Doesn’t time fly by? The Z80 processor could be bought in July 1976. It
along with Intel’s 8080 were the backbone of classic computing 50 years ago.
Happy computing,
Murray 😊
Yes, I did early development on both. At least the interface to the OS was Pascal. I still have the early documentation buried in a box somewhere.
Sent from my iPhone
> On Jun 20, 2026, at 2:02 PM, Fred Cisin via cctalk <cctalk(a)classiccmp.org> wrote:
>
> On Sat, 20 Jun 2026, ben via cctalk wrote:
>> PL/1 and C are the only two high level languages a operating system is written in, that I can think of that are well documented, and easily found on the WEB.
>
> I heard that all of the Lisa OS, and much of Macintosh, were written in Pascal. (obviously other than some low-level drivers and performance critical routines?)
> Is that correct?
>
> http://pascal.hansotten.com/apple-lisa-pascal/
>
> When did Macintosh development switch to C?
>
> --
> Grumpy Ol' Fred cisin(a)xenosoft.com
There have been a few versions of the utility imd2raw.c floating around
that will take Dave Dunfield's ImageDisk-created images (i.e. an .IMD file)
and make a linear binary image devoid of any metadata. This is similar to
the function of Dave's IMDU.COM program's /b switch.
I've corrected a problem with the assumption that all imd2raw.c descendants
to date have made: sectors that have a skew (i.e. not 1-1 interleaved)
weren't linearized correctly. The skewed sectors need to be written out in
"sorted" order, which is not necessarily captured/physical order. This is
easily verified by comparing output from "IMDU /b" to earlier imd2raw
outputs on any .IMD that has a sector skew that isn't 1, 2, 3 [...].
It's up on github here:
https://github.com/RetroFloppy/imd2raw
I found a Magellan Roadmate 2000 in a box in my basement.
It doesn't light up when I connect it to a USB charger (not the port on
my computer). Maybe it has a dead (not simply discharged) battery.
Maybe it's a brick.
If you want it, send a PDF for a small Postal Service Flat Rate box.
Van Snyder
This has mushroomed and I'm so glad to have the opportunity to reveal
the entire mess here:
The Alpha XP900's PCI cage is no different than any 90's cage.
It uses PnP, it accepts and assigns cards intelligently and properly.
it has no discrete tool, like a 90's PC, but it is the same.
If you get it confused with a stupid cage-stuff:
Take all the cards out. Stuff the cage with RTL nics or VIA
usb cards, neutral, friendly, the bus will love them. If it makes you
feel better, boot bsd and run them on the bus. There's no way the cage
remembers anything after that. This problem never happens, but there's
your fix.
To propery orient the machine, prefetch_mode should be off for the
first probe by the booted OS, even if it crashes your machine. Then
turn it back on and boot again. This clinches the PCI cage and the EV6
bus through Pchip etc....
The problem open-source developers had was they could not be certain of
the hardware config. I can be.
They were bouncine their code off of unknown hardware and, having
nothing to hang their hat on, eventually quit, blaming the hardware.
Each time they ran a squirrely, unfenced driver, they skewed the bus
for everything. It was untestable. I think I destroyed a (very cheap)
Si3114ctu controller chip with netbsd's satalink driver. I got
80meg@sec (lucky boot) and beat the hell out of it, then it up and
died.... I think all the extra traffic and work involved literally
worked the chip to death. Add this to the mix as a possibility and it
re-enforces in the mind of userland the machine is junk.
So the ultimate answer is that the Open-Source Community, userland
specifically, screwed the pooch for every weak-memory-model
architecture they ever ported to, by ignoring page one of the Alpha
architectural white-paper.
NetBSD, OpenBSD, FreeBSD, and Linux kernels always booted because they
were written for the Alpha and obeyed the need for memory barriers to
enforce in-order messages to the card-cage. All userland But Drivers
use kernel for thier work and are thus protected by (netbsd's)
Bus_space(), or other similar mechanism.
The Tsunami does't give a hoot what order things come to it, but PCI is
linear and it sure does.
Since the kernels were all compiled with memory barriers, why doesn't X
run on any of them? Why does the onboard ata controllers on the Alpha
machines universally throw orphan (stray) irq's and downgrade to PIO
mode 4 after initial negotiation at UDMA2?
Userspace is not compiled with memory barriers at all. Xorg just pukes
out of order garbage at the pci cage and stuns the video card, crashes
the entire bus as often as not.
This is All the BSD's and All the Linux.
