The thirteenth chapter of the book “The complete book of Lisa,”
Using LisaTerminal, Lisa can emulate several types of standard computer
terminals, enabling you to take advantage of the tremendous amount of software
written for these terminals. What this does primarily is connect you to
software of the past. MacWorks, the Macintosh emulator for Lisa, provides
you with a connection to the software of the present and the future.
Just as LisaTerminal enables Lisa to pretend it is one of several computer
terminals, MacWorks enables Lisa to pretend it is a Macintosh, the junior
member of the Apple computer family with Lisa-like capabilities. The similarity
between LisaTerminal and MacWorks ends, however, at this rather
simple description. Emulating a simple terminal is one thing; it involves
responding correctly to a few dozen control codes of a particular terminal with
its very limited amounts of memory and minimal processing power. Even
emulating several such terminals really is no major accomplishment. Emulating
Macintosh, however, requires simulating all Macintosh internal programs and
hardware interfaces, and doing this fast enough so that you are unaware
that you aren’t actually using a Macintosh.
Technically speaking, MacWorks loads into Lisa’s RAM (random-access
memory – a full 1,000K on Lisa) the programs that are part of the
Macintosh’s ROM (read-only memory – memory permanently built into Macintosh).
Considering that Macintosh has 64K of ROM (compared to the 2K or 3K in
most personal computers), loading this into Lisa’s 1,000K RAM would seem to be
a trivial task. It isn’t. For a long time, the type of emulation that
MacWorks represents was thought to be impossible. A long technical
struggle was necessary to prove that it is possible. An equally long
struggle was necessary to make the emulation perform at the speed expected
of Macintosh and Lisa.
MacWorks cannot execute simultaneously with Lisa’s Office System.
Unlike LisaTerminal, in which Lisa can emulate another device inside
of a window, MacWorks takes over the Lisa hardware. To use it you
must boot Lisa from the MacWorks diskette. To do so, you perform the
|Turn off Lisa if it is running. You can turn off any Profiles you have
if you want to, because access to them will not be necessary. (Details about the
HardDisk utility, which allows you to use the Profile from MacWorks,
appear elsewhere in this chapter.)
|Insert the MacWorks diskette and turn Lisa on again.
|When you hear a click from the Lisa console, hold down the Apple key and
the “2” key on the standard part of the keyboard (not the numeric keypad).
|You will hear the MacWorks diskette whir. After about 30 seconds, the
MacWorks diskette will be ejected and a single diskette icon will appear
on the screen. This icon will have a large “X” through it. Even though
this gives every impression of being an error message (which it is, under
other circumstances), everything is fine. MacWorks is now loaded. You now
need only insert a diskette containing any Macintosh software package. Your
“Macintosh” will then complete booting correctly.
You can now use any Macintosh software. Or, more precisely, almost any
Macintosh software, for there are some differences between running MacWorks and
running an actual Macintosh.
MacWorks vs. Macintosh
There are only a few key differences between a Lisa running MacWorks
and Macintosh itself. These differences are caused by the few underlying hardware
differences between Lisa and Macintosh – differences no emulation program could
ever overcome. Those include the size of the screen, the presence of a
sound generator on Macintosh, the larger amount of memory on Lisa, the speed
differences in the two computers’ processors, and the devices that can
be interfaced to each system. With the exception of the differences in screen size,
most differences are rarely noticed.
|Figure 13-1: Using Lisa with the MacWorks emulator to run Macintosh programs gives you a “big screen” Macintosh. This shows various components of the Macintosh desktop positioned on Lisa’s screen.|
Screen size. In technical terms, Macintosh has a total of 175,104 dots
on its 9” screen (342 rows of 512 dots each) – each of which can
be made to appear either white or black. Lisa, however, has a total of
262,080 dots on its 12” screen (364 rows of 720 dots each) – again,
either white or black. In simpler terms, Lisa’s screen simply is bigger
than Macintosh’s screen.
When determining how to make Lisa emulate Macintosh, Apple designers had two basic
alternatives to resolving this difference. The first was to use only the first
512 dots on the first 342 lines of Lisa’s screen when running the
emulation. This would leave the bottom and right portions of the screen
dark. The second alternative was to use the whole Lisa screen, making it
appear to be a “big-screen” Macintosh when using MacWorks
software. Fortunately, Apple chose the second alternative. This means that you
have more room on the MacWorks screen than you do with a real Macintosh.
Most of the time, you can take full advantage of this extra space, as
Figures 13-1 and 13-2 show. This
difference is most appreciated when you have several windows open on the screen.
In some cases, however, Macintosh software won’t let you make full use
of the big screen. These cases usually involve single-window programs such
as MacWrite (Macintosh’s word processing package), MacPaint,
and MacDraw (both are graphics packages for Macintosh). These programs
simply won’t allow you to make a window bigger than the Macintosh screen.
