Psion and ROM cartridges

[Pr0f]

I've been trawling through QL USer and World.
This is the last mention of the ROM package by Searle I could find. It would have been the QL version of Psion Exchange using a cartridge on the expansion slot (on page 5).
https://archive.org/details/qluser_mag/ ... ew=theater

There seems to be no reason I could see that the top 128k rom space ($E0000 to $FFFFF) couldn't also be used for add on peripherals as the 128k below it ($C0000 to $E0000), even though the manual states only 8 slots of 16k? Conversely, what's to stop rom software from being addressed in to the 512k area, in a similar way the Trump card gains the extra ram it does?
With that said, on boot up the technical manual says it checks for each rom at the start of each 16k slot, but goes on to say if any rom is bigger than 16k you reduce the peripheral roms down from 8. Am guessing the top 128k is only checked at the start and not divided in to a further 8 slots or checked as such - but that isn't documented.

Does the stated total of 16 devices, relate to all devices connected to the QL including SER1, CTR 1, etc? How would having 6 extra QL microdrives have affected this total?
If 1 expansion card has multiple connections to it, do you count the card or each printer, floppy, etc connected to it?

The OS ROM located at address 0 is what determines which locations are scanned for ROMs. The various versions work in different ways - the JM ROM only scans the ROM slot and then the area at 0C0000 (first slot address) and because of a bug it does not scan for further ROMS higher in the address space - Usually the plug in card will provide a fix for this issue.

The Minerva ROM goes further than any other OS ROM and scans 0x0C000 (ROM port), 0x10000 and 0x14000 (the 2 addresses that are used by the TRUMP card, and then from the top of RAM or 0xC0000 whichever is the higher address. This means that apart from those first 3 addresses scanned by Minerva, there is no OS that scans for ROMS lower than 0xC0000, other than the ROM port address. So placing ROM in the area normally reserved for RAM means it will not be found and linked in by the OS.

Regarding the "devices" - it's probably a poor choice of word. The QDOS design allows for upto 8 of any type of device referred to by the 3 or 4 letter naming convention. What's being referred to regarding the 16 is the number of 16K "slots" that could be occupied by a plug in card (hardware permitting), and the design of that card would have a ROM at the start of that 16K address space, and then some I/O on the card - usually at the end of the 16K address space. Such cards could be Floppy disk, hard disk, eprom programmer (QEP III), Analog / Digital, what ever you can think of really. These "plug in cards" could simply just be a ROM - such as a toolkit and need not have any I/O. The technical guide and the Concepts guide refer to 8 slots and 16 slots - so I think there was some confusion.

[dilwyn]

Had Sinclair produced the Xchange ROM, it would have been for their unreleased QL successor, described in some places under the name "Enigma".

As it was, Sinclair went to Amstrad and that was the end of that.

CST were the ones to produce a successor, with the Thor range.

Danish company Dansoft later permitted free distribution of Xchange and other ROM software for the Thor machines.

Eventually, someone in Denmark, Erling Jacobsen, and later Simon Goodwin in England, made the disc versions of Xchange for the standard (well, expanded memory) QL from it. This involved among other things removing code which checked for a "Thor Watermark" in the system, which meant the original only ran on a Thor computer.

This is the "introduction" Erling wrote for it on his website in the early noughties:

Xchange for QDOS, Introduction.
Copenhagen, Denmark, July 25, 1995

Dear QL user,

Thank you for getting a copy of PSION XCHANGE, the extended
version of the original four classics.

XCHANGE was programmed for the THOR based on the standard PSION QL
software. Dansoft paid a considerable amount of money to have an
improved version of the standard software but based around the
concept of the IBM XCHANGE version. The software was then
distributed on license from PSION as the standard software running
on the CST THOR PC computer. Three versions were made: an english
version, danish and a QUILL-only XCHANGE version in danish (sorry
QL-users!).

Around 1989 the production of the THOR computers were stopped due
to cash flow problems. Dansoft and THOR International stopped the
THOR business a year later. All existing services were moved to
other people. The Ritzau news system (NB: please refer to QL WORLD
anno 1987-88) is still running in various information centres like
the danish television and radio stations. Nobody had at the time
any idea of releasing the XCHANGE software to the QL users.
However, Dansoft knew that pirate copies were around running on
QL's and other compatibles! They had copies of it!

