Game Font Forensics

Unless you're a first time reader, you might have picked up on two recurring topics around these parts: ancient PC games, and ancient bitmap fonts.  Somehow the obvious combination between the two never came up, but as it happens, the twain can meet.  I was recently motivated to tackle a few riddles which had puzzled me for a while, and which happened to involve (are you sitting down for this?) ancient games and their fonts.

Game typography can be talked to death from any number of angles, and you can find entire books on the subject (a while ago I was gifted a copy of Toshi Omagari's Arcade Game Typography, which knocks it right out of the park).  But the nice thing is how font designs can moonlight as evidence for research - they give us hints about the tools used to create the games, reveal unexpected connections between seemingly unrelated games, and generally provide valuable insight into how things were done at the time.

In many cases, what they reveal isn't all that new or interesting.  You could point to hundreds of games just using the BGI fonts that came with Borland compilers, or those included with Deluxe Paint II, Autodesk Animator and other graphics tools.  Some were happy enough with the default video BIOS fonts, and games ported to the PC from other systems (Amiga, Atari ST) occasionally took those machines' system fonts along for the ride.  Things like that can be easy enough to spot, but in some instances, tracing the connections gets a little more complicated.

Beneath Apple Manor (Special Edition) vs. Hard Hat Mack

These two games don't seem to have anything in common whatsoever; different developers, different publishers - but both were released for the IBM PC around the same time, and seem to use an identical font.  In Beneath Apple Manor, the font in question is confined to the title screen, where it spells out "THE SPECIAL EDITION BY Don Worth"; but Hard Hat Mack uses it throughout the game.

Now, I was looking at the IBM PC versions, because that's my wheelhouse; but it doesn't take rocket surgery to figure out that their true origins lie elsewhere.  As its title so subtly implies, Beneath Apple Manor was originally an Apple ][ release.  Even the later Special Edition came out for the Apple first (1982), then for the IBM PC and for Atari's 8-bit series (1983).¹

In fact, looking at the PC title screen, the picture only takes up 280 pixels horizontally, out of the 320 available in this CGA mode: that's a rather fat clue that the graphic was created on the Apple and then converted for the IBM, without so much as centering it.

As for Hard Hat Mack, the developer credits for the various releases make it clear that the Apple version came first.  I used to enjoy this game as a kid (much later, I even went through the trouble of patching it to add 16-color composite graphics on CGA),² but back in those days I was completely unaware of the original Apple game.  At some point, there emerged some pretty convincing evidence that the PC version was machine-translated(!) from 6502 to 8088 code - I'm afraid you'll have to take my word for it, since the internet is written in sand, and the details have been lost to link rot.  But that would explain why it feels a bit sluggish compared to the original, and frankly embarrassing next to well-written native 8088 code.  I can only assume that TMQ Software, Inc. couldn't be bothered to optimize the code that their automated converter spewed out.

Anyway, now that we know where to look, here are the Apple ][ title screens for both games.  Not very surprisingly, we find the exact same font cheekily staring back at us:

Evidently the source of the font must lie somewhere in Apple land, as well.  I can't say I've ever had much experience navigating the primordial soup of very early Apple II graphics programs, but I figured I'd give it a shot.

Luckily, the smoking gun was found in very first source I consulted, Apple Graphics: Tools and Techniques by Michael Callery and Roberta Schwartz (PDF link).  It probably has more than you ever wanted to know about the subject, and it's sprinkled with a bunch of very nice pixel art illustrations, but what caught my eye was this simple bar chart on page 261 (in the PDF; the actual book doesn't number it):

Well, I'll be damned if those chart labels don't look exactly like the lettering in both BAM and HHM.  "Created with The Graphics Department", was it?  I had never heard about that particular piece of software, but helpfully enough there's a section in the book discussiong it, in which we learn that it's a "business and presentation graphics utility" from Sensible Software (not the later British game company), and that among other things, it allows you to "choose lettering from twenty character fonts".

Finding a copy of The Graphics Department was easy enough, and after a bit of disk-shuffling in AppleWin, I was able to have a look at the included 'Lettering Kit'.  As it happens, the suspect typeface is the default "mono" font, and indeed we do have a match.

It's still not precisely 1:1, however: in the program, the character cells appear to be 8 pixels wide, while both games (in their Apple and IBM versions!) use the more Apple-native³ width of 7 pixels.  The "KERN" option lets you increase the character spacing in Department, but apparently you can't reduce it.  Taking a screen grab and tightening up the spacing by 1 dot, the characters fit onto a 7-pixel grid - a better match for what we see in the two games.

