9 Sep
2025
9 Sep
'25
5:52 p.m.
I just love the PDP11's assembly language. I needed a super-tight
subroutine to print a 16-bit value as 6 octal digits. This is as tight as I
could make it, 16 words (including writing to the serial port, which takes
5 words). Can you beat it?
;*** Subroutine *************************
;Print a 16-bit value as 6 octal digits
;Calling Sequence:
; jsr PC,PROCT6
;On Entry:
; R2 = value to print
;Trashes R1,R2
;****************************************
PROCT6: mov #100030,R1 ;Digit loop ends when '1' lands in C
;..'30' makes it ASCII
sec ;All done when this is in C again
;Extract a digit and convert it to ASCII. Check for done.
1$: rol R2 ;Shift digit out of R2 & into R1
beq 3$ ;Return when done
rol r1 ;Build next octal digit
bcc 1$ ;Done when c = shift pattern bit
;Write digit to the serial port
2$: tstb @#CTXSTA ;Wait for transmitter (clears C)
bpl 2$
movb R1,@#CTXDAT ;Transmit now
;Next digit
mov #020006,R1 ;Digit ends when "2" lands in C.
;Printing ends when "sec" bit
;..leaves R2. '6' makes ASCII
br 1$
3$: rts PC
Martin E.
10 Sep
10 Sep
6:32 a.m.
On Sep 9, 2025, at 8:52 PM, Martin Eberhard via cctalk
<cctalk(a)classiccmp.org> wrote:
I just love the PDP11's assembly language. I needed a super-tight
subroutine to print a 16-bit value as 6 octal digits. This is as tight as I
could make it, 16 words (including writing to the serial port, which takes
5 words). Can you beat it?
;*** Subroutine *************************
;Print a 16-bit value as 6 octal digits
;Calling Sequence:
; jsr PC,PROCT6
;On Entry:
; R2 = value to print
;Trashes R1,R2
;****************************************
PROCT6: mov #100030,R1 ;Digit loop ends when '1' lands in C
;..'30' makes it ASCII
sec ;All done when this is in C again
;Extract a digit and convert it to ASCII. Check for done.
1$: rol R2 ;Shift digit out of R2 & into R1
beq 3$ ;Return when done
rol r1 ;Build next octal digit
bcc 1$ ;Done when c = shift pattern bit
;Write digit to the serial port
2$: tstb @#CTXSTA ;Wait for transmitter (clears C)
bpl 2$
movb R1,@#CTXDAT ;Transmit now
;Next digit
mov #020006,R1 ;Digit ends when "2" lands in C.
;Printing ends when "sec" bit
;..leaves R2. '6' makes ASCII
br 1$
3$: rts PC
Martin E.
Very nice. Here is the code used in the KMON (resident part of the keyboard monitor,
i.e., CLI) of RT-11 V2. I think it was created by Anton Chernoff.
OPRINT: MOV #30,R0 ;CONVERT WORD TO OCTAL AND PRINT IT
SEC
4$: ROL R2 ;DON'T TRY TO UNDERSTAND THIS ROUTINE
ROLB R0 ; JUST USE IT & LOVE IT
.TTYOUT
MOV #206,R0
5$: ASL R2 ;DONE YET ?
BEQ 6$ ;YES
ROLB R0
BCS 5$
BR 4$
6$: <exit>
Same approach but yours is shorter because it forms the next digit in one place rather
than two. Interesting that was missed in the earlier version.
paul
7:46 a.m.
On 9/10/25 08:32, Paul Koning via cctalk wrote:
> On Sep 9, 2025, at 8:52 PM, Martin Eberhard via
cctalk <cctalk(a)classiccmp.org> wrote:
>
> I just love the PDP11's assembly language.
Yes, the PDP-11 machine language was INCREDIBLY brilliant,
and did the very best with what you could do in 16 bits!
Jon
9:02 a.m.
On 2025-09-10 8:46 a.m., Jon Elson via cctalk wrote:
On 9/10/25 08:32, Paul Koning via cctalk wrote:
But even then you could see the hand writing on the wall for 16 bits.
> On Sep 9, 2025, at 8:52 PM, Martin Eberhard
via cctalk
> <cctalk(a)classiccmp.org> wrote:
>
> I just love the PDP11's assembly language.
Yes, the PDP-11 machine language was INCREDIBLY brilliant, and did the
very best with what you could do in 16 bits! Jon
Still waiting for the PDP K.
Ben.
10:34 a.m.
Yep, 16 bits, or even 32 seemed like a lot, If you're writing asm, It is.
But like you alluded to, it's not good enough for the stuff we expect today,
On Wed, Sep 10, 2025 at 9:26 AM ben via cctalk <cctalk(a)classiccmp.org>
wrote:
On 2025-09-10 8:46 a.m., Jon Elson via cctalk wrote:
On 9/10/25 08:32, Paul Koning via cctalk wrote:
But even then you could see the hand writing on the wall for 16 bits.
