Sunday, 1 December 2013

JetPac, +3, DIVide - At Last

My +3, with DIVide running JetPac
If you watched the last episode of the show (23) you would have seen my review of the DIVide, a brilliant device that provides huge, fast access storage for your Spectrum. It does, however, have some issues.

The main one for me was that my favourite game, JetPac, failed to work when used with a +3 and the DIVide.

Having spent hours searching the internet, and with the help of some Spectrum fans, I accidentally stumbled on the answer. As usual, it was in front of my face (so to speak!).

I toyed with re-flashing the device to EsxDos, that not only gave the option to load SNA files in 48K mode (which would fix the problem) but also allow write access to the storage.

I tested the DIVide on my 48K plus machine to make sure it was in full working order - it was. I tested different versions of the game, and even loaded from the original tape - again it worked, but only in 48K mode.

I knew the problem was this mode. Fatware dumped the user into USR 0 mode meaning the full 128k of RAM was available. Great for compatibility but bad for a selection of games that triggered the paging mode by accident. These games included some Ultimate Play The Game titles, including JetPac.

As I was running out of options I found the answer in the most obvious place, the Sinclair FAQ. (Link no longer active!). Right at the bottom it mentions the issues with 128k/48k compatibility, and to my delight, the answer.

Entering OUT 32765,48 prior to loading the .TAP file from the DIVide, forces the Spectrum into 'true' 48K mode. This then allows the game to load and play.

Now I have to go through all the problem titles and add this fix to the .TAP files so I don't have to enter it manually each time. But first, I'm going to a few games of JetPac.

Since this article I have found references to this method on the following sites:
The Spectrum +3 Manual on WOS
Product details on Lotharek.


Unknown said...

good find.

Unknown said...

Nice one! Jack the nipper now working on +2A ;-)

rogerjowett said...

Not Found

The requested URL /sinclairfaq/index.php5 was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Apache/2.2.31 (Unix) mod_ssl/2.2.31 OpenSSL/1.0.1e-fips mod_bwlimited/1.4 PHP/5.4.45 Server at Port 80

Paul (Random Kak) said...

Seem the site is no longer alive. I will remove the link. Thanks for letting me know.

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