HP 71B SHOW PORT



#3

I have two HP 71Bs and they display independant RAM differently with SHOW PORT.

The earlier metal bottomed 1984 71B will only display ports that have been declared independent with FREE PORT, thus SHOW PORT will give:

0 4096 1
0.01 4096 1
0.05 16384 2

However, the later plastic bottomed 1988 71B displays both ports that have been declared independent with FREE PORT and ports that have not. SHOW PORT on this 71B gives:

0 4096 1
0.01 4096 1
0.05 16384 2
0.02 4096 0
0.03 4096 0

As I am new to the 71B, this confused me at first but perhaps the later model 71B's had the provision to display all internal RAM ports used or not. If you MEM(0.03), the 0.03 port above, you get an error device not found message even though SHOW PORT displays it. Then again, something might be wrong with one of the 71Bs as they should diplay the same way with SHOW PORT.

Along with the above issue, the 1988 71B came with a 34K memory module inserted in slot one. It doesn't seem to work (or I have not installed it correctly - have no information on how to do this at this point) as SHOW PORT diplays:

1 0 0

When the 34K module is inserted in the 1984 71B, SHOW PORT displays nothing about it. Again, the newer 1988 71B shows ports in use or not - even with external memory modules.

Anybody ever notice this?

Rob


#4

This is a known problem with the earliest HP71s. Get the SHOWPORT lex file and install it on the old unit and the problem will be fixed.


Possibly Related Threads...
Thread Author Replies Views Last Post
  HP-41 module covers and side port cover Nate Martin 1 630 12-02-2013, 01:51 AM
Last Post: Giancarlo
  Yet another benchmark port on the wiki: Savage Pier Aiello 35 3,748 09-26-2013, 03:22 AM
Last Post: Pier Aiello
  HP 50G serial port programming Chris Smith 2 606 06-15-2013, 02:47 PM
Last Post: Chris Smith
  OT: RPN port to Casio fx-cg10/20? Matt Kernal 4 814 04-30-2013, 12:16 PM
Last Post: hugh steers
  HP-42S with Electroluminescent screen and simple I/O port Jose Poyan 8 1,148 03-27-2013, 07:11 PM
Last Post: Jose Poyan
  AME Design Port Extender for the HP41 Dane Spillers 2 559 03-14-2013, 07:58 PM
Last Post: dane spillers
  Repaired HP-97 card reader doesn't show any signs of life jbssm 6 1,053 02-17-2013, 03:15 AM
Last Post: Alberto Fenini
  HP 30b serial port pinout xset 5 742 09-01-2012, 02:24 PM
Last Post: Walter B
  [41CL] Alternative serial connector, saving a port Kerem Kapkin (Silicon Valley, CA) 24 2,374 07-06-2012, 11:51 AM
Last Post: aurelio
  41CL Serial Port Transfer John Abbott (S. Africa) 8 1,007 06-08-2012, 04:01 AM
Last Post: Frido Bohn

Forum Jump: