Monday, May 31, 2021

The Computer in Monochrome - Practical Advice for Using for a Macintosh SE

The Graphical User Interface is something computer users have taken for granted for twenty-five years since Windows 95 computers became ubiquitous.  Of course, to owners of any Macintosh computer, the GUI was something they had experienced since day one.  The original Macintosh was designed to be a low-cost productivity computer.  It eventually evolved into a fully general purpose computer, but the systems were sufficiently popular even in the earliest days to enjoy a wide variety of software, including games.  I recently acquired an earlier example of the line, a Macintosh SE, and decided it was worth getting it up and running.  In that process I will be sharing some of the issues I have encountered and solutions.

Overview of the Macintosh SE

The Macintosh SE is the fourth model in the Macintosh line, following the Macintosh 128K, 512K, Plus and 512Ke (Enhanced).  However, it is by far one of the easiest Macintoshes to use from a price and usability perspective.  It comes with 800KiB floppy drives and can use standard 16-bit SCSI hard drives.  It comes with 1MiB of RAM, using 30-pin SIMMs and has a Motorola 68000 running at 7.8336MHz.  The graphics are monochrome at 512x342 pixels and the sound is output through an 8-bit 4-voice 22KHz DAC. The SE is the first Macintosh to use the Apple Desktop Bus for its keyboards and mice.  Prior Macs used a RJ-11 interface and the keyboards for those machines are rather pricey these days.  I also wonder if the 9-pin mice the oldest Macs use also command a price premium.  The SE has a better SCSI bus than its predecessor, is slightly faster than any previous Mac and introduced a pretty quiet cooling fan.  

Internally, there are two bays which can hold a floppy drive or a hard drive.  The first SE's came with two floppy drives or one floppy and one hard drive (FDHD).  The motherboard has a port called the Processor Direct Slot (PDS) which is used for CPU accelerators, two ports for the floppy drives and a 16-bit 50-pin SCSI port.  On the back of the machine there are, from left to right, two ADB ports, an DB-19 external floppy port, a DB-25 SCSI port, two mini-DIN 8 serial ports and a mono headphone jack.  The power cable is a standard 3-prong PC power cable.  Underneath the Apple logo on the front of the system is the screen brightness control.  On the right side of the machine may be a piece of plastic called the programmer's switch which lets you soft reset the machine or generate an interrupt.  If yours did not come with one, you cam print a 3-D replacement.

The Apple Desktop Bus Mouse which came with the SE has a model number G5431 and the Apple Standard Keyboard is M0116.  The ADB ports on the back do not care which device plugs into which port.  Also, the keyboard has a detachable cable and a port on each side, so you can have the keyboard cable come out on the right or the left of the keyboard.  You can also daisy-chain a mouse to the keyboard instead of plugging it into the SE directly.  While you can do a fair bit of light computing with only a mouse, the system is useless without one.  My keyboard came with the Alps SKCM Orange keys and they are a positive joy to type on compared to some keyboards I have come across of similar vintage.  The large Power On button about the number row keys or to the very right of the Function Key row does not function on the SE.

The Versatile External Floppy Port

Macintoshes of the monochrome variety can always boot off floppy disks and fortunately Macintoshes do not care whether the floppy is internal or external.  This is where I once again sing the virtues of Floppy Emu.  Floppy Emu has firmware that will allow it to function with a Macintosh via the external floppy drive port.  This firmware cannot coexist with firmware which supports Apple II disk drives, but firmware updates can freely be done to revert to Apple II functionality.  For floppy images, the Floppy Emu supports 400KiB and 800KiB images in the .dsk or .img "raw" formats.  

The floppy drives in the SE and its predecessors will work much more reliably with double density disks than high density disks.  Eventually Apple released SEs with the SuperDrive which can handle high density disks.  These floppy disks use GCR encoding but also implement zone-level recording techniques to fit more sectors on the outer tracks where the tracks have a greater circumference than those closer to the spindle hub.  

