Talk:Prime Computer

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I have no direct experience with Prime Computer. But I did work in the Massachusetts hi-tech industry during the Massachusetts Miracle era when Prime was one of the big 4 computer vendors in the region. I created this page from the information in the 2 external links. Hopefully, somebody with more direct Prime Computer experience will fix up whatever inaccuracies that exist on this page. Dyl 23:46, Aug 16, 2004 (UTC)

Contents

[edit] Specialised Software Section

I have created this section since I was in the UK the arketing manager for Prime's OAS and Prime Information Connection. There are citations needed, and I will see what I can achieve with those over time.

Fiddle Faddle 21:27, 26 April 2006 (UTC)


[edit] Microcode from floppy

One of the most interesting things to me about Prime computers (at least ones that I worked with for a while) and the PRIMOS OS, was that the actual main CPU didn't boot immediately when the system was switched on; what you saw on the console terminal was the VCP, the Virtual Control Program (if memory serves me). The VCP was a small microprocessor-based computer-in-the-computer and it booted from a 5.25" floppy disk (at least on the 2550 and I think on the 9955) and was in charge of downloading the microcode from another floppy disk to the main CPU which was a two-board unit that contained many chips (I remember recognizing a bunch of Z80s on the main CPU board of the 2550) so not just one chip as we would expect from a CPU nowadays.

After the microcode was downloaded into the main CPU, the computer could boot from a tape or from harddisk; something that would take approximately 20 minutes on our systems. I wonder how many support calls they got from people who shut down their Prime for some reason and then discovered that they couldn't restart it because one of the floppy disks (which weren't used for any other purpose) were missing from the two full-size drives, or unreadable because the drives had gotten dusty. Anyway later on (at least in the 2350) they replaced the floppy disk drives by a small custom-made circuit board with EPROMs which was plugged into the back of the machine.

Jac Goudsmit 0:46, 05 June 2007 (UTC)

You do know why the floppy disk was invented, right? Guy Harris 22:47, 13 June 2007 (UTC)

[edit] Microcode; also memory map

Loading the processor microcode from floppy was also charactoristic of the DEC VAX 11/780.

Another wierd thing - some of the bootup parameters required specific parts of the memory map to be "hard wired" - pieces of the map dedicated to some specific applications running on that particular machine. Don't remember much else, it's been a while. RobertTaylor21 21:06, 13 June 2007 (UTC)

[edit] Added Photo

Added photo of a real Prime 9950 with Console monitor. Taken in 1988. Took awhile to find this old photo.

--akc9000 (talk • contribs • count) 00:16, 6 July 2007 (UTC)