Deprecation’s what you need

By | January 8, 2017

Snapshots to screenshotsSkoolKit 5.4 has been released. And if you’d like a copy, you can get one (as usual) from the download page, the Python Package Index, the Ubuntu PPA, or the Fedora copr repo.

This is a somewhat sad moment for the 5.x series, since 5.4 will be the last instalment. However, let’s see if we can bring some cheer to the occasion by taking a tour of some of the new features in this release before 6.0 comes along and stomps on the faces of all the deprecated ones (about which more later).

First up is sna2img.py – the sixth new command this series. As its name suggests, it extracts data from the display file and attribute file of a snapshot (or a SCR file) and converts it into an image of the PNG or GIF variety. Which could be useful if you want some screenshots for your disassembly, but the required graphic data won’t fit in your skool file, so the #SCR macro is not an option. sna2img.py also comes with the ability to crop, flip and rotate the screenshot, not to mention set the scale as large as you like. Once you’ve got your desired screenshot (or portion of it), you can incorporate it into your disassembly by declaring it in the [Resources] section of your ref file.

Also new is the @equ directive. No prizes for guessing that this directive produces EQU directives in the ASM output, allowing you to define labels for arbitrary values or addresses that don’t appear in the skool file. (Spoiler: the next version of the Spectrum ROM disassembly will use @equ directives to define labels for the system variables.) Now I look at it, I’m really not sure how SkoolKit has survived for so long without this particular ASM directive.

I could go on about the other new things in 5.4, but I need to leave space to discuss the features that are being culled before 6.0 arrives. So if you’re curious, pop along to the 5.4 changelog for all the details.

Now for the sad part. I won’t beat about the bush – on the chopping block are the following features: the #BUG, #FACT, #POKE, #EREFS and #REFS macros (which have been with us since SkoolKit 1.0); the [PageContent:*] ref file section; the parse_params() function, and the parse_image_params(), flip_udgs() and rotate_udgs() methods on HtmlWriter. And to top all that off, support for Python 2.7 and 3.3 will be dropped: SkoolKit 6.0 will only work with Python 3.4+.

Before you start tearing your hair out and cursing the day you decided to use SkoolKit to reverse engineer a game, let me say that even though they are deprecated, you can keep all your #BUG, #FACT, #POKE, #EREFS and #REFS macros and [PageContent:*] sections in place, because they can easily be reactivated in SkoolKit 6.0 by judicious use of the @replace directive (in the case of the skool macros) and the #INCLUDE macro (in the case of the [PageContent:*] section). And although the aforementioned API functions and methods will be gone, there will be near or exact equivalents available.

So that’s it for the current release and the road ahead. While you wait for SkoolKit 6.0, why not take 5.4 for a spin and create some screenshots of your favourite games with sna2img.py?

ROM here to eternity

By | October 23, 2016

ORG 0It’s not every day that a new disassembly is added to the gallery here at skoolkit.ca, but today is just such a day. The new addition to the family is the Spectrum ROM disassembly, which showcases SkoolKit’s ability to produce disassemblies of not only games, but also, well, ROMs. Or, at least, this particular ROM.

This disassembly of the 48K Spectrum ROM began life as a control file back in SkoolKit 3.6 (version 20131102), and was recently ‘completed’ and published on GitHub (version 20160709). Since then, the control file has been shed in favour of a skool file, marking the disassembly’s eligibility for publication here in both browsable and downloadable forms (in decimal format, to boot).

There’s not much more to say – the Spectrum ROM’s source code speaks for itself, I think – except that since the inaugural ‘complete’ version (20160709), the system variables have been added, with complete lists of the routines that use them. Happy browsing!

Mostly about snapshots

By | September 5, 2016

#INCLUDE(foo)SkoolKit 5.3 has been released. In the interests of compatibility with earlier versions, copies of 5.3 are available from the download page, the Python Package Index, and the Ubuntu PPA. And for the first time, RPM packages for SkoolKit are also available from Fedora copr.

So, what new stuff could there be in 5.3 (as another, less well known poet once asked)? First, there are two new commands: snapinfo.py and snapmod.py. The former command will analyse a SNA, SZX or Z80 snapshot – display register values, list any BASIC program present, show the contents of a range of addresses, and search for specific text or byte sequences. The latter command will modify a 48K Z80 snapshot – change register values or hardware state attributes, and POKE or move the contents of a range of addresses. I’ve used prototypes of these commands through the years during my reverse engineering efforts, and I thought it was time they were promoted into the official SkoolKit distribution. Perhaps you, too, will find some use for them.

On the skool macro front, the new #INCLUDE macro joins the family as the 32nd member – an interesting milestone for any power-of-2 buffs out there. #INCLUDE expands to the contents of a ref file section (in HTML mode only), and so enables you to include one ref file section in another. Funnily enough, SkoolKit 1.x provided this feature via the :: ref file macro, but support for this (and all ref file macros) was removed in 2.0. Now that the capability has been restored in 5.3, I shall expect everyone to make use of it.

There are also two new features in the HTML output department. First, skool2html.py can now write a disassembly – the code and data part, that is – to a single HTML page. This makes routines, data blocks, labels, instructions and addresses more easily searchable (using the browser’s own search function). To make the switch from many pages to one, set the new AsmSinglePageTemplate parameter in the [Game] section equal to AsmAllInOne and away you go. Second, it’s now possible to create a custom ‘box’ page – like the Bugs and Pokes pages – by setting the SectionPrefix parameter in the [Page:*] section and then defining a bunch of suitably named ref file sections, one for each box on the page. For example, if you have SectionPrefix=Foo, and then two sections named [Foo:id1:Item 1] and [Foo:id2:Item 2], skool2html.py will render a page with two boxes labelled ‘Item 1’ and ‘Item 2’.

And that’s it for the main new features. As always, details of the less interesting changes can be found in the changelog. After doing due diligence there, why not analyse a snapshot or two, and then write the disassembly you’re currently working on to a single HTML page? There can surely be no better way to spend the rest of the day.