In addition to having more usable dots, Lisa’s screen has a different
aspect ratio – that is, a different ratio of height to width – from
that of the Macintosh screen. The result is that images on MacWorks Lisa are
slightly elongated in a vertical direction. While this is noticeable, such
distortion isn’t unacceptable.
|Figure 13-2: The Macintosh Pascal Interpreter, a Macintosh program that uses several windows simultaneously. Being able to make each window bigger without having to overlap them is a distinct advantage of MacWorks.|
Sound generator. Macintosh comes with a very impressive sound generator.
Lisa has no such hardware. Macintosh software that uses this sound generator
won’t produce the correct sounds when run under MacWorks on Lisa.
Memory differences. Lisa has a little more than five times more
memory than Macintosh (1,000K on Lisa vs. 192K on Macintosh). For some tasks,
this memory difference can make a Lisa running MacWorks actually
faster than the Macintosh itself. One example is copying a disk. Since
Macintosh has only one disk drive, a disk-to-disk copy works by copying a
portion of the disk into memory; then you must take out the first disk and
put in the second. The portion of the first disk now in memory is then
written onto the second disk. You must then switch back to the first disk
and read another portion of that disk into memory, and on and on.
Copying a full disk may take more than a dozen such switches and as
long as 8 minutes. On a Lisa running MacWorks, much larger portions of the disk
can be read into memory, significantly reducing the amount of disk switching
and time to complete the copying. Another example of where Lisa’s
larger memory makes MacWorks superior to a real Macintosh is with
MacWrite. On an ordinary Macintosh, you are limited to about a
fifteen-page document. Under MacWorks, the limit is many times this amount.
Speed differences. Although the central processors used in Lisa and
Macintosh – the Motorola 68000 – are identical, Macintosh’s
processor runs faster: 8 megahertz for the Macintosh vs. 5 megahertz for
Lisa. So, you would expect the real Macintosh to run at least 1.6 times
faster than a Lisa running MacWorks (at least 1.6 times faster, because
emulations always run slower than whatever they’re emulating). All this may
be true, but I contend that what really matters is whether an ordinary
user can detect any difference between the two machines, not whether
something takes 30 milliseconds on Macintosh and 48 milliseconds on the
MacWorks Lisa. Based on informal tests I ran involving a half-dozen
novice users, the difference is not noticeable.
External devices. Lisa and Macintosh do not have the same external
interfaces, so they may not be able to connect to the same sorts of devices.
Macintosh has no parallel interface, for example, making it unable even
to connect physically to a Profile hard disk. Even those devices which,
in theory, may connect to both systems cannot work properly because of the
lack of system software that enables Lisa or Macintosh to communicate with
the external device.
A MacWorks Lisa can, however, share a Profile or the internal 10-megabyte
Winchester with the Lisa Office System. This is done by allocating portions
of the hard disk when the Office System is installed. During the
installation (with the Lisa Office System I micro diskette)
you are asked to choose between various options for partitioning the disk
between Lisa and MacWorks. When a portion of the hard disk is reserved
for MacWorks, you can use Apple’s HardDisk utility to prepare this
portion of the hard disk for Macintosh files. When this is done, Lisa and
Macintosh files can coexist on the same disk, although neither system can
read the other’s files. By copying the Macintosh system files to the
hard disk, you can then operate Macintosh applications from the hard disk
without having a Macintosh micro diskette in the disk drive. This significantly
improves the speed of all Macintosh applications.
The HardDisk utility, of course, also allows you to dedicate a Profile
or 10-megabyte Winchester to MacWorks. In this case, the Lisa Office
System material is erased and all of the hard disk is used for
Macintosh files. Currently, the HardDisk utility works correctly only for
the hard disk connected to the internal parallel port. Future enhancements
will allow you to use this facility on a disk accessed via a parallel interface card.
Similarly, Macintosh currently can connect with only one type of printer –
the Apple Imagewriter. Lisa can connect with many other printers.
The bottom line
There are only two problems I have observed with MacWorks. The first is
its less than simple installation. The second is the lack of data portability
between Lisa and Macintosh.
The first problem is so obvious it is difficult to imagine that the
same designers who produced the superb user interfaces of Lisa and Macintosh would
subject you to the loading sequence described earlier. One simple but
tremendous improvement would be for Lisa to indicate after MacWorks
has been installed that “The basic MacWorks software has
been loaded. Insert any Macintosh software disk to complete the process,”
or some similar message.
The second problem is really a Lisa-Macintosh compatibility issue. Data
files created by Macintosh (or by Lisa running MacWorks) are not
readable by Lisa. This is an undesirable situation for two products in
the same family of one company. At the very least, there should be
a utility that would convert MacWrite documents to LisaWrite
documents and MacDraw documents to LisaDraw documents, because all these are
Apple products. Obviously, the ideal would be for the formats to be almost
identical. Perhaps this would require changing too much existing software.
And, of course, it is desirable for Macintosh spreadsheets and business graphics
to be readable by Lisa.
The bottom line is that, even with the few problems mentioned here, MacWorks
is an excellent adjunct to the Lisa system. MacWorks brings the growing
amount of software available for Macintosh to the Lisa user, albeit with
a few compatibility problems. No Lisa user should be without MacWorks.