9114B disc drive vs 82161A tape drive

[Garth Wilson]

Before there was eBay which made things more available but also shot prices up, I was a HP-71 with disc drive at a swap meet for $25. I can't believe I didn't grab it!!! I did however, on another occasion, get a second 71 as a backup to my first one, brand new, with case and manuals but no box, for $25, and on another occasion, a second tape drive as a backup to my first one, also for $25 IIRC. I have a 41cx with the merged HPIL/XIO module. I still use the 41 every day.

So I have no experience with the disc drive, but I have the tape drive. I have my 41cx with a double extended memory module in it, and I have an extra 160KB of RAM in the 71, and the memory has been so dependable that I went many, many years without using the tape drive. I have programs in the 41 that have been there continuously, without ever reloading, for over 25 years. I did have a problem a couple of years ago with a CMT 96KB card-reader RAM module on the 71 though, which seems to have been a configuration problem. I had to reload a lot of old files into the 71 from tape. The batteries were so bad that I couldn't use the tape drive even with the power supply, so I removed the battery pack and clipped onto the prongs underneath to connect to a regulated 5V supply, and started loading. Tape after tape, file after file, it all worked perfectly, just like it did in the late 1980's.

The fast-forward and rewind times for a tape with a lot on it may be a bit of an inconvenience; but I have various tapes for the 41 and others for the 71, each kind of like a folder, classifying files according to different areas of work. This way the tapes used especially for the 41 never got very full, so the fast-wind times were pretty short.

The availability and price of tapes will probably be a problem. It would be nice if someone would make something to put in the tape-drive housing that would let you use SD cards. Then they would be interchangeable with other computers.

Quote:I have had a 82164A HP-IL/RS-232C Interface for almost 30 years that I have never been able to figure out. It was originally purchased to transfer data files to a PC but I moved from the "41 as a data collector project" to a real dedicated field data collector for that application. The 82164A just sits there with the power light on - and nothing else happens - no matter what I do. (Well, I can get the T/R indicator to light briefly by pressing "Reset.") :-)

I have the FSI164A (from Firmware Specialists, Inc., bought from EduCalc) which is nearly 100% compatible with the HP82164A. The main differences are that the FSI, even though a little cheaper, came with two RS-232 channels standard, and could be expanded up to 8, and it could optionally be run off of batteries. Its transmit and receive buffers are about 10 times as large. Something you might be missing in setting up the '164 is the REMOTE and LOCAL (called NOTREM on HP-41) commands. Without going into REMOTE, sending a string for example is taken to mean you want to send that out over the RS-232, instead of being a command for the interface converter. So on the 41, you might do for example:

Code:

 1  MANIO
 2  1
 3  SELECT
 4  "C0;SB6;R1"
 5  OUTA
 6  NOTREM

Notes for individual lines:
Line 1: I usually used it in manual mode and specified hard addresses, because I also had the HP8169A HPIL-to-IEEE488 interface converter on the loop which is basically transparent but the IEEE-488 side does not have auto-addressing, and you have to give it actual addresses set on them by DIP switches, for example 8 for the relay box, 9 for the signal generator, and 22 for the DMM. For devices that are on the loop, you can also have the calc look for the device, for example,

Code:

  "FSI164A"
  FINDID
  STO 00     \ Keep the address for later reference, to avoid searching again.
  SELECT
  <etc.>

Line 4: The "C0" tells it there will be no protocol. The "SB6" tells it to do 300bps. I used this for a niche-market product we developed in the 80's with a tape modem that put data on one track of a stereo cassette. The other track was used for voice. The "R1" clears the receive buffer.

This is from something similar I did with the HP-71:

Code:

RESTOREIO
A=DEVADDR("RS232")
REMOTE @ OUTPUT A; "C0;SBA;R1" @ LOCAL

I used the FSI164A with the 71B-Talk software that ran on a PC to transfer data and use the PC's keyboard and monitor as and extension of the 71.