Sunday, July 30, 2017

The Obscure Tandy 1000 Models

When I have talked about the Tandy 1000s in the past, and I know it has been a while, I have focused my discussions on the Tandys that were available to purchase by members of the public at Radio Shack stores.  If you walked into a Radio Shack store in the 1980s and had $1,000 to spend, you could walk out with an IBM PC compatible computer.  The 1000 line was cheap, fully functional as PC clones and played games as well as or better than machines that cost many times their price.  But Radio Shack was not the only source from which you could obtain a 1000, and the 1000 hardware was also available to institutional buyers.  So in this blog entry I am going to pull together every scrap of information I can find on the rarest, most obscure Tandy 1000s in existence.




Tandy 1000 AX - The Friendly PC for Sale at Wal-mart

In the 1970s and 1980s, the idea of walking into a retail store and walking out with a home computer was not an ubiquitous aspect of American life.  If you wanted to buy a computer in the 1970s, you often had to order chips, parts and boards and assemble them yourself.  Computer stores cropped up in the late 1970s when computers had grown from weekend-long soldering projects into ready-to-use products out of the box.  At the forefront of this evolution was Radio Shack, which sold its own designed and manufactured computers in its stores, and it had thousands of stores and over 100 computer centers.  In these stores you could often see units set up for demonstration purposes, listen to a salesman try to persuade you why you need a computer and, if your bank balance was healthy enough, walk out with a system ready to be hooked up.

Other stores would stock home computers in the 1980s, like the Atari and Commodore 8-bit systems, but most consumers looked at these lower-cost machines as toys or video game machines, unsuitable for serious business uses.  Wal-mart had been expanding since the 1960s and was always looking for new products that could sell.  PC compatible machines gained ever more popularity during the 1980s, but the prices were rather high.  Tandy's computers were within the budgets of some of Wal-mart's shoppers, so in 1987, you could have seen the Tandy 1000 AX in Wal-mart stores.

The Tandy 1000 AX is simply the 1000 SX with a change in letter on the front case badge and the rear model identification sticker.  But that was it.  The same motherboard and the same keyboard as the SX was used and the chassis is otherwise the same.  No real effort was made at obscuring the origins of the computer, and often customers walked into the Wal-mart store to buy the cheaper AX and hound the Radio Shack employees across the mall with requests for technical support.

The PC-1000 - The Second Wal-mart Tandy 1000

Radio Shack's second and last effort for Wal-mart came with the PC-1000.  This computer used a Tandy 1000 SL motherboard.  The front of the case was beveled differently from the Radio Shack machines, but the button, port and slot placements were the same, except for the power button's shape.  The rear model identification sticker mentioned Tandy but not Radio Shack, perhaps due to the issues with the AX.  I believe that the idea was to make it more difficult to make the connection in the days before the Internet that Tandy = Radio Shack.  I doubt it worked for long.  The keyboard was the same, except that the name plate now just said PC-1000 Enhanced Keyboard.  This was probably sold in 1989-1990.

Pictures of the 1000 AX, PC-1000 and their corresponding regular 1000 models, the SX and SL, can be found here : http://www.megley.com/photos/tandy

Tandy 1000 SL/E

Like most computer manufacturers, Tandy wanted to get its computers into schools.  Commodore also targeted the educational market, but neither was nearly as successful as Apple.  At some point, it released the 1000 SL/E.  This is a standard Tandy 1000 SL/2 with a different front plate badge.  I assume the "E" meant that this machine was designed for the educational market.  It may also have been bundled with the Trackstar E Apple II emulation card, which was sold by Radio Shack and would have been attractive for schools seeking to migrate away from the aging Apple II platform.  Like the SL/2, this computer hails from 1989-1990.  Interestingly, on this model the socket for the real time chip has switched places with one of the sockets for the BIOS, perhaps to make the chip easier to install.

More information about this model, with pictures, can be found at the bottom of this thread : http://www.vcfed.org/forum/showthread.php?26761

A video about the machine is viewable here : https://www.youtube.com/watch?v=HeBjifEYuZw

Tandy 1000-WS

Finally, we have what is likely the most interesting machine of the bunch, hardware wise.  This is the Tandy 1000-WS, a machine intended as a low-cost Point of Sale terminal for Radio Shack stores.  It operated the cash register, took in customer information and processed credit cards.  It could be connected to a barcode reader, a magnetic strip reader and a receipt printer.

Tandy started with the SL motherboard, but made changes to it.  First, the ports on the back and front of the unit are different.  The SLhad a 7-pin DIN for the Keyboard, two 6-pin DINs for the Joysticks, a DE-9 male for the serial port, a card edge for the parallel port and a DE-9 female for the video port.  The WS has a DE-9 male for the serial port, a DB-25 female for the parallel port, a 7-pin DIN for the Keyboard and a DE-9 female for the video display.

The SL has a chassis that supports two 5.25" drives and the SL/2 has a chassis that supports a 3.5" drive and a 5.25" drive.  The WS has a chassis like the TL series supporting two 3.5" drives and one 5.25" drive.  There is a plastic insert covering the front controls for the volume dial, reset button and the headphone and line input/microphone jacks.

In one of the expansion slots there is a card with a serial port and what appears to be some kind of network controller.  An extra serial port was needed between the magentic stripe reader, barcode scanner and the receipt printer.  The network hardware would communicate with a server in the back room, which did the real processing.

The motherboard is missing many components found in the SL.  Gone are the floppy controller, cable connector and support circuitry, three of the ISA connectors, the coprocessor socket and the audio and joystick daughterboards.  There is only 128KB of RAM in the system and sockets for only 128KB more.  The system has been confirmed to recognize 256KB of RAM with the existing sockets populated.  There is a socket for an EEPROM to store the system settings, but no EEPROM came with the system.  There are silkscreened holes for the remaining RAM to bring the system up to the 640KB max of the SL.  The system ROM is only 32KB.  On a true SL or SL/2, there is 512KB of ROM in the system, which includes the BIOS, the DOS in ROM and Deskmate in ROM.  Because this system was intended as a dumb terminal, those extra features were not required.

The system was set to boot to a Tandy terminal emulator in monochrome/hercules mode.  It came with an expansion card which provided a second serial port and what appears to be a network interface.  It has a pair of ROMs on it for booting.  Installing an EEPROM will allow the system to look for a system disk and use Tandy graphics instead of booting into the terminal emulator.  There is no third ROM socket or holes to mount one.  That third socket is where you installed the Tandy Smartwatch RTC chip.  Even though the audio board may have been removed, PC Speaker and Tandy music and digital audio output should still be available through the internal speaker.

While you should be able to restore full RAM and expansion capability to the WS, restoring full floppy drive support will be more challenging.  The floppy controller is a standard NEC 765, but the missing support chip at U18 is a custom Tandy part.  It would have to be harvested from another SL or SL/2.  Finally, the ROM sockets only support 28-pin EPROMs (64K x 8 max), so you cannot upgrade to full SL & SL/2 ROM capabilities (Deskmate & DOS in ROM).

More information and photographs can be found here : http://www.vcfed.org/forum/showthread.php?58702-Tandy-1000-WS

1 comment:

Anonymous said...

do you ever plan to also talk about the tandy 3000? i ask bc i wanted to buy a tandy 3000hl but i ended up with a tandy 1000sx

did that double scan cga also play tandy 1000 games at 640 400 resolution?