The Sinclair QL Forum

Today I wrote a small, but perfectly formed recursive assembler routine. And it worked first time! That never happens. (I suppose I won't be able to say that again!) You''ll get to see it in the next exciting installment of the Assembly Language ePeriodical. Coming soon. (For certain values of 'soo...

Agree that generally, an address can be negative (not only on the Q68, the Q40/Q60 have nearly the same layout). Some internal routines in SMSQ/E and QDOS, however, like the queue and list support, do assume and rely on the fact that "normal", working memory addresses are always positive....

Can it safely be assumed that a RAM address can never be "negative" in a SMSQ/E system? Ie, that so much of the system relies on the assumption that RAM will never exceed 2GB, that any negative return from some function can be taken to be an error code rather than a valid address..? Askin...

One notable issue with JM ROMs is that when you load a BOOT program which loads extension commands, you cannot use these commands in the same program until you do a NEW or LRUN. One way to avoid this is to load only the extensions first (LRESPR) and then from there LRUN a second boot file which cont...

Does the very same POKE, just hidden in a BASIC extension. And less flexible. It only allows for square-shaped pixels or the standard 512x256 on a 3:2 screen. What if you have a Q68 with 1024x768 on a 16:9 monitor? (the value to POKE can be calculated by dividing (Xresolution/Yresolution) by the wi...

POKE_F !196!330,1 (and also POKE_F !$c4!$14a,1) gives ERR.BP in QPC2. That's interesting. Which version are you using? (the aspect ratio POKE is only supported from SMSQ/E 3.00 onwards, and not in QDOS/Minerva anyway). It does work in SMSQmulator too (even with no extensions from BOOT file loaded)....

SMSQ/E has a system variable in which you can set the aspect ratio so you will get perfect circles again. And how do you start this? It's a float PT_ASPRT at offset $14a in the CON linkage block pointed to by the system variable SYS_CLNK at $280c4. So you can read it out using PEEK_F(!$c4!$14a) and...

Also bear in mind that the pixels of the original QL screen are not square-shaped. The original QL screen was made for a 4:3 television screen (the actual aspect ratio was about 3:2, which caused the horizontal overscan on TVs). However, the X/Y pixel ratio in MODE 4 is 2:1 (indeed, QDOS also assume...

I tried SER_BUFF 1,80,80, SER_BUFF 80,80 and SER_BUFF 80. But I just discovered that all SER_xxxx commands give a 'not found' error. Looks like they cannot find the driver's linkage block somehow. Found the bug. All the SER_* commands set the parameters through a Thing called 'ser_par_prt'. However...

It's important to distinguish mass storage driver issues and SER. The SMSQ/E mass storage driver can get painfully slow during write, and blocks everything else. This affects ethernet as well - software buffers can't help reliably because no interrupts are handled meanwhile. Trying with Ramdisk ins...