> On Sep 9, 2025, at 8:52 PM, Martin Eberhard
via cctalk
> <cctalk(a)classiccmp.org> wrote:
>
> I just love the PDP11's assembly language.
Yes, the PDP-11 machine language was INCREDIBLY brilliant, and did the
very best with what you could do in 16 bits!
Jon
Still waiting for the PDP K.
Ben.
1:35 p.m.
On Sep 10, 2025, at 1:34 PM, Jim Davis via cctalk
<cctalk(a)classiccmp.org> wrote:
Yep, 16 bits, or even 32 seemed like a lot, If you're writing asm, It is.
But like you alluded to, it's not good enough for the stuff we expect today,
That depends a lot on what sort of "stuff" you work with.
For various fun projects I use the Raspberry Pico, which is a 32 bit microcontroller with
1/4 or 1/2 MB of RAM, which is quite a lot. But a bunch of that work uses the PIO engines
-- basically programmable state machines that talk to the I/O pins. Those have 16 bit
instructions, and a 32 word program memory. No data RAM, just a couple of registers.
Quite powerful, though. One application is the DDCMP controller I published a while ago.
I'm thinking about making it talk Ethernet in software as the next exercise...
paul
1:45 p.m.
I did 8080 programming and had 16kb to play with.
I thought there would never be a program large enough that 1mb was needed. Hah
Sent from my iPhone
On Sep 10, 2025, at 13:41, Paul Koning via cctalk
<cctalk(a)classiccmp.org> wrote:
On Sep 10, 2025, at 1:34 PM, Jim Davis via cctalk
<cctalk(a)classiccmp.org> wrote:
Yep, 16 bits, or even 32 seemed like a lot, If you're writing asm, It is.
But like you alluded to, it's not good enough for the stuff we expect today,
That depends a lot on what sort of "stuff" you work with.
For various fun projects I use the Raspberry Pico, which is a 32 bit microcontroller with
1/4 or 1/2 MB of RAM, which is quite a lot. But a bunch of that work uses the PIO engines
-- basically programmable state machines that talk to the I/O pins. Those have 16 bit
instructions, and a 32 word program memory. No data RAM, just a couple of registers.
Quite powerful, though. One application is the DDCMP controller I published a while ago.
I'm thinking about making it talk Ethernet in software as the next exercise...
paul
5:56 p.m.
I've been doing embedded my whole career. ESP 32 is my retirement toy. Lots
of C, forth and ASM. I still can't write a python app.
On Wed, Sep 10, 2025 at 1:45 PM Wayne S <wayne.sudol(a)hotmail.com> wrote:
I did 8080 programming and had 16kb to play with.
I thought there would never be a program large enough that 1mb was needed.
Hah
Sent from my iPhone
On Sep 10, 2025, at 13:41, Paul Koning via cctalk
<cctalk(a)classiccmp.org>
wrote:
> On Sep 10, 2025, at 1:34 PM, Jim Davis via cctalk <
cctalk(a)classiccmp.org> wrote:
>
> Yep, 16 bits, or even 32 seemed like a lot, If you're writing asm, It
is.
> But like you alluded to, it's not good
enough for the stuff we expect
today,
That depends a lot on what sort of "stuff" you work with.
For various fun projects I use the Raspberry Pico, which is a 32 bit
microcontroller with 1/4 or 1/2 MB of RAM, which is quite a lot. But a
bunch of that work uses the PIO engines -- basically programmable state
machines that talk to the I/O pins. Those have 16 bit instructions, and a
32 word program memory. No data RAM, just a couple of registers. Quite
powerful, though. One application is the DDCMP controller I published a
while ago. I'm thinking about making it talk Ethernet in software as the
next exercise...
paul
11 Sep
11 Sep
3:10 a.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On 10/09/2025 18:34, Jim Davis via cctalk wrote:
Yep, 16 bits, or even 32 seemed like a lot, If
you're writing asm, It is.
But like you alluded to, it's not good enough for the stuff we expect today,
I believe it was Chuck Moore that said "If you can't do it in 8K it's
not worth doing", before designing the Novix chip with 32K of address space.
1:30 p.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
You can get an emulated 11/23 running 4.2 BSD for $3.00. That's crazy.
On Thu, Sep 11, 2025 at 4:11 AM Frank Leonhardt via cctalk <
cctalk(a)classiccmp.org> wrote:
On 10/09/2025 18:34, Jim Davis via cctalk wrote:
I believe it was Chuck Moore that said "If you can't do it in 8K it's
not worth doing", before designing the Novix chip with 32K of address
space.
