jdk@ecsvax.UUCP (Jack Kite) (01/22/85)
Between semesters this X-mas, I installed for a friend a satellite
based financial quote system ( stocks, options, etc.). The software
from the vendor was written for an ibmpc xt but I received assurances
it would run on the ibmpc AT. Since hard disk AT's are currently rare
in the Raleigh area, I bought a non-enhanced AT -- equiped it with
an ibm AT serial/parallel adapter, finished populating the system board
to 512kB, added the 128kB board for 640kB ( software requirement ),
and added a second 1.2mega-byte drive (B).
Observations:
1. On page 3 of the supplement for the serial/parallel adapter
from the Technical Reference (1502494) for the AT there is a
picture of the J1 jumper that must be configured for the serial
port lineup - port1/port2. It is of course backwards which you
can verify by examining the circuit diagram on page 27. What is
particularly aggravating about this error is it just configures
the interrupts ( 3&4 ) , so when you first set up the machine
( for port 1 ) and run your favorite asynchronous communication
program everything appears to work, until you encounter packaged
software that sets up a protocol using the interrupt.
2. The software came copy protected with Prolok (tm?? of Vault Corp.?)
on the standard 360kB floppy disk. So the question is - can the
fingerprint be read on a 1.2mb disk drive? --> a non-deterministic Yes!
It turns out that the software vendor loads a large driver ( for
communication with the satellite decoder ) in background. He does
this over the objection of the Prolok system which states I am using
an unauthorized copy. The complete system loads but does not run.
After an exit to DOS (from vendor software) and another initiation
of the vendor's software, Prolok does read the fingerprint and the
program is allowed to run. The conclusion is some bit is set in
DOS that allows Prolok to read the disk as a 360kB disk. The obvious
problem is when does this bit get set. Therefore if you are in the
market for software for the AT that has the Prolok scheme on it, you
should make sure you can return it for a refund prior to purchase.
3. There has been talk on the net about Lauren's satellite project. I'd
like to comment that last night we had an ice storm here in Raleigh
that coated the satellite dish. We never lost the signal and instead
of Lauren's 300 baud setup, we are running 9600 baud! Let's all
wish the stargate project success.
Jack Kite (jdk @ecsvax) NCSU