The Sinclair QL Forum

You are welcome

Hi!

Just... cause I always want to keep intact all QLs... Why not to use an adapter where you solder the resistor and the Switch?
Do you know what I mean?

QL_ROM_PORT == ADAPTER == QIMSI
It should not be difficult at all with breadboard or similar.
If you prefer something more refined, I could do ...

Very interesting T0nyt,
this post will help me a lot with some tests that I am doing.
I had no idea that QL could use I²C nativaly. What saves a lot of time.

Thank you

I've done a bit more work on my Literal Magic game, adding graphics. Before anyone gets too excited, they were done by me in a very simplistic style. But I do think it adds something. If you remove or rename the pics folder, they will disappear, so fear not! The point is to show it can be done ...

Hi!
Nice adaptation :)

There are smaller one that could fit better to introduce and extract from the QL.
IF you are sure about this mod, and already are the scheme of that board
Do you want to redesign the PCB to fit all inside with better localization and the switch also soldered in the board ...

Thanks tofro :)


Peripherals don't "call an IRQ" - They simply set the IPL lines. All 68k CPUs start with an IPL of 7 in supervisor mode, thus everything but the NMI (which can only be triggered by the IPC in a standard QL and would lead to a crash anyways) is ignored during initialization.

Then ...

So great to collect all that information about how works the signaling and devices allocation :)

How signals works (and their bounds) is pretty important in order to design future devs, for port expansions or even inside.

Moreover it is very helpful for mods and deep changes in the QL board.
With ...

Thanks!

DSMCL is an input to the ZX8301.

That is what I thought.


The transistor would be on the external peripheral. The transistor you see on the motherboard does something else, I would ignore it for now.

OK :) I will try but I cannot promise it :) (very interesting puzzle)


The ZX8301 ...

The addresses within a standard QL are all controlled through the ZX8301 or with the ZX8301 and HAL chip (issue 6 onwards) - the DSMCL (data strobe master chip low), signal is basically a copy of the DS signal from the CPU, but via a resistor - if you tie this line high when your device needs to ...

Thanks boths!
It helps Dave... I am taking notes and spreading the glue for all the pieces of the puzzle :)


The KILLH signal is logically A18 AND A19. It indicated an external bus cycle. When KILLH is asserted it sets DSMCL continuous High (negated). This prevents the 8301 from being active on ...