Yep, 16 bits, or even 32 seemed like a lot, If
you're writing asm, It is.
But like you alluded to, it's not good enough for the stuff we expect
today,
5:44 a.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
The only machines I used that has blinky lights and switches was my altair
and the old PDP-8 at OMSI.
I have other junk, A Alpha micro with hex pad and a Tek 8002a with switches.
Their 11/45 had lights, but ran RSTS most of the time. Every 11/23 I used
was without front panel.
The machine I'm referring to is the ESP32, USB power, and no case, but you
could print one.
I can almost remember the PDP-8 dectape boot from memory, 50 years later.
Has it been that long?
On Fri, Sep 12, 2025 at 1:26 AM ben via cctalk <cctalk(a)classiccmp.org>
wrote:
On 2025-09-11 2:30 p.m., Jim Davis via cctalk wrote:
You can get an emulated 11/23 running 4.2 BSD for
$3.00. That's crazy.
What device? Power supple, case and front panel all must be extra. Ben.
6:46 a.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On Sep 12, 2025, at 8:44 AM, Jim Davis via cctalk
<cctalk(a)classiccmp.org> wrote:
...
Their 11/45 had lights, but ran RSTS most of the time.
I'm confused by the "but". 11/45s have lights and switches panels, and RSTS
would display a nice lights pattern on that when idle. Many versions could optionally do
a rather amazing lights pattern involving both the address and the data lights
("fancy nuljob").
paul
7:43 a.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On 9/11/2025 4:30 PM, Jim Davis via cctalk wrote:
You can get an emulated 11/23 running 4.2 BSD for
$3.00. That's crazy.
It's crazier than you think. 4.2 BSD doesn't run on the PDP-11.
But I can get 4.whatever running on an emulated VAX or 2.11 BSD
running on an emulated PDP-11 of my choice (I usually do 11/44
cause I had some and really liked them) for free.
bill
13 Sep
13 Sep
7:49 a.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On 9/11/2025 4:30 PM, Jim Davis via cctalk wrote:
You can get an emulated 11/23 running 4.2 BSD for
$3.00. That's crazy.
Can you tell me where? With that glaring error I am really
interested in learning more. Google finds nothing with those
terms.
bill
9:35 a.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On Sep 13, 2025, at 10:49 AM, Bill Gunshannon via
cctalk <cctalk(a)classiccmp.org> wrote:
On 9/11/2025 4:30 PM, Jim Davis via cctalk wrote:
It has to be hyperbole.
No pdp11 ran 4.x, the best you can do is 2.11— which is still being patched and
maintained; see the pidp-11 mailing list. Probably not $3.00, but $30.00 will get you a
sytem on a DIP package that will emulate most anything. Spend a bit more for a Pi4 or Pi5
if you want to drive a PiDP-11.
You can get an emulated 11/23 running 4.2 BSD for
$3.00. That's crazy.
Can you tell me where? With that glaring error I am really
interested in learning more. Google finds nothing with those
terms.
bill
9:59 a.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On 2025-09-13 10:35 a.m., Milo Velimirović via cctalk wrote:
But can you still get a real PDP-11 replacement for driving vintage
hardware?
On Sep 13, 2025, at 10:49 AM, Bill Gunshannon via
cctalk <cctalk(a)classiccmp.org> wrote:
On 9/11/2025 4:30 PM, Jim Davis via cctalk wrote:
It has to be hyperbole.
No pdp11 ran 4.x, the best you can do is 2.11— which is still being patched and
maintained; see the pidp-11 mailing list. Probably not $3.00, but $30.00 will get you a
sytem on a DIP package that will emulate most anything. Spend a bit more for a Pi4 or Pi5
if you want to drive a PiDP-11. You can get an emulated 11/23 running 4.2 BSD for
$3.00. That's crazy.
Can you tell me where? With that glaring error I am really
interested in learning more. Google finds nothing with those
terms.
bill
1:21 p.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On Sep 13, 2025, at 12:59 PM, ben via cctalk
<cctalk(a)classiccmp.org> wrote:
On 2025-09-13 10:35 a.m., Milo Velimirović via cctalk wrote:
But can you still get a real PDP-11 replacement for driving vintage hardware?
Probably not. But I think John Wilson of Ersatz-11 fame created a Unibus (or QBus?)
interface for PCs so E-11 could drive real DEC peripherals.
Given suitable transceivers, it would not be all that hard to create a PDP-11 replacement
with Unibus and/or Qbus capability out of an FPGA. There are working PDP11 emulations for
FPGAs.
paul
On Sep
13, 2025, at 10:49 AM, Bill Gunshannon via cctalk <cctalk(a)classiccmp.org> wrote:
On 9/11/2025 4:30 PM, Jim Davis via cctalk wrote:
It has to be hyperbole.
