TPDD: Difference between revisions
No edit summary |
|||
| Line 61: | Line 61: | ||
For the computer end, any rs232 reference shows the pinout, if you only look at the signal names and pin numbers, but ignore the physical location in most diagrams. Most diagrams will show the arrangement when the computer has a male plug, while the M100 has a female. But the pin numbers are correct, and you can read the pin numbers right on the db25 connector and ignore any drawings to find where pin #N actually is on the plug.) | For the computer end, any rs232 reference shows the pinout, if you only look at the signal names and pin numbers, but ignore the physical location in most diagrams. Most diagrams will show the arrangement when the computer has a male plug, while the M100 has a female. But the pin numbers are correct, and you can read the pin numbers right on the db25 connector and ignore any drawings to find where pin #N actually is on the plug.) | ||
Rick Shear has taken a new and very careful look at a real cable and the Marty Goodman doc, and has probably identified the components that Marty Goodman didn't. This is probably the most electrically accurate cable. | Rick Shear has taken a new and very careful look at a real cable and the Marty Goodman doc, and has probably identified the components that Marty Goodman didn't. This is probably the most electrically accurate cable. | ||
Revision as of 04:45, 7 June 2019
Overview
There were two versions of the Tandy Portable Disk Drive. Both were very similar. The drive is a a re-branded Brother FB-100.
Common features of both versions
- Size, shape, weight
- Batteris: 4 x AA
- Wall power: 5.5mm x 2.1mm, 6vdc, center negative, 400ma (Tandy 26-3804)
- Media: 3.5" DD, aka "720K" diskettes (not HD 1.44M)
- Drive is single-sided. The disks may be single or double-sided, but the drive only uses one side.
Tandy Portable Disk Drive
100K
Tandy Portable Disk Drive 2
200K in the form of 2 100K banks (still only uses one side of the disk)
Parts
Belt
Standard size code: FRW-8.5
Search "FRW 8.5 belt" on Google or ebay
Cable
M100SIG/Lib-09-PERIFERALS/TPDD.DO
Pinouts
+------------------------------------------------+ | | | | | RS-232C | | ___ | | +--+ +--+ +-----+ | | | 7 5 3 1 | | (o) | | | | 8 6 4 2 | | | | | +---------+ +-----+ | +------------------------------------------------+
- 1 GND
- 2 CTS
- 3 DTR
- 4 RTS
- 5 DSR
- 6 TXD
- 7 RXD
- 8 NC
For the TPDD end of the cabel, the pin numbers used by Marty Goodman conforms to the numbering on a standard IDC connector, female, 2x4, with polarity bump. (That kind of connector doesn't actually fit in the TPDD/TPDD-2, but the pinout is the same). Looking at the back of the TPDD: top-right pin is 1, bottom-right is 2, top-left is 7, bottom-left is 8. Note that most generic "Dupont" connetcor housings put the pin-1 marker in a different corner than IDC plugs do (on what we're calling pin 7). So, if you use a regular non-polarized "Dupont" connector housing, You'll have to ignore it's pin-1 marker. That's the great thing about standards, you have so many of them to choose from. ;)
For the computer end, any rs232 reference shows the pinout, if you only look at the signal names and pin numbers, but ignore the physical location in most diagrams. Most diagrams will show the arrangement when the computer has a male plug, while the M100 has a female. But the pin numbers are correct, and you can read the pin numbers right on the db25 connector and ignore any drawings to find where pin #N actually is on the plug.)
Rick Shear has taken a new and very careful look at a real cable and the Marty Goodman doc, and has probably identified the components that Marty Goodman didn't. This is probably the most electrically accurate cable.
https://rsmicro.wordpress.com/2018/08/26/tpdd-cable/
https://rsmicro.wordpress.com/2018/09/08/built-tpdd-cable-comparison-to-oem/
https://oshpark.com/shared_projects/vntX40yC
http://www.digikey.com/short/j20td4
Pictures of my own build of this cable
- The db25 hood in the digikey order above doesn't fit in a Model 100. Remove that part from the digikey order and get this one instead:
- It is quite a pain in the neck crimping the tiny individual dupont connector pins. You will also need a pin crimper that fits AWG28 wires/pins like a good old Radio Shack 276-1595, or generic "SN-28B" sold by several different manufacurers, just pick any. They can be less than $15 on ebay
- The numbers 1 to 8 on the silk-screen on the pcb DO correspond to the numbers on the TPDD connector in the diagram above and the Marty Goodman doc. So that is how you can tell which pin on the pcb is supposed to go to which position on the dupont connector. Just match up the numbers from the pcb silkscreen with the positions in the diagram above. One of the pictures in the google photos album above also shows both connectors side by side with all wires connected and all colors and all positions visible, so you can also use that picture to just look at the colors of the wires on both sides.
Software
For PCs
TPDD used a single sided double density 3.5" disk, but used a format that is incompatible with modern pc drive controllers. Normal MS-DOS formatted disks are written with MFM encoding, while the TPDD used FM encoding. Even using special software to read non-standard formats, you can't make a normal drive & drive controller read or write FM.
To read or write a TPDD disk from a modern machine, you need a working TPDD drive and the special RS232-to-TTL serial cable that came with it, and a "TPDD Client" software to talk to the drive over the serial connection the same way the M100 does.
There are several TPDD clients for more modern machines. Most of these are themselves also now no longer modern. For example Lap-Desk and PDD are both 16-bit DOS programs that don't work on Windows.
TpddTool Python TPDD Client
For M100/102/200
The normal way to use a TPDD is to install a "dos" on an M100. Several such dos's have been made. The drive came with a utility disk and a functional dos called "floppy". Others have been made by 3rd parties that provided more features or smaller ram footprint or more flexible installation/usage. There are also various special purpose utility programs aside from dos's.
Floppy/Floppy2 teeny ts-dos powr-dos