The Sinclair QL Forum

Flash must be in pairs - is that always true ? What if an entire line was to be set for flash, and somebody made use of the fact that flash would be reset at the end of the scanline - then you'd only have one flash bit set at the start of a line and no corresponding toggle off. In my opinion that c...

Per, you seem to be assuming that flash bits don't mean anything in MODE4 - They do, they're just not flashing the screen, but instead are Green bits on even pixel coordinates. High byte (A0=0) Low Byte (A0=1) Mode D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0 G7 G6 G5 G4 G3 G2 G1 G0 R7 R6 R5 R4 R...

Thanks Tobias - that begins to make some sense to me. You mention the linker control file (is that a '.ctx' file I've seen someplace?), so each assembler source file is listed there. Got it. And is it the .ctx file (or whatever) that you then tell the assembler to go assemble? M. Not quite. The lin...

In fact, when you are assembling to a relocatable object file for linking, you need to use a section directive. If you simply want to link a number of relocatable (code) files together with no specific positioning, you can simply put your code in multiple _asm files and use the same section name for...

100 DEFine PROCedure doSomething(dng) 110 some calculations 120 IF done THEN EXIT doSomething 130 do some more 140 END DEFine doSomething You should utilize EXIT and place the END DEFine at the very end of the procedure. And thanks for your nice game! No you shouldn't. EXIT (at least on SBASIC) wil...

Georgeo, END DEFine is intended to mark the end of a definition. As definitions only have one beginning and one end, there shouldn't be more than one END DEFine in a FuNction or PROCedure. Premature exit from a PROCedure or FuNction should always be done using RETurn. You can easily check this by tr...

I actually think Martyn's way is the only way to successfully guess the mode. Other than the relatively un-used (thankfully) FLASH feature, there is no way to distinguish the screen storage. (And I think I have successfully removed all programs that excessively use FLASH from my systems anyhow becau...

Is the size of standard mode 8 screen dump 32768 b - same as for mode 0/4? Yep. The original QL's screen memory is 32kBytes and all (both) modes use it fully. When the Q68 manual states that it has a "Standard QL MODE 8 256x256 pixel (8 colours)" mode, would a screen dump also be 32k? Yes...

Go with Martin Head's approach or Go with your second approach and find it doesn't work, then go on as above ;) Entering a device driver by a TRAP through another device driver access layer function from a TRAP simply doesn't seem to work for me at all in QDOS. In my experience, somehow the system m...

This seems more like a problem with the 8301 ULA and surrounding chips (74LS257 and 74LS245) The 8301 is OK and I have the 74LS257 and 74LS245 replacements. May I adopt the testing tecnique of temporarily put the new chips on the old ones, or must I unsolder the old chips? I have used use that tech...