All that's left to do is to compare this to what's actually stored in the game data.  Manor won't help us out here, because the font is baked into the title graphic, and isn't used anywhere else to display actual text.  On the other hand, Hard Hat Mack prints its text at runtime (on the title screen as well as the in-game status display), so it has no choice but to store its charset as an actual font.

The easiest way to exhume this sort of data is to view our binary blob (file or disk image) as one large set of graphical tiles.  If no compression is used, and if you choose the same data format used by the display hardware, there's a good chance you'll ferret out some fonts, among other things.  When we do this for both versions of Hard Hat Mack, we can see what's up:

Hard Hat Mack: Apple II, disk offset 1F707h
HGR format (1bpp/low bit first)
8x8 tiles

Hard Hat Mack: IBM PC, disk offset 0C1F1h
CGA mode 4 format (2bpp/high bit first)
8x8 tiles (2-byte skip between tiles)

The Apple version's font may be missing the lower case portion, but the part left over is better than what we got from The Graphics Department - TGD's characters are cut off past the 6th dot column, so a bunch of them are visibly missing vertical slices on the right: m, w, #, %, ?, /, \, ] and the apple icon.  If the idea was preventing the characters from sticking together, you could make a case for doing that; but since the program draws its characters on 8 dot boundaries, not 7, that 7th column shouldn't have bothered anyone.

The game data has those characters fully formed, despite the fact that they're never actually used.  That means there was no reason to fix them up by hand, so the developers must've had a better version of the font to start with.  That is, there's either a bug in the version of Department that I found (2.03), or a problem between the chair and the keyboard... or the font really does come from somewhere else after all.

As for the IBM PC conversion - besides the fact that the character order is obviously reversed, we can spot a couple of other changes.  1-dot stretches show up in alternating colors rather than white: whatever tool was used to convert the Apple HGR data to IBM CGA format, it was likely trying to crudely mimic the phenomenon of NTSC color artifacting (that's very roughly what happens to isolated pixels on the Apple; compare to that Graphics Department shot).

The thing is, the subset that's actually used in-game doesn't have those errant colors.  So that was obviously a manual fix, but they went ahead and made a few others too: comma and period are shifted left, "Q" doesn't look like a "0" flipped around anymore, and the "&" has been miracu­lously cured of its crippling disfigure­ment.  Some­what regrettably, the apple icon wasn't replaced by a "Charlie"/"Tramp" hat... contrast with the IBM version of Beneath Apple Manor, where the Golden Apple (the object of your quest) turns out to be something considerably less, uh, fruity.

Flightmare vs. Ninja

Ninja is a fun sort of game if it's 1986 and you own a PC/XT clone (especially a Tandy 1000, which I did not).  Not great-looking next to the arcade/Amiga/Atari ST versions, but having so many different combat moves was a novel thing at the time... even if the novelty may wear off when you realize that spamming a single key combo mows down entire armies of baddies.  And the fact that the devs left a sprite editor in the game itself (by mistake?) gave me one of my first "modding" experiences.

Later I came across an older game, Flightmare ("The Ulti­mate Expe­dition into Horror"): a ghoul­ishly difficult shooter where you wage post-apocalyptic aerial combat against desert warriors, vandals, and "maraudering beatnicks" (!).  On top of the humor, and the original idea of having you control your plane on a top-down and a side view at the same time, the author was skilled enough to squeeze excep­tionally smooth and fast action out of a 4.77-MHz PC.  (It also tries to pull some mightily silly tricks to fool disassem­blers and debuggers, but that's another story.)

Again, the two games appear completely unrelated: Flightmare may require ninja reflexes and discipline, but it's a shareware/user-supported game released in 1984 by Peter Adams, for the IBM PC only; while Ninja was a commercial game from Steve Coleman at Sculptured Software, with the IBM PC version written by Bryan Brandenburg ("and Soft Arts", it says here).  So, where did they get the exact same font?

I say "font", but Flightmare in fact has two of them.  The 8x8 charset seen above is used for almost everything, but there's a smaller 4x8 one, which serves to keep track of lives, enemies and time on the status display.  For this purpose the numerals (and colon) are sufficient, and as far as can be seen in the game itself, this is all that's used.

