Re:A 1958 UNIVAC airline reservation system
by YeGoblynQueenne on Sunday November 07, 2021 @04:35AM
(#29137832)
Yeah, I was alluding to The Story of Mel, a Real Programmer :)
Funny thing though, about the story. Neither the RPC-4000 [1], nor the LGP-30 [2] had an index resiter and the RPC-4000 didn't have an unconditional jump instruction (since "every single instruction was followed by a GO TO!"). The LGP-30 instruction word had two bits between opcode and operand, but the RPC 4000 had none. So Ed Nather's retelling of the hack wouldn't have been possible exactly as he describes it on either computer.
It turns out that Royal McBee had someone design an emulator for the LGP-30 to run on he RPC 4000, that could have ran Mel Kaye's blackjack program [3]. My guess is that Ed Nather is mixing up the two architectures in his mind because of that. Perhaps he was asked to modify Mel Kaye's program to run on the _emulated_ LGP-30 and the details of the two architectures got fudged in his memory. He's writing the story 23 years later so he's entitled to forget some details, I guess.
My name is James William (Bill) Bryner ... In 1960 I was hired by Royal-McBee to write the assembler for the replacement to the LGP-30, the RPC-4000.
Mel Kaye designed the RPC-4000 assembler. It was titled ROAR (Royal-McBee Optimizing Assembler Routine). Edward W. Dubbs and I programmed that assembler. Following that, I wrote an LGP-30 simulator to run on the RPC-4000. This was meant to allow all programs written for the LGP-30 to be executed on the RPC-4000 without further programming. A drum computer simulating a drum computer is agonizingly slow!
Funny thing though, about the story. Neither the RPC-4000 [1], nor the LGP-30 [2] had an index resiter and the RPC-4000 didn't have an unconditional jump instruction (since "every single instruction was followed by a GO TO!"). The LGP-30 instruction word had two bits between opcode and operand, but the RPC 4000 had none. So Ed Nather's retelling of the hack wouldn't have been possible exactly as he describes it on either computer.
It turns out that Royal McBee had someone design an emulator for the LGP-30 to run on he RPC 4000, that could have ran Mel Kaye's blackjack program [3]. My guess is that Ed Nather is mixing up the two architectures in his mind because of that. Perhaps he was asked to modify Mel Kaye's program to run on the _emulated_ LGP-30 and the details of the two architectures got fudged in his memory. He's writing the story 23 years later so he's entitled to forget some details, I guess.
_______________________
[1] http://www.bitsavers.org/pdf/royalPrecision/RPC-4000/RPC-400...
[2] http://ed-thelen.org/comp-hist/lgp-30-man.html
[3] http://ed-thelen.org/comp-hist/lgp-30.html#Historical%20Note...
See the following comment:
My name is James William (Bill) Bryner ... In 1960 I was hired by Royal-McBee to write the assembler for the replacement to the LGP-30, the RPC-4000.
Mel Kaye designed the RPC-4000 assembler. It was titled ROAR (Royal-McBee Optimizing Assembler Routine). Edward W. Dubbs and I programmed that assembler. Following that, I wrote an LGP-30 simulator to run on the RPC-4000. This was meant to allow all programs written for the LGP-30 to be executed on the RPC-4000 without further programming. A drum computer simulating a drum computer is agonizingly slow!