/// The Emulation Examiner
    ----------------------
    By Jason Compton
    (jcompton@mlinknet.uucp)


  Or:  How to Amaze, Dazzle, and Taunt Users of Other Personal Computers



Before I begin, I have a few comments to make...

I'd first of all like to thank Robert Glover, editor of this magazine, for
printing the article that I just threw at him without any warning.  He's
given me a chance to broadcast the knowledge and experience and opinions
I've gathered with emulators to the general public, and I get to see my
name in print, too.  Thanks again.

Secondly, I just want to remind everyone that I would REALLY appreciate
any netmail on either emulators or my articles...it would be tough to write
this column without some sort of feedback...once again, my address is
jcompton@mlinknet.uucp.

Finally, I'd specifically like to know if anyone can guide me to either
either an Apple II+ emulator (I once had the C code to it, but it didn't
compile very well...) or an Atari ST emulator that works.  Thanks in
advance.

Now, on with the emulating...in this issue, I'd like to tackle one of the
two most practical and functional routes to emulation: PC Bridgeboards. 
AmigaWorld just ran an article listing and rating all (I presume) of the 
hardware IBM emulators.  I'll do my best not to repeat their work. Instead,
I'd like to take a look at the overall implications of committing to a PC 
Bridgeboard, and what you get out of the sucker in return.

My background on the subject?  I have an A2000 with a Commodore 2286 
8 MHz Bridgeboard and dedicated (no choice in the matter) 5.25 HD floppy 
(and you thought those 5.25 bays didn't get used anymore!), with a 20 meg 
C: partition on my otherwise AmigaDos Maxtor hard drive.  I also do my 
best to learn everything I can about hardware emulators.

In this issue, I'd like to look specifically at the 2/3/4000 bridgeboard
line, since I have experience with them.  I may as well start with my 2286,
which should pretty much cover anything you might want to know about the
2088 (the XT emulator still available through some mail-order outlets
through various promotional packages).  Both use Commodore's Janus program
to do the communicating between IBM and Amiga.  What you get with these 
packages is a hybrid XT/AT keyboard emulation (the BIOS apparently 
thinks it is XT, since the system information program Snooper returns an 
84 key configuration, but that's not QUITE true.), mouse emulation, a 
two-floppy IDE controller, Commodore BIOS, parallel port emulation, and 
CGA and monochrome displays emulated through the Janus software.  This
graphic display is relatively choppy...at a priority of +5 on an 020/14, 
the screen display isn't smooth: usable, but not smooth.  Both offer access
to the IBM slots in your Amiga, although the XT can of course only access 
XT (8 bit) cards.  Both accept coprocessors onboard.  Both are also 
discontinued by Commodore, so prices may vary wildly, depending on how 
much dealers and mail-order houses want to ditch them (I've seen the 
2088 with a 360k drive for $50 in one ad).  These boards are good enough 
if you want to run rather old software, like public domain and commercial 
software from when EGA was an expensive prospect.  And although Commodore
actually encloses detailed instructions for using Windows on a stock 2088
or 2286, I wouldn't touch the idea with a 10-foot pole.  It would be
horrifyingly slow, not to mention silly (why bother with a 320x200, 2 color,
insanely slow Windows when you can just left-Amiga-M back to Workbench?)
These two boards are the most limited of the line: any floppy drives they
use must be directly hooked up and dedicated to the BridgeBoard, so using
DF0: is out.  They also come equipped with only 512k or 1 meg (the
difference between the XT and 286).  However, a relatively simple solution
comes from Alexander Hagen (alexhagn@neabbs.UUCP according to the doc-
umentation), who has written a shareware program to allow Janus-driven
bridgeboards to use Amiga memory as EMS, thereby freeing you from buying a
memory expansion card for your bridgeboard.  His shareware pitch: You only
get 384k of EMS until you register for $30, at which point you can use up
to 32 megs, if you can spare it (both the money and the memory).

This is all well and good, but if you want to go for a system that will
bring you at least near par for the IBM world, you'll want to go at LEAST
to a 386. 

There are two options for this, but that number will soon be down to one.  
Commodore's 2386sx board is one route, which gets you the tried and true 
Janus interface, as well as newfound access to DF0:, very handy if you 
have a high-density floppy there.  The 2386 runs at either 20 or 25 mhz 
(conflicting reports here: AmigaWorld lists it at 20 while I've seen it 
advertised at 25), and again has room for a coprocessor.  Aside from 
gaining speed and DF0:, you don't get any improvement over the 2286, 
although you CAN add RAM to the board itself: but it is a highly specialized
type (This is where AmigaEMS, the program I spoke of above, comes in 
handy again).  But Commodore has apparently dropped out of the BridgeBoard
market they created, and I'm told by my local Amiga dealer that it, too, has
been discontinued, although I continue to see it carriedat low ($200)
prices.  The alternate route is Vortex's Golden Gate 386, which is where my
range of personal knowledge runs out.  Instead, I draw upon the wisdom of
Dave Johnson's article on IBM emulators and sum up what I draw from it.
Vortex gives you the parallel emulation Commodore provides, and goes a step
further, giving you control of the serial port as well, should you so
desire it (rather nice if you'd like to use your modem, I'd think. Or a
serial mouse, but there really isn't a reason for that, since you still get 
mouse emulation).  They also include monochrone EGA and VGA emulation
directly in the software, but undoubtedly at no great speed unless you've
got an 030 or better.  In addition to the nice serial port, Vortex added in
one more goodie:  SIMM support.  Even though that plant in Japan blew up
recently, SIMMs are at least easier to get a hold of than Commodore's
bridgeboard memory, so when prices drop again, it's a much more viable
memory-adding option.  This is good, because Mr. Hagen's AmigaEMS program
won't work with the Golden Gate interface.  That may not be TOO big of a
problem, however, since according to Mr. Johnson, memory can be shared
between the Vortex board and the Amiga: the Amiga can either take up to 4
megs of the board's memory, or the board can claim half of the Amiga's
memory for its use.  Vortex's press release about these boards claims the
memory can be used as both EMS and XMS, probably with the use of DOS memory
managers.