However, the external floppy port of the Macintosh is more powerful than you might expect as a newcomer to the system.  Apple released an external hard disk drive during the Mac 512K days called the HD 20 which plugged into the external floppy port.  As its name suggests, the original hard disk had a 20MiB capacity.  However, Floppy Emu can present up to a 2GiB bootable hard drive image to the system, eliminating disk swapping and allowing a large amount of storage for programs.  While the external floppy port is not as fast as a SCSI solution like SD2SCSI, it is better than being stuck with floppy-only operation by far.  

Common Hardware Issues with the Macintosh SE

The disk drives in old, neglected Macintoshes may not be working.  Mine gave machine-gun rattling noises until I disconnected them.  The problem is that dust and dirt get inside the drives (which have no dust flaps) and gum up the grease that keeps the various parts moving.  Also, one of the gears in the drive's auto-eject mechanism tends to crumble apart.  These videos I have found very helpful in fixing drives like these.  Note that White Lithium Grease is not safe for plastics, do not use it with any part that comes into contact with plastic, like the drive head on the drive rail.  Here is another source for a 3-D printable replacement drive eject gear.  Until you fix them, unplug them from the mainboard.

To get into the system, you will need a long-barreled Torx T-15 driver.  There are two screws deeply recessed underneath the system's handle.  This driver worked for me.

I was fortunate in that I had no leaky capacitors to replace, (and the electrolytics in this machine are axial, not surface mounted) but the battery was starting to look crusty, so I snipped it off.  The batteries in these machines are soldered in and use 3.6v 1/2 AA-sized lithium non-rechargeable batteries, typically from a company called Varta.  I soldered in this battery holder for making future replacement easy, the holder fits perfectly in the space provided. The Macintosh will run fine without a battery, but if you shut down the machine the date and time and the other settings (like mouse movement) will be forgotten.

The Basics of Early Macintosh Operating Systems

In the early days before the Macintosh Operating System was simply known as Mac OS, the Operating System was referred to as the System Software.  System Software from 1.0-7.5.5 can be run on B&W Macintoshes, but the SE came with System Software 4.0 and will not run fully on earlier versions of the System Software.  

The main Macintosh desktop is called the "Finder", presumably because it lets the user find programs to use.  The Finder's version will not match the System version until System Software 5.0.  Closing a window is done by clicking on the box in the top right corner of the window's title.  Expanding a window can be done by clicking on the top left box, which expands it fully, or by clicking on the bottom right box and dragging, which lets you set a custom size for the window.  The top menu bar will change depending on the active program.  Ejecting a floppy disk is done through the Finder, click on the disk icon, go to File in the top menu bar and then go down to Eject, or press Apple Key + E.  Ideally you should use the Shut Down command on the Menu Bar to turn the system off, otherwise you risk losing data.

Many people may find the default mouse movement rate to be a bit slow for their tastes.  Clicking on the Apple icon on the Finder's menu will allow you to enter the Control Panel.  There you can make the mouse move much faster than the default. 

If you wish to boot from floppy, most game floppy disk images can be booted without needing to boot  the Operating System disk (called System Tools) beforehand.  Just insert the disk as the system powers on and wait for it to load.  Macintosh Garden is the principal source of game disk images these days, and I have been able to get the classic ICOM MacVenture games running on my SE (Deja Vu, Shadowgate and Uninvited were released twice, the second time fully hard drive compatible).  Some 400KiB games can run without disk swapping if each disk is inserted into a drive, and some games can be partially installed to a hard disk to speed up loading.  Operating System floppy disk images suitable for use in Floppy Emu can be found at WinWorld.  Not all games are bootable, so if you need to load them after booting the System Tools disk, then be prepared for a fair bit of floppy swapping between the OS disk and the game disks if you only have a single drive.