It is vital that these folks do something, for Risc V has a weak memory
model.
The Alpha is by far not alone:
The PowerPC FX970 also suffers from this, but the iMac G5 is a very
tightly integrate machine with no expandability and so survives the
bus-storms, but they are there in userspace, sure as God made little
green apples.
I don't think it helps performance at all on PARisc....
All of these would benefit from increased stability and better disk and
network IO! if userspace were properly curated.
The Alpha was just the First victim of a blind-spot so enormous it is
hard for me to credit, but every time I look at a release, I see the
same sin, over and over and over. No Bus_space(), no Alpha_mb()
ANYWHERE but the kernel(s).
Some new discoveries in-the-bud:
I feel very strongly that prefetch_mode in the srm does Not require
INIT to toggle. I think it is toggleable from there as often as you
like, in fact I think it is toggleable at a speed measured in at least
the kilohertz....
I think this is the toggle, with another one or two, maybe, which NT
and OpenVMS and Tru64 are able to achieve such good performance on a
bus which requires in-order data and is hanging in a bag off of the
Tsunami bus....
I think that these three operating systems have discrete rules they
enforce using these toggles. We don't know where they are, but
prefetch is one we do and perhaps can probe for in memory....?
Even if this dynamic mechanism is unreal ( I think it is real ), or
even if we can't exploit it (very likely, especially in short-term), it
doesn't really matter. We've always accepted Some penalty for open-
source and with the proper build it will run very very well with no
need to resort to the above speculated optimizations.
So, in short, the Alpha is clean. The hardware is good. Modern
hardware worke Better than period because it knows PnP better, but it
all works unless you are just a mad bomber.
All the BSD's and linux's work. NetBSD 9.2 works best by far on this
machine. I had X running for a week on a lucky boot with a clean cage
and a following wind. Heavy compiling all week (over a very quiet and
well-behaved Intel 1000 pro lan card).
I'm not a coder so the software side is up-hill, but I'll get there.
My first goal is to try and patch the wd0 driver for memory barriers.
I expect it will instantly negotiate to PIO4 UDMA2 and stay there
without any 'stray interrupt 14, stray interrupt 15' garbage in
console. That will validate this entire sad episode and I'll do it
first if someone doesn't beat me to it.
Please dig out your Alphas. There was nothing wrong with them to begin
with.
On my Facebook post I inluded some photos of a pirate copy of High-
Performance Computer Architecture, by Harold Stone. It is a clean-room
copy, a re-set, and there is only one in the world. I would love to
show this to Mr. Stone and tell him how it came to be. Here's a link
to a couple of pages of it:
https://www.facebook.com/groups/retrocomputers/posts/28340501522219693
Thanks for listening, thanks for being here all these years.
I didn't realize until this other day, but the list started about the
time I joined it, around 1998/2000. Then we were just a bunch of
geeks, but today classicmp is an institution, venerable and respected.
BZ!
.
BZ!On Tue, 2026-07-07 at 12:00 -0500, cctalk-request(a)classiccmp.org
wrote:
> Send cctalk mailing list submissions to
> cctalk(a)classiccmp.org
>
> To subscribe or unsubscribe via email, send a message with subject or
> body 'help' to
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>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of cctalk digest..."
>
> Today's Topics:
>
> 1. Re: DEC Alpha EV6 (Tsunami) PCI pbus cohere. (David Brownlee)
>
>
> ---------------------------------------------------------------------
> -
>
> Message: 1
> Date: Mon, 6 Jul 2026 19:30:59 +0100
> From: David Brownlee <abs(a)absd.org>
> Subject: [cctalk] Re: DEC Alpha EV6 (Tsunami) PCI pbus cohere.
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk(a)classiccmp.org>
> Cc: "Jeffrey S. Worley" <technoid6502(a)gmail.com>
> Message-ID:
> <
> CAGN_6pbu=vbeDrQ5M6Urf+mkK642EDZaamugv08Mf_yk81f7Xg(a)mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
>
> On Fri, 26 Jun 2026 at 03:24, Jeffrey S. Worley via cctalk
> <cctalk(a)classiccmp.org> wrote:
> >
> > Today I decided to test the bus-cohere protocol with cards other
> > than
> > framebuffer and IT WORKS.
> >
> > SRM won't let me boot from it of course, but I:
> >
> > [... happy happy Alphe EV6 NetBSD 9.2 boot process complete with
> > x11 ...]
>
> Very cool news :)
>
> Presumably this could be incorporated directly into the alpha kernel
> initialisation - if on a model that requires it the kernel could
> pause
> before probing the PCI bus?
