Overview
In 2021 we released the Backpack Drive (BPD); a small battery powered SD card drive for the TRS-80 Model 100 series of computers which emulates the Tandy Portable Disk Drive 2. The venerable TRS-80 Model 100, Tandy 102 and other members of this family line are still much loved and used today. The size, portability and wonderful keyboard make them a very nice machine to use. The drawback, as with many vintage computers, is exchanging data with a modern computer. Support was later added for the Sinclair Z88 and Epson HX-20/PX-8 (with connection adapters).
In 2022 when the original microcontroller became unavailable, we switched to a newer model with more RAM and FLASH memory. This also allowed for adding an XMODEM mode to handle file transfers on any system which could do XMODEM over a serial port. Thus, was born the Backpack Drive Plus (BPD+).
Now in 2024 we have released the Universal Backpack Drive the uBPD, which features a newer version of the same microcontroller which offers even more RAM/FLASH memory. This allows merging the multiple firmware versions (Epson + M100 et. al) into one. This makes it easy for users to use one Backpack on all supported devices by just changing the operating mode with the MODE command in CLI. Production was also streamlined, allowing us to keep the price at the same low level.
In addition to the uBPD being able to simulate various vintage disk drives it also has a powerful ‘Command Line Interface’, CLI, mode which you can use from the M100 TELCOM application (or similar). Using the CLI you can set the Time/Date for the real time clock on the Backpack, set the Backpack to work in ‘WP2’ mode for use with the Tandy WP-2 portable word processor or other machines.
When a firmware update is available for the Backpack installing the update is as simple as copying the file to your SD card and using the CLI to start the update process. No complicated programming devices or external wiring required.
Based on feedback from customers we have added a few optional extras as well. While just about any 16gb or less micro-SD card can be used you can add an 8gb card that is preloaded with the required file set. This helps get you up and running very quickly. The real time clock in the Backpack runs from a CR1025 coin cell battery which will last for many months. We are offering spare clock batteries as a convenience.
If you wish to use the Backpack with a Tandy WP-2 you will need a DB9 to DB25 adapter, available as an option. If you wish to use the Backpack with a Sinclair Z88 you will need a DB9 to DB25 adapter, available as an option. The WP-2 and Z88 adapters look the same but are wired differently. An adapter is also required, for the Epson HX-20/PX-8 computers. Both CLI and Drive mode work on the PX-8 but as no terminal program can be found for the HX-20 only the drive mode will work. Since Epson used Mini DIN connectors on these machines you will need two Mini DIN cables for the PX-8: https://www.ebay.com/itm/372702390151 . For the HX-20 you will need an 8-pin DIN to 8-pin Mini DIN cable. There is also a pinout of the connectors in the manual if you want to build your own cables.
| System |
Emulation |
| Epson HX-20 |
Drive support via Epson adapter |
| Epson PX-8 |
File support via Epson adapter |
| NEC-8201(A) |
TPDD-2 Direct connect |
| Sinclair Z88 |
TPDD-2 via Z88 adapter |
| Sharp PC-1500 |
Full support via CE-158 & CE-158X (CE-158X full integration) |
| TI HEXBUS |
HEXBUS Drive (TI-74 & CC_40) via HEXBUS serial adapter |
| Tandy WP-2 |
TPDD-2 via WP-2 adapter |
| TRS-80 Model 100/102/200 |
TPDD-2 Direct connect |
| XMODEM |
Systems that support XMODEM over serial connection |
The documentation, SD card file set, etc. can be found in the Documentation tab.
