Thursday, January 21, 2016

Tandy Color Computer Mice - A Viable Alternative for Tandy 1000s without a Serial Port?

When Tandy designed its 1000, it helped reduce R&D costs by taking certain portions of the design from other of its computers.  The 1000's keyboard is more-or-less identical to the Tandy 2000's keyboard.  The Tandy 1000's joystick interface and connector was previously used in the Tandy Color Computer.  While neither the Tandy 2000 nor the Color Computer are IBM PC-compatible computers, these interfaces were sufficiently similar to the PC keyboard and joystick interface to work with most PC software.




The first several Tandy 1000 models, the 1000, 1000A, 1000HD, 1000SX, 1000EX and 1000HX did not come with a built-in serial adapter.  PS/2 ports would come much later to the Tandys.  The 1000SX had five expansion slots, so adding a serial adapter is easy for that machine.  The 1000/A/HD can also accept a standard serial adapter, but they only have three slots and need at least one of them for memory expansion.  The final expansion board had room for a PLUS card to add as a daughterboard, and Tandy sold a serial adapter PLUS card.  This PLUS card the only way you were supposed to add a serial adapter to the Tandy 1000EX or 1000HX.  The EX and HX are the most difficult machines to upgrade because they use the odd PLUS form-factor and BERG-style connectors instead of edge connectors.

Tandy Deluxe Joystick (early model)
The Tandy TRS-80 Deluxe Joystick, Tandy Part No. 26-3012 was marketed for both the Tandy 1000 and Tandy Color Computer lines. It used a black and off-white color scheme with a red and a black button.  The black button does not work in the Color Computer 1 or 2.  It is self centering, but there are a pair of latches on the bottom that you can use to allow for free-form movement of each axis.  It has a pair of trimmer controls to assist in obtaining a proper center for the joystick.

Tandy Joystick (also come with black handles)
Tandy also marketed a pair of cheaper, one-button joysticks, Tandy Part No. 26-3008, that are non-self centering for the Color Computer, but you can still use them for the 1000 line.  Of course, considering how cheap they are, you would have to be truly desperate to put up with them.   These joysticks have a black base, silver or black handle and red button and were sold as a pair.  They do not have any type of trimmers, making them even worse for trying to center a joystick.  Nonetheless, they do technically work in a Tandy 1000.

Tandy Color Mouse - Very Apple Lisa like
Tandy also marketed a pair of mice for both computers.  The Tandy TRS-80 Color Mouse, Tandy Part No. 26-3025, had one button and used a black/red scheme, just like the cheap joystick pair.  The Deluxe Mouse, Tandy Part No. 26-3125 came later but had two buttons and used an off-white color.  Both use the joystick connector, and unlike the joysticks both mice were advertised for the 1000 line.  You could also get Touch Pad that plugged into the joystick port.

Tandy Deluxe Mouse - A bit more like Microsoft's Green-Eyed Mouse
Internally, the Tandy Mice does not use rotary optical encoders like every other ball mouse ever made. Instead the ball moves a pair of potentiometers, just like the Tandy and IBM PC joysticks!  There is no microcontroller inside to encode anything as there would be with a serial or PS/2 mouse.  The Tandy mice are read and function just like a joystick, the only difference being the way you manipulate the potentiometers.  They have no trimmers and are difficult to calibrate because it is not obvious where the mouse "ends".

 I'll spare you from the corny puns I could make about steel balls,
The Deluxe Mouse contains a steel ball and a pair of soft rollers which end in gears which turn the potentiometers.  You can move the ball to a point where the potentiometers will not go further.  Unlike Serial, PS/2 or bus mice, the joystick interface cannot generate an IRQ.  This means that the mouse cannot tell software that it has moved, instead the software must poll the joystick port at regular intervals.  Here are a few photographs of the Deluxe Mouse's internals :





Many DOS games support a mouse cursor, and a couple will work reasonably well on a 4.77MHz or 7.16MHz Tandy system.  The early LucasArts SCUMM games starting with Maniac Mansion and the MacVenture ports like Shadowgate have a cursor which can be controlled with a joystick or a mouse. Wasteland and Dragon Wars also support a cursor, but those games (ported from the Apple II) can be played best by mastering the keyboard commands.

There are a pair of joystick-to-mouse drivers in the wild.  One is JOY.SYS and is loaded in CONFIG.SYS.  This works well with the Tandy Mice.  The other is JMOUSE.COM and can be loaded with AUTOEXEC.BAT.  This works well with regular joysticks but not with the Tandy mice because it requires calibration. The Tandy Deluxe Joystick can work as an ersatz mouse using these programs, but expect some jitter in the cursor and imprecision.  You can download both from here : http://www.oldskool.org/guides/tvdog/utilities.html

Tandy also released the Digi-Mouse, a bus-style mouse that does not work in a serial or PS/2 port.  Its expansion card comes in standard pin connector and PLUS-style form factors.  Both adapters have a real time clock chip on them but are hard to find.  Obviously, both the mouse and clock chip require special drivers, which can also be found at Tvdog's site.  The driver has a Microsoft copyright as viewed in a hex editor.  The Digi-Mouse connector uses a 9-pin connector and can support three buttons and two pairs of quadrature signals, just like a Microsoft Inport mouse.  I would not be surprised if Microsoft's Inport mice could also work with the driver and expansion card, although the signals may require rewiring.  The card uses IRQ3.

Eventually Tandy would release its own serial mice and PS/2 mice.  The Tandy 1000 TX is the first Tandy 1000 to come with a built-in serial adapter, and the later 1000s always had one.  The TL/3, RL, RLX and RSX also support PS/2 mice, but you will have to manually set the IRQ in the mouse driver (except for the RSX) because these systems lack IRQs 8-15 and the PS/2 mouse IRQ is assigned to 2.  They assign the IRQ to 3.

Additionally, Personal Deskmate, which came with the Tandy 1000 EX, comes with the JOY.SYS driver. In fact, with Personal Deskmate, the cursor will be corrupted with any mouse driver except the JOY.SYS driver or the Digi-Mouse driver (see below).  Personal Deskmate 2 and later GUI versions are not picky about the mouse driver loaded.  Unfortunately, the JOY.SYS driver does not like the PCT 286 Express Accelerator Card and will refuse to allow the PCT software to run if the JOY.SYS driver is installed.

The Tandy Deluxe Mouse still shows a jittery cursor with the JOY.SYS driver and many programs.  Low resolution graphics and text modes will not show as much jitter as medium and high resolution graphics modes. Moveover, some games like the high resolution version of Maniac Mansion, do not like the driver and will show some erratic cursor movement.  If you are going to experience jitter, then you may as well use a joystick instead of a mouse.  Ultimately, if you have a joystick with the free-form switches, I cannot recommend using these mice on a Tandy 1000.

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