On 6/3/11 12:18 PM, "Zane H. Healy" <healyzh at aracnet.com> wrote: I was playing with the virtual PDP-10 this afternoon and a few minutes ago I was reading an article on Slashdot about Robert Cringley taking a poke at IBM's claim to have invented the personal computer. Cringley disagrees and in the process, links to a Wikipedia article about Ed Roberts and MITS. Then, I remembered that Gates and Allen wrote BASIC for the Altair 8800 using a cross-assembler running on a PDP-10 at Lakeside School. So here's the punch line. Does anyone know if someone ever recreated an 8080 emulator to run on the PDP-10 (under SIMH, since I don't have a PDP-10)? Rich -- Rich Cini Collector of Classic Computers Build Master and lead engineer, Altair32 Emulator http://www.altair32.com http://www.classiccmp.org/cini

On 6/17/11 11:20 PM, "Zane H. Healy" <healyzh at aracnet.com> wrote: projects they were involved in): "Ported an 8080 simulator written in FORTRAN 77 from a DECSystem-10 running TOPS-10 to an IBM 4381 mainframe running VM/CMS." Interesting comment. I wonder if that's how Gates/Allen would have done it. Rich -- Rich Cini Collector of Classic Computers Build Master and lead engineer, Altair32 Emulator http://www.altair32.com http://www.classiccmp.org/cini

From: Zane H. Healy Sent: Friday, June 17, 2011 8:21 PM At 11:02 PM -0400 6/17/11, Richard Cini wrote: DISCLAIMER: I work for Paul Allen. Living Computer Museum is heavily based around his collection of vintage mainframes and minicomputers. Several years prior to the creation of the MITS Altair, Paul Allen and Bill Gates started a company called Traf-O-Data, whose product was to be an 8008 (NB: Eight Zero Zero Eight) computer that processed the data gathered by those counter boxes with pneumatic hoses strung across streets. They hired an engineer to create the hardware, but in the mean time needed to program the software. Paul created a simulator for the 8008 which worked as follows: 1. He created a series of Macro-10 macros to interpret 8008 mnemonics into PDP-10 words, with each word containing a UUO in the left half and an 8-bit 8008 byte in the right half. 2. He wrote a UUO handler to interpret the result on the PDP-10, for debugging, along with adding appropriate code to DDT to interpret words in this format as 8008 instructions. (The latter unfortunately has been lost. He would really really like to find it again.) 3. He wrote a routine to punch the 8-bit data to a paper tape punch on the PDP-10 (or on a TTY), for loading into the Traf-O-Data computer. He wanted Bill Gates to work with him on a BASIC for the 8008, but Bill convinced him that the processor was too limited (14 bits of address, 7 levels of a hardware stack, etc.). When the 8080 came along, he revisited the BASIC question, but Bill wanted to wait for someone to build a computer using the chip. When the Altair 8800 came along, Bill agreed to the project. Once they had a commitment from MITS to look at their BASIC, Paul updated his 8008 simulator to handle the 8080 and they began writing the first version of Altair BASIC (along with Monte Davidoff, whom the brought in to write the math library because he had done that in high school for TSS/8). A lot more detail is available in Paul's book _Idea Man_ (http://www.amazon.com/Idea-Man-Memoir-Cofounder-Microsoft/dp/1591843820/ref…)&sr=1-1). Rich Alderson Vintage Computing Sr. Server Engineer Vulcan, Inc. 505 5th Avenue S, Suite 900 Seattle, WA 98104 mailto:RichA at vulcan.com mailto:RichA at LivingComputerMuseum.org http://www.LivingComputerMuseum.org/

From: Richard Cini Sent: Monday, June 20, 2011 5:42 PM Hi, RichC, I'm afraid not. The original code is the private property of Paul Allen, though Microsoft used later versions in its language business for many years. (A friend of mine was the maintainer/developer of Microsoft's tool chain back in the 1970s and 1980s. He appears in the famous picture of the team from Albuquerque.) We have talked to Mr. Allen about the possibility of making this available, but he has not responded either way. He used the simulator and original source code to create the Altair BASIC which he demonstrated during his interview with Leslie Stahl on 60 Minutes, so a working copy (other than the DDT) does exist. We'll announce its availability, when and if we get permission to put it up. Rich Alderson Vintage Computing Sr. Server Engineer Vulcan, Inc. 505 5th Avenue S, Suite 900 Seattle, WA 98104 mailto:RichA at vulcan.com mailto:RichA at LivingComputerMuseum.org http://www.LivingComputerMuseum.org/

On 6/17/11 8:02 PM, Richard Cini wrote: It was written on Harvard's PDP-10 long after they were out of high school.