Search found 365 matches

by janbredenbeek
Sun Dec 15, 2019 12:59 am
Forum: Software & Programming
Topic: Minerva, C68 and memory mysteries
Replies: 5
Views: 897

Re: Minerva, C68 and memory mysteries

There is a huge difference between the memory management of Minerva and SMSQ/E. SMSQ/E does not serve memory allocations from the Common Heap but from the TPA, which lies above 1MB in memory. Memory below 1MB is reserved for slave blocks. This by itself does not explain why allocations by C68 fail o...
by janbredenbeek
Fri Nov 29, 2019 2:32 pm
Forum: Software & Programming
Topic: THE DISTRIBUTION - Word is out!
Replies: 36
Views: 7015

Re: THE DISTRIBUTION - Word is out!

Well over 1000 copies of THE DISTRIBUTION have been downloaded since the availability of the public download in April 2015. Maybe not the biggest Release in QL software history, but quite a figure. Because today is an important date for me, I decided to produce and release a RELOADED edition of THE...
by janbredenbeek
Thu Nov 07, 2019 11:28 pm
Forum: The Off-Topic Section
Topic: QL vs BBC vs Amstrad 464
Replies: 9
Views: 1116

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: 671

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: 1057

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: 1057

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: 2372

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: 90
Views: 12138

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: 90
Views: 12138

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: 90
Views: 12138

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...