George Hines Floppy Remapper moves to version 4a!

One of the better sellers, even before the store was open has been the George Hines Floppy Remapper. This is a great device to pop into your TRS-80 Model III, TRS-80 Model 4 or TRS-80 Model 4P. In all devices it allows you to change the addressing of your disk drives using a simple OUT command.

The main reason for remapping the floppy drives on these computers is to enable booting from drives other than the fixed internal drive 0. This is particualy useful when paired with a modern external floppy disk emulator such as the USB HxC emulator. This avoids the need to take apart the computer, swap cables or replace your internal vintage floppy drives. There are 8 combinations pre-programmed, but if there is a setup you’d like we can easily reprogram it for your specific needs.

Features

1. Should work in the TRS-80 model 3, model 4, model 4 gate-array, model 4P, and model 4P gate-array computers
2. Eight different floppy drive mappings are supported, allowing booting from any drive (0-3) with a choice of two different maps for each boot drive. This map can be as simple as swapping drives 0 and 1 (useful perhaps if they are different types).
3. Mappings are controlled via software using a simple “out” command (conveniently in Basic). You can set the current map (which will survive a computer reset), or set the default map (to be used upon computer power on).
4. An optional disable switch can be installed (if desired).
5. As a bonus for Model 4P users, this board adds support for two external floppy drives (which previously only supported two internal drives). Inspiration for this feature came from a magazine article in 80 Micro (January 1986), while significantly reducing the modifications needed.
6. Optional (limited) motor control is supported, turning on drive motors only when they are accessed. This is useful to avoid wear and tear on your internal floppy drives when primarily using external (likely virtual) drives.
7. LEDs on the board display the current map, default map, enable status, and mode. Sadly the LEDs are not visible when the computer is assembled (but they are useful for debugging, are pretty colors, and they blink).
8. When booting from a M3SE or FreHD, the remapper can be used to conveniently remap the two internal drives (as the remaining drives are allocated to Hard Disks).
9. George made every attempt to make the board “easy” to install (or remove) with the mimimum number of board changes. On most models, you only need to install one socket (while two models require a single jumper wire). Other features are optional.

SO WHY MODEL 4a

The model 4a was made because the original Floppy Remapper was only available as a Gerber zip, BOM, positions file and hex for the PIC. This was fine in the beginning to get them made, and we did this for over 30 units that we bought in drips and drabs (5,5,10,10). We’re next buying 25 of them and wanted to change the look a little.

SO, I took on the task of using Kicad to pretty much copy it as close as possible. This meant checking part alignment (I used a clear acetate to print out the original, and then would print mine out on paper, overlay the paper with the acetate, and adjust to the point I’m probably off less that .2mm), ensuring all traces, vias, components, etc were accounted for. Once I came up with my final design, I sent it to George himself to check out and got the thumbs up from him! (We’ve even kept his name on it)

WHAT’S IT LOOK LIKE?

Glad you asked

WHATS NEXT?

There isn’t any added form/function currently, but if we decide to do something, we have a base to work from. We’re waiting (impatiently I might add) for parts to show up, and we’ll be getting a batch of 25 done!

Theres still some in the store, so pick up yours today! (Or if not, let us know you’re interested when we restock. 🙂 )

As for what we’ve got in the works…. Well, lets just say it’s DOUBLE what we have now. 😉