[ NNSquad ] Re: Intel charging extra to unlock full CPU capabilities

[Barry Gold <BarryDGold@ca.rr.com>]

On 9/18/2010 9:02 PM, Lauren Weinstein wrote:
> Intel charging extra to unlock full CPU capabilities
>
> http://bit.ly/almMkl  (Engadget)
>
> This is indeed not a new game.  IBM, DEC, AT&T, and other firms have
> at various times used this or similar approaches with various
> hardware.  But brought down to the level of consumer CPUs, reactions
> might be significantly problematic.

Hah!  You're right that there's nothing new here.  Back in the 1970s we 
had a project that used a 370/145 (a fairly small machine in the IBM 
System 370 series).  It's "console" was a 120 cps dot-matrix terminal 
that could, among other things, produce a hex dump of memory -- or of 
microprogram memory.

For reasons I don't remember, somebody had set it to dumping the 
microprogram.  And there, in the EBCDIC decode on the right-hand side of 
the paper, were the words "CROSS PAGE".

Now "pages" are a virtual memory concept, but the 145 didn't _have_ 
virtual memory.  Or so the Principles of Operation (instruction set 
manual) claimed.  Some of our young eager-beavers paid a visit to the 
room set aside for IBM repairmen ("Customer Engineers" or CEs), and 
looked through the microprogram listings.

Lo and behold, there were _gaps_ in the listings, places where the 
counter would jump several hundred or thousand locations.  We dumped 
those sections, figured out the way the microprogram worked from the 
listings, and found something "verrry interessing": the microprogram 
came with complete virtual memory facility, nearly an exact duplicate of 
the 360/67 (the only virtual memory machine in the System/360 series). 
It turned out to be controlled by a sense wire.  Now... cutting that 
wire would have voided the warranty and caused all sorts of trouble.

The result was a program called "wishbone", a fairly thin deck of cards 
that sat in a drawer near the machine.  Stick that deck in the card 
reader, dial 00C into the IPL address, and reboot the machine.  It would 
load a small program into the _control registers_, which were inside the 
microprogram address space.  Then you dialed in a certain address, 
pushed "Set Microprogram Address" and "Go", and it would run the code. 
It patched the microprogram to ignore that sense wire, after which the 
machine had full virtual memory capability.  And in fact experimentation 
showed it would run IBM's virtual machine OS, CP/67, unmodified.

We used it to add paging to the OS we were maintaining.  A few months 
later, the CE came out and clipped that wire and IBM admitted that they 
had Virtual Memory in the 145 and released the first version of VM/370 
to go with it.

   [ As I recall there was a similar "magic" jumper in the PDP 11/70.

     But maybe my favorite "hardware based" upgrades were in the old
     Code-A-Phone 700 answering machine that was the standard Bell
     System model for many years.  This was not only the unit that
     was used extensively throughout the Bell System, but was the
     only "legal" answering machine you could use as an AT&T customer
     in the years prior to legal connection of customer-owned
     equipment.

     The 700 has a gray metal case, weighs a bundle, and is built
     like a battleship.  It doesn't have features like remote message
     access which really didn't exist at that time, but could record
     outgoing messages of up to (I think) three minutes, and record
     two hours of incoming messages.  But that depended on how
     much you paid.

     They could only be rented per month.  Depending on how much
     you paid, the maxiumum outgoing and incoming message times would
     be appropriately limited.  This was controlled by a pair of
     mechanical dials and levers in the unit, that artifically set
     the max length of both tape units.  As you might guess, it quickly
     became widely known how these limits were controlled, and it was
     common for users to set them to their maximums as soon as 
     telco installers had walked out the door.

     I have a number of somewhat amusing stories about the 700, but they
     can wait for another day.

       -- Lauren Weinstein
          NNSquad Moderator ]