But if we look at the executable's data as tiled graphics in 2bpp CGA format, we find full sets of alpha­numerics for both the large and the small fonts.  Here they look kinda jumbled and junky; we could play around with the offsets and clean things up a bit, but it's usually easier to look at what's actually in RAM while the game is doing its thing.  Running the game, dumping the data segment, and giving it the same treatment gets us tidy renditions of both sets:

Flightmare: FLIGHT.COM offset 1E22h (8x8 tiles)

8x8 font in program memory (at DS:2871)

Flightmare: FLIGHT.COM offset 26FAh (4x8 tiles)

4x8 font in program memory (at DS:3174)

Apart from the full set of (unused) uppercase letters in the smaller charset, both fonts have a second set of the letters A through F right after the numerals.  That's a neat thing to have when you want to print out hexadecimal values, since you don't have to bother fixing up ASCII codes, so maybe this was used to show debug infor­mation in develop­ment builds or something.

Ninja also has two different fonts, in FONT2.DAT and FONT2B.DAT, but that's because they're intended for different video modes - the one that looks like Flightmare is used in plain CGA (320x200 at 4 colors); the other one is used for the Tandy 1000 mode (160x200 at 16 colors).  This mode trades resolution for bit depth, so the more-detailed CGA font data would have resulted in unsightly artifacts.⁴

Ninja: FONT2.DAT (CGA)

Ninja: FONT2B.DAT (Tandy)

So yep, Ninja's CGA font is dot-for-dot identical to Flightmare's, except that the period and comma have disappeared (and the "8" has acquired a bonus pixel at its lower right corner).  The thing is, this .DAT file isn't the only place we can find it: the executable, NN.EXE, has another copy of the CGA font at offset 0346h.

And what greets us just after this redundant copy within Ninja's .EXE file?  Why, zoinks!  It's the small 4x8 font from Flightmare:

Ninja: NN.EXE offset 05EAh (4x8 tiles)

Ninja: 4x8 font cleaned up

Ninja doesn't use this smaller font in any way; it just got dragged along when its larger cousin made the jump from Flightmare.  We of the "size matters" school of thought will be appalled at the waste of space (those two surplus fonts take up over a kilobyte... for shame!) - but that aside, it all smells like something you'd get when the data was sourced from the original developer, not like an unautho­rized rip or something.

Peter Adams (author of Flightmare) isn't credited anywhere on Ninja, but MobyGames tells us that the latter's publisher, Sculptured Software, had a Peter Adams as a co-founder along with Bryan Brandenburg (he of Ninja's "IBM version by")... and this 1996 newspaper article lists a few more people.  MG simply has entries for eight different developers who go by some form of the name "Peter Adams"; some of them may very well be the same person, but the author of Flightmare isn't explicitly linked to Sculptured.

Another fact missing on MG is that Adams and Brandenburg did work together on at least one game - the Apple ][ version of Raid Over Moscow.  And just to round out the big happy family, Ninja's designer Steve Coleman shows up in the Atari port of the same game.

So it's all a bit convoluted, and those puzzle pieces had to be picked up from all over the place, but I think it checks out.  If I hadn't noticed the identical lettering, I'd never have assumed that there might be a connection between these two games.

You may remain skeptical that the two iterations of Peter Adams (from Flightmare and Sculptured Software) are neces­sarily the very same person.  After all, there were a few others in the industry.  Besides, Sculptured was supposed to be based in Salt Lake City, Utah - while Flightmare's author wants you to send your "monetary thank you card" to him in Livermore, CA.  Then again, Flightmare itself asks you at one point: "WOULD YOU RATHER BE IN UTAH"⁵... perhaps the programmer was asking himself the same thing?

Poking Around in Pharaoh's Tomb

Pharaoh's Tomb has been the title of several unrelated games over the years, but PC old­skoolers would undoubtedly be thinking of the early Apogee shareware title - and they'd be right.  This was when George Broussard made the jump from el cheapo trivia games to action plat­formers.  Not that a flip-screen CGA/PC speaker game did much to set the world on fire in 1990, but it did a decent job carrying the torch for a genre that had lost some of its commercial appeal by then; and with the 'Apogee model' you got quite a lot of game for not that much money.

Games of this type normally don't get very wordy, so most of them tend to pick a single type­face for their lettering and stick with it.  But Pharaoh's Tomb goes above and beyond the call of duty, and uses four different fonts (not including the one in the title)... sometimes all on the same screen.

With all the lavish attention given to the appearance of text, Broussard still managed to famously mis­spell his own name on the title screen, but that's neither here nor there.  What made me nose around in the game's font usage was a silly little bug that can show up if you run it on EGA/VGA - depending on your system configura­tion.  Most of the text will look just fine, but the numbers (and symbols) on the status bar will be garbled.