In early 1993 we contacted Hellmuth Stuven (former owner of
Dansoft) to get an idea of the status of the THOR XCHANGE program.
He informed us that he paid for the development costs and an
exclusive agreement of the sole distribution of the THOR XCHANGE
software. He agreed to release the software to the QL community.
We now realise that PSION themselves have no objection of letting
the software flow freely among QL users (the letter printed in the
June issue of QL-world).

The THOR XCHANGE contained a minor degree of software protection
against letting the program run other platforms than the THOR
computer. It was a simple check whether a 'THOR watermark' was
present or not (the THOR serial number displayed on initialisation
of the computer). If no watermark was present the program simply
displayed 'This software is only running on a THOR', and stopped
by executing an infinite loop (the program had to be killed from
another source, e.g. SuperBASIC). This software copy protection
has now been removed.

[RalfR]

Eventually, someone in Denmark, Erling Jacobsen, and later Simon Goodwin in England, made the disc versions of Xchange for the standard (well, expanded memory) QL from it. This involved among other things removing code which checked for a "Thor Watermark" in the system, which meant the original only ran on a Thor computer.

Martin Berndt (ex Ultrasoft) has made the Thor XChange suite available for the QL as "Turbo-XChange" very early after the Thor's launch in giving the program a special screen driver for faster handling and changing the inbuilt check of the Thor's watermark so, that the program just runs on a QL and gave an error if started on a Thor (the latter was more for fun).

[pjw]

Interesting couple of posts. Thanks!

Has anyone managed to fix the XChange Quill scroll bug? This is where you scroll upwards in a document and the program hangs making it pretty useless for any serious work.

The latest version of XChange that I have is labelled XChange_Na from about 2006, but the bug goes back many versions, its origins lost in the mists of time..

[RalfR]

Interesting couple of posts. Thanks!

Has anyone managed to fix the XChange Quill scroll bug? This is where you scroll upwards in a document and the program hangs making it pretty useless for any serious work.

The latest version of XChange that I have is labelled XChange_Na from about 2006, but the bug goes back many versions, its origins lost in the mists of time..

Even the latest Version from Marcel (with the larger wIndow) has this bug. I may have a look, if the old "Turbo-XChange" also has this bug (theoretically it should be like this).

[dilwyn]

Interesting couple of posts. Thanks!

Has anyone managed to fix the XChange Quill scroll bug? This is where you scroll upwards in a document and the program hangs making it pretty useless for any serious work.

The latest version of XChange that I have is labelled XChange_Na from about 2006, but the bug goes back many versions, its origins lost in the mists of time..

Yes, indeed this would make such a difference! The "scroll bug" seems to exist in all versions I've tried, to the extent I never scroll backwards through the text and use F3 - Goto - <page number> routinely to avoid the lockup from backward scrolling.

[RalfR]

I have run QPC2 v5 (640x480 Window mode x2) with Marcel's Demo WIN and the supplied XChange V3.90L. I have loaded and merged the supplied TSL_doc until I have got 50 pages.

Then scrolled with <Cursor up/down> from bottom to top, from the middle to top and vice versa, whatever is possible. No problem, no lockup.

[Derek_Stewart]

Hi

Is the source code for Xchange, or Quill?

Pity Perfection was not free...

[RalfR]

Next try, using XChange 3.90M and Marcel's larger window version XChange 3.90N. Again 50 pages, again scrolling in all directions, again all works well, no lockups. All done with a fresh QPC2 v5 and the demo WIN. No other programs running, except the buttons.

But I remember, that the 3.90N version locked up under SMSQmulator, when I first have tried it there.

No idea why it works here today.

[pjw]

Please keep testing, RalfR, but carefully. I hope you are right that there is a fixed version. I find that when I test it is hard to crash the program. It usually occurs when Im not testing - at optimal inconvenience!

Version N is the first version with the large display, which is the one I normally use. I did test some of the earlier versions today (4, J, L, M, N) including possible variants from the qpcdemo.win. They all crashed eventually in my normal environment.