Search found 333 matches

by janbredenbeek
Thu Nov 07, 2019 11:28 pm
Forum: The Off-Topic Section
Topic: QL vs BBC vs Amstrad 464
Replies: 4
Views: 533

Re: QL vs BBC vs Amstrad 464

My first guess: Maybe integer calculations, not using integer variables on the QL, but on the Amstrad. Their rating looked arbitrary, e.g. for graphics they assigned just one point difference, although the QL was much faster. Remember that using integer variables on the original QL had no speed adv...
by janbredenbeek
Thu Jul 25, 2019 10:29 pm
Forum: Software & Programming
Topic: Today I wrote ...
Replies: 5
Views: 524

Re: Today I wrote ...

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...
by janbredenbeek
Fri Jul 19, 2019 11:15 pm
Forum: Software & Programming
Topic: A programming question
Replies: 6
Views: 830

Re: A programming question

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....
by janbredenbeek
Fri Jul 19, 2019 10:02 pm
Forum: Software & Programming
Topic: A programming question
Replies: 6
Views: 830

Re: A programming question

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...
by janbredenbeek
Mon Jul 15, 2019 4:03 pm
Forum: Hardware
Topic: Switch off Pointer Toolkit
Replies: 11
Views: 1906

Re: Switch off Pointer Toolkit

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...
by janbredenbeek
Fri Jul 12, 2019 2:44 pm
Forum: Software & Programming
Topic: SCREEN1 = SYSVAR @ JSROM
Replies: 83
Views: 8551

Re: SCREEN1 = SYSVAR @ JSROM

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...
by janbredenbeek
Thu Jul 11, 2019 9:37 am
Forum: Software & Programming
Topic: SCREEN1 = SYSVAR @ JSROM
Replies: 83
Views: 8551

Re: SCREEN1 = SYSVAR @ JSROM

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)....
by janbredenbeek
Wed Jul 10, 2019 9:31 pm
Forum: Software & Programming
Topic: SCREEN1 = SYSVAR @ JSROM
Replies: 83
Views: 8551

Re: SCREEN1 = SYSVAR @ JSROM

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...
by janbredenbeek
Wed Jul 10, 2019 4:11 pm
Forum: Software & Programming
Topic: SCREEN1 = SYSVAR @ JSROM
Replies: 83
Views: 8551

Re: SCREEN1 = SYSVAR @ JSROM

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...
by janbredenbeek
Tue Jun 25, 2019 1:41 pm
Forum: Compatibles Corner
Topic: Q68 serial buffers
Replies: 13
Views: 1654

Re: Q68 serial buffers

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...