You will likely eventually tire of floppy-only usage and want to use a hard drive.  Suitable images for multiple devices can be found here.  I would suggest System 6.0.8 for an SE, but the SE can use System 4.0 to 7.5.5.  Some devices and emulators can only use disk image files, other devices and emulators can only use disk volume files.  SD2SCSI only works with disk images and the Basilisk II emulator only will boot disk images (but can access disk volumes).  Floppy Emu and the Mini vMac emulator only work with disk volumes.  These volumes use the Hierarchical File System, so Windows and the most modern versions of macOS cannot read them without special software.  Floppy Emu cannot function as a floppy drive emulator and an HD20 interface at the same time, so you might want to invest the time and money to get one of the floppy drives working until you can get a SCSI solution.  

But a hard drive is useless with some software to run, and to get software onto that hard disk drive, I would suggest using an emulator like Basilisk II to mount the hard drive image or volume and copy files into it and use Mini vMac to test the software prior to trying it on the real hardware.  Using Basilisk II can be a bit complicated, the guide and the disk images found here were very helpful.  I used the Quadra 605 ROM for the emulator found here and that worked fine.

Stuffit - The Idiosyncratic Archiver

If have you spent any time in the pre-Intel Mac world, you would certainly have encountered the Macintosh's peculiar archival tool called Stuffit.  The DOS world had PKZIP and PKUNZIP, Stuffit, for better or worse, is the Macintosh tool of choice for archiving and compressing files.  Stuffit was originally a shareware program, and the "Deluxe" versions had to be paid for.  Stuffit's later versions backwards compatibility is less than perfect, so those disk images I linked to above usually have a few versions of the free Stuffit Expander on them to facilitate expanding compressed files.  If you don't succeed...  The most common extension used by Stuffit archives is .sit, but .sea, .bin and .hqx are also seen in the Macintosh world.

Stuffit has a free Windows version which can be helpful in looking at archives in Windows and extracting disk images from those archives.  However, if there are program files in that archive, you must extract them within a Macintosh System Software environment.  If you do not do this, you will lose file associations and games may not run because they are not properly linked to their program files.  I had a devil of a time getting the floppy version of The Manhole to run with HyperCard because the data files for the game have a file association with HyperCard and HyperCard will not open them if that association is lost.

Finally, I had failed at first to appreciate that the free Stuffit Expander! has somewhat crippled file compression capabilities compared to the commercial version, Stuffit Deluxe.  I could not extract this archive of Shadowgate with the version of Stuffit! Expander 5.5 that was pre-installed on my hard drive image.  No, instead I had to extract it with Stuffit Deluxe's 5.5 Expander.  Also, I had to do this with System Software 7.5.5. because Stuffit Deluxe really does not support earlier System Software versions.  This archive of Shadowgate refused to expand properly without Stuffit Deluxe 5.5.

A Note about Accelerators

When I acquired my Macintosh, I did not realize at first that it had a built-in accelerator board inside it.  The board is called the Prodigy SE and was released by SuperMac Technology.  The Prodigy SE uses the PDS to connect to the system's mainboard.  The PDS provides a 68020 running at 16MHz, a 68881 Floating Point Math Coprocessor and a 68851 Paged Memory Management Unit.  It can provide up to 16MiB of RAM compared to the base system's 4MiB.  When the system boots there will be a box shown using the Prodigy SE logo.  Most B&W software will not see a tremendous speed difference with the Prodigy installed, but there will be some instances of smoother operation.  Its Utility Disk, which unlocks the Prodigy's full features, is available here.

The accelerator board causes a few compatibility issues with games.  Dark Castle refused to load unless the board was disabled.  This can be done by holding down the Interrupt Programmer's Switch, if one is installed on the side of the Macintosh SE, on bootup or reset.  The Manhole would freeze when playing lengthy sound samples unless the board was disabled.  I found The Manhole's streaming music to become garbled very quickly without the accelerator, but that could be an issue where it has to seek samples from a gigantic hard drive.

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