Spectrum Emulators on the A1200

               An article by Richard Hewison

I always use my PC and the excellent Z80 v3.02 for emulating the
48k and 128k Spectrum. However, recently a number of emulators
specifically beneficial for the A1200 Amiga have appeared. My
A1200 has a hard disk and an extra 4Mb of memory. Terry Brawls
wrote in issue 37 asking for comments on these emulators so here
they are!

ZXAM version 1.6B (previously known as Spectrum AGA)

This particular Shareware emulator is designed to run best on AGA
Amigas (the A1200 or the A4000). The Fast AGA version requires
Workbench 3.0, a 68020+ processor and the AGA chipset. The OCS_ECS
version needs Workbench 2.04+, a 68020+ and any chipset.

One of the latest features to be added to this emulator is the
facility to load and save to and from tape. Loading needs a custom
interface to work properly. The interface plugs into the joystick
port and is available from the author (or you can make your own
thanks to the supplied diagram). The routine is a ROM patch which
intercepts the Spectrum's own routines when they are called upon
to load. Unfortunately, Turbo loaded games won't work and you
shouldn't touch the keyboard during loading or saving either.

ZXAM v1.6b can handle PC, Mirage, Z80 and KGB file formats
automatically.  These are various snapshot file formats that are
used by other emulators on the Amiga and PC. Mirage is effectively
the .SNA or .SP file formats. PC is from a slightly obscure IBM PC
emulator, whilst KGB is from the KGB emulator which is now quite
old hat on the Amiga.

One of the most impressive aspects of this new version of ZXAM as
far as I am concerned is the AREXX scripts which allow you to
perform a number of tasks.  By far the most useful is the ability
to convert the .TAP tape files from the PC emulator Z80. These
files are effectively emulating a tape. I have converted a number
of multi-load games on the PC as .TAP and they can all be
converted to run on ZXAM v1.6b. You end up with a collection of
small files which you are prompted to load one by one. When the
game has finished loading the particular level, it will stop
asking you to select a file and will run the game. The AREXX
facility also allows you disassemble the Spectrum's memory (if
you're into that kind of thing).

On my A1200, the games run at about the same speed as an original
Spectrum, but it is still noticable on some of them that they
aren't running at full whack. Just compare this to a minimum 386
33 Mhz PC which can run under emulation at some 220% the speed of
a Spectrum 48k or 128k. For adventures that are text only, this
doesn't really matter, but for graphic based games (adventure or
arcade) it might be a little off putting in some games.

There are lots of other features built into this emulator, far too
numerous to detail here. According to the document file that comes
with the emulator, v1.6b will be the last 48k only version of the
emulator. Registered users will get a 128k emulator in the next
version. Whether there will be any more shareware versions remains
to be seen, but if you have an A1200 this is as good as it gets.
As with most emulators these days, ZXAM legally uses the original
48k Spectrum ROMS thanks to Amstrad's decision to allow them to
become available in the Public Domain.

With any luck, Sue should have this Shareware emulator included in
the SynTax library soon. If you find the emulator useful, the
author asks you to register for $15 (U.S.) after using it for more
than a month. I haven't used it much as I prefer the PC emulator
Z80, but if I learn any more about the registered version I will
pass the information on.

UPDATE: Version 1.6b has now been superseded by version 2.0. The
emulator is still 48k, but it has multi-tasking and 128k sound
emulation for those 48k programs that can use it. The 128k version
is still in development.

@~ZXAM v2.0 is on Disk 885 ... Sue

                              - o -