space to a disk should work from inside of the QL.

[XorA]

I tried to make a copy of the ROM, but the resultant ROM image did not look like a ROM image that I have saved from other QL Interface ROMS.

It looks like some sort of hardware encryption. To avoid copying the Q-Disk ROM, maybe.

Ithought about saving the ROM image with the Interface connected to the QL, but this may only work in a non-Q-Disk 4.

It cant be encryption with those chips, but it could be that the D0-D7 lines are in the wrong order, or less likely the A0-A23 lines are!

[Dave]

Don't forget that with later ROMs, the QEP III was available. It made it trivial to bit reorder the data bus pins to ease PCB layout. For this reason, a few interfaces from that time used the feature just because it existed. Look at the first four bytes and bit re-order them to get the correct ROM identifier, and that will be true for the whole ROM.

[Derek_Stewart]

Hi,

I had a look at the QEP III manual, which is a little lacking in a lot of places, but the Options Sub Menu indicate a Jumble option to jumble the data or address line.

The manual should of really describe the jumble function.