From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Arnold Message-Id: <7BBE2FFB-21F5-469C-B06F-D9C4C1E0AA57@pobox.com> Content-Type: multipart/signed; boundary="Apple-Mail=_67ECB9EE-F051-4297-8358-120CD4C063CC"; protocol="application/pgp-signature"; micalg=pgp-sha256 Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Date: Tue, 9 Oct 2018 14:16:51 +1100 In-Reply-To: To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> References: Cc: David Arnold Subject: Re: [9fans] PDP11 Topicbox-Message-UUID: e91467cc-ead9-11e9-9d60-3106f5b1d025 --Apple-Mail=_67ECB9EE-F051-4297-8358-120CD4C063CC Content-Type: multipart/alternative; boundary="Apple-Mail=_13E437F3-47B9-4864-A830-026FBA2062ED" --Apple-Mail=_13E437F3-47B9-4864-A830-026FBA2062ED Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On 9 Oct 2018, at 14:08, Digby R.S. Tarvin wrote: <=E2=80=A6> > So I don't think it i would be worth a substantial rewrite to get it = going. It is a shame that there don't seem to have been any more = powerful machines with a comparably elegant architecture and attractive = front panel :) >=20 > An attractive front panel for nearly any machine is just a soldering = iron, LEDs and some logic chips away. As far as elegant architectures, = some are very nice: MIPS is kind of retro but elegant, RISC-V is nice, = 680x0 machines can be had a reasonable prices, and POWER is kind of = cool. I know I shouldn't, but I have a soft spot for ARM. >=20 > I have thought about it, but there are a couple of problems (in = addition to my lack artistic talent when it comes to building physically = attractive enclosures).. One is the sheer number of LEDs required to = display all of the address and data lines in a modern architecture. = Mainly an issue if I want to use the old PDP11/70 front panel that I had = saved for the purpose, I suppose. The other problem is getting access to = the all of the machine state that was displayable on a mini computer = console. Virtual addresses, User/Kernel mode, register contents etc are = all hard to get at. I have toyed with using JTAG etc, but there always = seems to be something that I can't get to. So it is hard to do more than = resort to a software controlled front panel. I used to have a little box = of LEDs and switches that I plugged into the parallel port on PCs, and = had my BSDi kernel modified to update it as part of the clock interrupt. = But now the parallel ports are becoming rare and you can't update LEDs = connected via USB in a single instruction... :-/ Probably not quite what you=E2=80=99re after, but the PiDP8 and PiDP11 = kits will get you an (arguably) attractive front panel without requiring = artistic talent. http://obsolescence.wixsite.com/obsolescence/pidp-11 I=E2=80=99ve not looked into how the front-panel is driven (from SIMH, I = guess?), but perhaps it could be suitably massaged? d --Apple-Mail=_13E437F3-47B9-4864-A830-026FBA2062ED Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
On = 9 Oct 2018, at 14:08, Digby R.S. Tarvin <digbyt42@gmail.com> = wrote:

<=E2=80=A6>

So I don't think it i would be worth a = substantial rewrite to get it going. It is a shame that there don't seem = to have been any more powerful machines with a comparably elegant = architecture and attractive front panel :)

An attractive front = panel for nearly any machine is just a soldering iron, LEDs and some = logic chips away. As far as elegant architectures, some are very nice: = MIPS is kind of retro but elegant, RISC-V is nice, 680x0 machines can be = had a reasonable prices, and POWER is kind of cool. I know I shouldn't, = but I have a soft spot for ARM.

I have thought about it, = but there are a couple of problems (in addition to my lack artistic = talent when it comes to building physically attractive = enclosures)..  One is the sheer number of LEDs required to display = all of the address and data lines in a modern architecture.  Mainly = an issue if I want to use the old PDP11/70 front panel that I had saved = for the purpose, I suppose. The other problem is getting access to the = all of the machine state that was displayable on a mini computer = console. Virtual addresses, User/Kernel mode, register contents etc are = all hard to get at. I have toyed with using JTAG etc, but there always = seems to be something that I can't get to. So it is hard to do more than = resort to a software controlled front panel. I used to have a little box = of LEDs and switches that I plugged into the parallel port on PCs, and = had my BSDi kernel modified to update it as part of the clock interrupt. = But now the parallel ports are becoming rare and you can't update LEDs = connected via USB in a single instruction... = :-/

Probably = not quite what you=E2=80=99re after, but the PiDP8 and PiDP11 kits will = get you an (arguably) attractive front panel without requiring artistic = talent.

<= div>
I=E2=80=99ve not looked into how the = front-panel is driven (from SIMH, I guess?), but perhaps it could be = suitably massaged?



d

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