Finally, the top of the line boards: EMC's 486 bridgeboard(basically a 
Commodore 2386sx board with a 486SLC/33 installed, which in turn is 
basically an enhanced 386 with the 486sx commands) and Vortex's 486 
board, also a 486SLC, this time 25mhz.  These boards basically follow the 
patterns of their 386 cousins to the letter, although each comes standard 
with more memory than the earlier models (3 megs for the EMC as 
opposed to 1 meg for the 2386, and 2 megs for the Vortex 486 as opposed 
to 512k for the Vortex 386.) The price wall really hits home on these 
systems-I have no current pricing information on the Vortex boards, but 
EMC lists their stock board at $930 in their own ad.  To go up to 8 megs 
through them takes it to $1135.  To get an 8 meg RAM/170 meg HD 
system, with a VGA switch box (so that you can share a VGA monitor with 
a flicker-corrected Amiga), and a super-crowded 16 bit card (IDE 
floppy/hard drive controller, paralle/serial/game ports and 1 meg SVGA 
display)  is $1520.  A VESA local bus 486/33 with all of that, PLUS a SVGA 
monitor is comparable to that price.  So if you've got the monitor, don't 
mind sharing it, and don't mind the 486SLC (I believe you need to go out 
and get your own coprocessor for that line), it's cost-comparable.  
Unfortunately, you also don't get any floppy drives with it, so unless
you've got a high-density drive somewhere, you're sunk again. I highly
doubt Vortex's packages would come out any cheaper than that.

Maybe that's the point of the article, (which if you've been reading I'm
sure you're dying to hear).  Emulating an IBM is going to cost you more than
going out and buying a clone. There's not much of a way of getting around 
that.  However, if you need to conserve desk space, already have some 
IBM equipment (most notably a display card, VGA monitor,  and spare IDE 
hard drive), and/or think that having an IBM multitask with the Amiga is
just too incredibly neat to pass up, one of these boards might be worth a
look.

Oddities:  Commodore and EMC figure that you don't really NEED a PC 
speaker, and would probably be better off without one, but the 
architecture provides a place to solder one if you really want it.  Vortex 
ships one standard.

Commodore's 2286 board is double-thick, and as such blocks the Zorro II 
slot it's next to.  I can't speak for the other boards, but be forewarned.

(Warning: The next message is a hack I haven't yet tested.  I trust the 
source enough to put it in, as he sells and works on Amigas for a living,
but neither of us are responsible if you melt your motherboard.)

The A2000 has two AT and two XT slots, and one AT slot gets taken up by 
the board, leaving just one 16 bit slot available for a good VGA card and 
hard drive control, right? Wrong.  Commodore was just too cheap to finish 
turning the XT slots into AT slots.  Look carefully.  All Commodore did was 
plug up the AT bus connecter holes below the XT slots.  But it's still wired 
on the AT bus.  Just get some 36-position connecters, desolder the board 
in that location, and solder in the connecters. Voila-4 AT slots, 3 available
so you don't have to buy a multi-IO card, which are more expensive than 
buying their components piecemeal. You'll even probably have space for a 
16 bit sound card, if you like.

Commodore and the EMC 486 give you a standard two-floppy IDE controller,
leaving you on your own to get a hard drive controller.  Vortex gives you a
standard IDE hard drive controller, but leaves you on your own to get a
floppy controller...

That about wraps it up for this week, I believe.  Before I go, a few last 
words:  I apologize for the way I introduced the column last week. The 
opening sentence was about 4 lines long and was REALLY lousy English.  
I think I was just excited. :)

PLEASE give me your thoughts and comments.  My net address is 
jcompton@mlinknet.uucp, in case you missed it the two times above.

Lastly, I should point out that retroactive to the last article, many of the
products and companies mentioned above are trademarks of their respective
corporations.  Any lack of acknowledgement in the course of the article is
not intended as a challenge to these trademarks.  The author recognizes the
trademarks held by these companies.

As a final note, thanks to Katie Nelson for listening to me ramble 
incessantly about emulators and for helping me compare them to real-life 
systems.