On 09/18/2018 12:43 PM, Stewart Russell via talk wrote:
On Tue, Sep 18, 2018, 10:48 James Knott via talk, <talk@gtalug.org <mailto:talk@gtalug.org>> wrote:
I also used to maintain a PDP-8i computer. When browsing through the programming manual, I found DEC actually recommending self modifying code, to get around the limitations of the instruction set!
The basic PDP-8 didn't have a hardware stack, so you had to prepare subroutines by modifying the code's return address before you called it.
I'm building a PDP-8 compatible right now, based on the Harris HD-6120 "PDP-8 on a chip" used in the DECMate desktops. I'd best brush up my octal, as it's a 12-bit machine.
Being a hardware tech, I didn't really get into software. However, I found on my IMSAI, with the 8080 CPU, working in octal was better than hex, as the digits lined up with the instruction fields. They didn't with hex. I just tried to dig up an article I read in Byte magazine about that chip, but couldn't find it. However, I did find an article that, in addition to mentioning the PDP-8, included this: And Ethernet's Fate? A report issued by Strategic Incorporated, a market-research firm in San Jose, California, predicts Xerox Corporation's Ethernet local-area network will be a total failure within two years. According to Strategic's president, Michael Killen, "Xerox is headed for the worst failure in the company's history." He believes that Xerox lacks technological and price advantages, sales force, and customers interested in buying large systems. Further, he contends that Ethernet's baseband approach to local networking will prove inferior over the long haul to the broadband approach taken by Xerox's competitors. He points out that broadband systems are better suited to carry video, heavy voice and data transmissions, among other applications. In response to the report, Xerox issued the following statement: " Based on the level of customer satisfaction with our existing network installations, the backlog of orders for network products and service, and the interest in Ethernet on the part of major accounts, we are confident that Xerox will be a leading vendor in office automation." I suspect that report was a bit off the mark! ;-) https://tech-insider.org/personal-computers/research/acrobat/8203.pdf