a DIY home build project...

[tofro]

An exciting project.

The propeller won't need to do QLNET because that's fully implemented in the 8302.

"Fully implemented" is a nice expression for a single 1-bit port.

Tobias

[Dave]

"At present, not all the possibilities implied by the above are implemented."
-- Tony Firshman, 1999

[Pr0f]

I like that one...

As for the ZX8302 - I was going to make it history in the DIY design, so moving the QLNet function to the propeller makes sense as it avoids complications with speed sensitive code.

Serial data is done by the DUART, so I just need to put a 4 byte counter somewhere for the clock.

[Dave]

Since QLNET is just serial data at an odd speed, can you create a special mode/clocking for a simple UART so it can handle that functionality? That way it would have a common driver with the DUART. Code re-use is good.

[martyn_hill]

Hi Pr0f and Dave

Since QLNET is just serial data at an odd speed, can you create a special mode/clocking for a simple UART so it can handle that functionality?

A couple of subtleties of the QLNet protocol down the wire that might complicate using an UART alone:
a) The 'SCOUT' phase is effectively run at a different bit-rate to the 11.2us bit-time of actual data - around 30-50uS per 'bit' (TK2 c30uS x 16, Minerva c50uS x 10).
b) How to implement the 'contention testing' during the SCOUT phase?
c) Need to leave the wire ACTIVE between bytes (4.5 to 5 bit-times) compared to the 1 to 2 stop-bits capability of a standard UART. (The ZXNet for example sends only 2-3 bit-times between bytes and this confuses the QL).

The Propeller on the other hand could take these in its stride...

[Pr0f]

That's very good info - I am sure I came across and downloaded a protocol description for the QL net, time to go look for it...

[martyn_hill]

Hi Pr0f

A good overview of QLNet is available as an appendix to the Tk2 documentation (see Dilwyn's site under Tk2), but it leaves-out a lot of low-level detail, that I have been able to augment through investigation for the QLUB Adapter project. I've posted some of my findings elsewhere in the forum and once completed, intend to document more fully.

Meanwhile, if you have any specific questions, let me know.

[Peter]

An exciting project.

The propeller won't need to do QLNET because that's fully implemented in the 8302.

"Fully implemented" is a nice expression for a single 1-bit port.

Tobias

On the QL, two 1-bit ports, one input and one output. To do it with one tristate bidirectional port (and no transistor) is Q68 specific.

[Ruptor]

The Q68 already available, this thread and the issue 8 are all the same thing aren't they or am I missing something? What has happened with this project?

[Pr0f]

Hi - no not all the same thing.

Q68 - is already available - FPGA based hardware emulation of the QL, and is a fantastic bit of work - it has it's own case and is not intended as an ehnancement to the Black box QL in it's original case

Issue 8 - is project to produce a new motherboard for the original case, fixing many of the shortcomings and problems on the orignal QL - my understanding is it will be 100% compatible with the original

My project on this thread is designed to be software compatible with the orignal QL, and fit into the same black box. It will not implement Microdrives, or the original serial ports. the IPC will be enhanced, the memory footprint will be 4MB, QL network will be available, and a pair of SD cards, plus a silicon disk and CF interface will be present. An enhanced ROM port offering access to larger ROM area and provuding I/O signals to drive arduino shields through a simple adaptor board. It will feature 4 fully specced serial ports, and a USB interface. Enhanced video offering a subset of aurora modes with output for VGA and possible HDMI.

It is hoped to provide keyboard, mouse, serial, printer (rudimentary), joystick/pad, flash storage through the usb interface, and hopefully the interface will support hubs - the project will intially only have the HID interfaces and possibly storage working - but the hardware will be complete.

Project is still at the design stage - but I have made some progress on video / serial and IPC parts of the project.