Pharaoh's Tomb status bar: right vs. wrong

As some of you may guess, the guilty party here is DISPLAY.SYS - the DOS driver that controls code page selection on the video hardware level, usually used along­side other drivers for localiza­tion.  On EGA or VGA, if you use it to specify a code page, it'll hook the video interrupt (10h) and try to make sure that you always see the character set you selected.  Remove it, and the problem goes away.

Since DISPLAY.SYS relies on trapping the BIOS video service, the only programs affected are those that use the BIOS text rendering rou­tines.  This is what Pharaoh's Tomb does - although as a CGA game, it has to be tricky about it: in CGA graphics modes, only the top ("high-ASCII") half of the charset can be rede­fined.  The usual work­around is to use that for your custom font, and remap your ASCII text to those higher code points before you feed it to the BIOS func­tions.⁶

The BIOS needs a pointer to the font, which resides at the vector for interrupt 1Fh.  So if we peek at the various addresses that the game puts there, we can get at the raw fonts.  Here the memory dump is treated as 1bpp data, since that's what the BIOS routines use:

Woah, hold up there, Chief... who's "Donald L. Pavia", and what does he have to do with this game?

If you look up the name, you'll probably find that Donald L. Pavia authored a few share­ware/public domain games in his time; one example is this compilation from 1986, with educational games he wrote for his kids in Turbo Pascal.  And if you try out a few of them, such as Alphabet Games from that pack, you'll actually spot one or two of these lettering styles here and there.

You might suspect that the fonts were summarily ripped from one of those games and stuffed into Pharaoh's Tomb... and with the original author's name and address still intact, that would certainly be the more hilarious prospect.  But none of Pavia's games contain the full selection of characters and styles we see in PT, and what's there is already part of a static image, so the fonts themselves must've come from somewhere else.

One of those games did have a clue in its README file - it mentioned that the title graphic was created with something called TURBO PAINT, another program by Pavia.  Turbo Paint 2.0 can be found here, and turns out to be a decent share­ware alter­native to PC Paint and the likes: a mouse-driven paint program, written in Turbo Pascal again.  The docs say that it's been tested on the PCjr, and on EGA cards, but it can only do 4-color CGA.

The text tool has some built-in fonts you can use, and whaddya know - those 8x8 character styles sure ring a bell:

Just like in Pharaoh's Tomb, these fonts are upper­case-only, and the 'Fat' and 'Thin' ones are 100% identical to what Broussard ended up using... but those two other fonts from PT are still not accounted for.  One of them does look like Turbo Paint's 'Gothic' font, but it has those hollow vertical strokes filled in; and the other one (with the small caps) there's no sign of.

Hold on though: Turbo Paint's documentation tells you that you can load your own font files, and refers you to the author's own font editor, "NewFonts­.com".  Is that program included on the disk, you may ask?  But of course it isn't - that'd be too easy.  Pavia doesn't tell us where to get it, either, so our little archeolog­ical expedi­tion isn't over just yet.  If PT's protagonist Nevada Smith ever stars in another game, he should definitely go digging through old software libraries and BBS lists.

'NewFonts' finally turned up in the PC-SIG shareware library on disk 0484.⁷  It's a fairly straight­forward editor, made for the specific use-case of creating 8x8 fonts for CGA graphics mode, to be used with the BIOS routines via the above-mentioned "high-ASCII" trick.

The disk also has some demo programs showing usage examples, a few source files to help out, and even some code to access 16-color PCjr graphics and CGA's 'lo-res' 160x100 pseudo-mode from TP (you can use your custom fonts in these modes, too!).  But we're looking for fonts - and there are no less than 19 .FNT files inc­luded.  Here are five of them:

NewFonts: some samples

Sure enough, that's pretty much exactly what we saw in the Pharaoh's Tomb RAM dump, complete with the author's contact info.  The game just moves some code points around, and adds those little icons for the status bar.  Even the fancy Greek-patterned frame is there.  Pavia specifically writes, "You may freely use the font files [...] in any of your own programs", so it's all legit.

These same fonts were later reused in a few related games: the commercial version of PT (retitled Pharaoh's Pursuit), the sequel Arctic Adventure, and also Monuments of Mars - my personal favorite of this bunch, and a game that obviously has much in common with the others, although it was written not by George Broussard but by Todd J. Replogle.  Unlike Broussa(r)d, the latter got his own name right on the title screen... but then promptly proceeded to misspell "Scenario Software" as "Scenerio".  Was this a contractual requirement with Apogee, or just something in the water?