Problem Installing Ultrix on DECstation 2100

[Sean Caron]

I am pretty sure the DECstation 2100/3100 is old enough that it requires a
512 byte sector CD-ROM to boot and/or install properly. I find some of the
older DEC machines are kind of picky... using a genuine DEC RRD drive will
almost guarantee you to succeed; early CD-ROM drives from other workstation
vendors of the same era (i.e. Sun) are also good bets. Most drives you will
pull from Macs or PCs of the era are set up to do 2048 byte sectors and are
no good for booting the old workstations (though they may work as a simple
peripheral to read CD-ROMs after the fact).

In fact, exactly this sort of thing happened last time I loaded a
VAXstation 3100 (with VMS, but, same principle) over the summer... IIRC, I
tried to boot it with a Sun drive first (note: 512 byte sector drive!) and
it actually booted the miniroot OK, but it always would fail when trying to
restore the save set to the disk. It only worked all the way through once I
put the Sun drive away and started using a DEC RRD45. Use an AppleCD 300
(2048 byte sectors) and it won't even boot the miniroot. So, just an
example of exactly how picky they can be ;)

I kind of miss my old DECstation 2100/3100s... Had a few maybe 15 years
ago. I ran NetBSD on mine... they were slower than dirt but I always
enjoyed staring into that big old black hole of a monitor that was the
VR290 hooked up to it... and I just love that font that DEC used for text
mode. I didn't think of it as such at the time, but the machine is kind of
historically significant; I think it was one of the first MIPS based
machines to sell in real volume.

Best,

Sean


On Sat, Dec 13, 2014 at 7:58 PM, Peter C. Wallace <pcw at mesanet.com> wrote:

> On Sun, 14 Dec 2014, Robert Jarratt wrote:
>
>  Date: Sun, 14 Dec 2014 00:17:52 -0000
>> From: Robert Jarratt <robert.jarratt at ntlworld.com>
>> Reply-To: "General Discussion: On-Topic and Off-Topic Posts"
>>     <cctalk at classiccmp.org>
>> To: "General Discussion: On-Topic and Off-Topic Posts" <
>> cctalk at classiccmp.org>
>> Subject: Problem Installing Ultrix on DECstation 2100
>>
>>
>> (apologies to those on the DecTec list, looking to widen the audience)
>>
>>
>>
>> I am struggling to surmount a problem installing Ultrix 4.5 from a CD-ROM
>> onto a DECstation 2100 (MIPS)
>>
>> After choosing the type of installation (basic or advanced) it tries to
>> offer the system disk selection. However, it keeps failing because it is
>> detecting the CD-ROM drive and saying it has an invalid block size. I can
>> hear it spin up the hard disk that I want to install on, so it should be
>> finding a suitable hard disk, but it looks like it keeps choking on the
>> CD-ROM drive. I can't tell if it is failing to see the hard disk properly,
>> but when I tried NetBSD on the same disk, and in the same machine, it is
>> fine, so the hard disk shouldn't be the problem.
>>
>>
>
> Is it a DEC CD-ROM drive? I think the blocksize must be 512 bytes but
> generic CD-ROM drive have a 2K? block size. Somes drives have a jumper that
> sets the block size.
>
>
>>
>> Any ideas on how to resolve this?
>>
>>
>>
>> Thanks
>>
>>
>>
>> Rob
>>
>>
>>
>>
> Peter Wallace
> Mesa Electronics
>
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