>
> David
>
> End of cctalk Digest, Vol 1224, Issue 1
> ***************************************On Tue, 2026-07-07 at 12:00 -
0500, cctalk-request(a)classiccmp.org wrote:
> Send cctalk mailing list submissions to
> cctalk(a)classiccmp.org
>
> To subscribe or unsubscribe via email, send a message with subject or
> body 'help' to
> cctalk-request(a)classiccmp.org
>
> You can reach the person managing the list at
> cctalk-owner(a)classiccmp.org
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of cctalk digest..."
>
> Today's Topics:
>
> 1. Re: DEC Alpha EV6 (Tsunami) PCI pbus cohere. (David Brownlee)
>
>
> ---------------------------------------------------------------------
> -
>
> Message: 1
> Date: Mon, 6 Jul 2026 19:30:59 +0100
> From: David Brownlee <abs(a)absd.org>
> Subject: [cctalk] Re: DEC Alpha EV6 (Tsunami) PCI pbus cohere.
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk(a)classiccmp.org>
> Cc: "Jeffrey S. Worley" <technoid6502(a)gmail.com>
> Message-ID:
> <
> CAGN_6pbu=vbeDrQ5M6Urf+mkK642EDZaamugv08Mf_yk81f7Xg(a)mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
>
> On Fri, 26 Jun 2026 at 03:24, Jeffrey S. Worley via cctalk
> <cctalk(a)classiccmp.org> wrote:
> >
> > Today I decided to test the bus-cohere protocol with cards other
> > than
> > framebuffer and IT WORKS.
> >
> > SRM won't let me boot from it of course, but I:
> >
> > [... happy happy Alphe EV6 NetBSD 9.2 boot process complete with
> > x11 ...]
>
> Very cool news :)
>
> Presumably this could be incorporated directly into the alpha kernel
> initialisation - if on a model that requires it the kernel could
> pause
> before probing the PCI bus?
>
> David
>
> End of cctalk Digest, Vol 1224, Issue 1
> ***************************************
On Wed, 8 Jul 2026, Kevin McQuiggin wrote:
> Nice to see some photos. I have only ever read about RAMAC and the only photos I have seen are IBM marketing photos from the late 50s/early 60s.
The one that Dennis Boone posted is not bad:
https://gallery.porterstreetcafe.com/vcfmw/2007/slide_71.html
In 1958?, Nikita Khrushchev visited USA to try to calm the cold war a
little.
He wasn't allowed to go to Disneyland!
He was a little upset. "Is there an outbreak of cholera? Have gangsters
taken it over, who might harm me?" etc.
He was given an incredible dinner in Hollywood. Mrs. Khrushchev expressed
disapointment about not going. Sinatra said to Niven, "Tell the old broad
that you and I will take her there, personally"
To make up for it, they took him to the IBM facility in San Jose, and
showed him Ramac construction. He was more impressed with the
efficiency of the self service cafeteria.
I think that the Cuban missile crisis would have been a lot less tense if
they were to have let him go to Disneyland!
New Yorker ran a cartoon that showed a submarine surfacing off shore, and
a fat man sneaking to Disneyland.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
All,
A number of years ago, I ended up with a pile of MXV22M QBus controllers, which present a RXV21 compatible interface to the QBus, but talk to 5.25" diskettes. Thanks to a generous loan of a regular MXV22 from John Ball, I was able to convert the MXV22M to a regular MXV22:
http://users.glitchwrks.com/~glitch/2026/07/12/mti-mxv22m-conversion
The above writeup includes links to the fuse PROM images.
I'd like to build a mezzanine to replace the 7x fuse PROMs with modern EEPROM or Flash, but haven't had time to get on it, other than verifying that the original fuse PROMs aren't so fast as to make that impossible.
If you have blank fuse PROMs but no way to program, contact me off-list and I can blow a set on the Data I/O 29B.
I will be going through the MXV22Ms I have and converting them, as time permits, and then making them available for sale. If you want an untested MXV22M to convert yourself (cheaper if I don't have to!) then contact me off-list and let me know.
Thanks,
Jonathan
We can stand in awe as classic computerists at the advancement of
technology: I recently read that chip technology size is at 2 nanometers
for ultra-large scale processors. In 1971 it was 10,000 nanometers or 10
microns. This is a 5000x reduction in size in 55 years. One has to ask: Is
Moore’s Law still alive?
Happy computing?
Murray :-)