No pdp11 ran 4.x, the best you can do is 2.11— which is still being patched and
maintained; see the pidp-11 mailing list. Probably not $3.00, but $30.00 will get you a
sytem on a DIP package that will emulate most anything. Spend a bit more for a Pi4 or Pi5
if you want to drive a PiDP-11. You can get an emulated 11/23 running 4.2 BSD for
$3.00. That's crazy.
Can you tell me where? With that glaring error I am really
interested in learning more. Google finds nothing with those
terms.
bill 
14 Sep
14 Sep
2:28 a.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
But can you still get a real PDP-11 replacement for
driving vintage hardware?
Probably not. But I think John Wilson of Ersatz-11 fame created a Unibus (or QBus?)
interface for PCs so E-11 could drive real DEC peripherals.
Given suitable transceivers, it would not be all that hard to create a PDP-11 replacement
with Unibus and/or Qbus capability out of an FPGA. There are working PDP11 emulations for
FPGAs.
Paul
I picked up a PC of a retired "DEC solutions" engineer.
He worked with the licensed Ersatz-11 of John Wilson.
In one of the PCs is that famous card to connect PDP-11 peripherals to a PC.
That card is not supported in the free version of Ersatz-11.
I have not yet looked at that PC, so I do not know whether it is QBUS or UNIBUS.
One of these days ...
Henk, PA8PDP
7:10 a.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On Sat, Sep 13, 2025 at 12:07 PM ben via cctalk <cctalk(a)classiccmp.org> wrote:
But can you still get a real PDP-11 replacement for
driving vintage
hardware?
Strobe Data is almost still around, but I think whoever's left may
just be in limited best-effort support mode for their remaining
customers. Osprey cards turn up occasionally and I *think* some may
have had luck getting licenses from them.
http://www.strobedata.com/home/products.html
3:39 p.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On Sep 13, 2025, at 12:59 PM, ben via cctalk
<cctalk(a)classiccmp.org> wrote:
On 2025-09-13 10:35 a.m., Milo Velimirović via cctalk wrote:
But can you still get a real PDP-11 replacement for driving vintage hardware?
Real pdp11s are somewhat scarce, but . . .
If you’ve got pdp11 UNIBUS or Q-Bus devices/controllers AND a backplane to plug them into,
but no pdp11 CPU, then a Unibone or Qbone is the thing you want. It will be as much (or as
little) of a CPU as you want.
On Sep
13, 2025, at 10:49 AM, Bill Gunshannon via cctalk <cctalk(a)classiccmp.org> wrote:
On 9/11/2025 4:30 PM, Jim Davis via cctalk wrote:
It has to be hyperbole.
No pdp11 ran 4.x, the best you can do is 2.11— which is still being patched and
maintained; see the pidp-11 mailing list. Probably not $3.00, but $30.00 will get you a
sytem on a DIP package that will emulate most anything. Spend a bit more for a Pi4 or Pi5
if you want to drive a PiDP-11. You can get an emulated 11/23 running 4.2 BSD for
$3.00. That's crazy.
Can you tell me where? With that glaring error I am really
interested in learning more. Google finds nothing with those
terms.
bill 
5:20 p.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On Sep 14, 2025, at 17:46, Milo Velimirović via cctalk
<cctalk(a)classiccmp.org> wrote:
The only cpu that the unibone and qbone emulate is a pdp-11/20 processor, (in addition to
several peripherals) last I knew. Nothing with memory management, for example. QBus
PDP-11 machines can be had (eBay has a couple, one looks like it probably has, one looks
like it probably has a power supply that needs work) and would be easier for most to deal
with as compared to most of the UNIBUS machines. Maybe you could sell John that old PDP
11 that I recall you obtaining from me decades ago. ;) of course it doesn’t have any
memory management either.
JRJ
On Sep 13, 2025, at 12:59 PM, ben via cctalk
<cctalk(a)classiccmp.org> wrote:
On 2025-09-13 10:35 a.m., Milo Velimirović via cctalk wrote:
But can you still get a real PDP-11 replacement for driving vintage hardware?
Real pdp11s are somewhat scarce, but . . .
If you’ve got pdp11 UNIBUS or Q-Bus devices/controllers AND a backplane to plug them
into, but no pdp11 CPU, then a Unibone or Qbone is the thing you want. It will be as much
(or as little) of a CPU as you want.
On Sep
13, 2025, at 10:49 AM, Bill Gunshannon via cctalk <cctalk(a)classiccmp.org> wrote:
> On 9/11/2025 4:30 PM, Jim Davis via cctalk wrote:
>> You can get an emulated 11/23 running 4.2 BSD for $3.00. That's crazy.
>
> Can you tell me where? With that glaring error I am really
> interested in learning more. Google finds nothing with those
> terms.
>
> bill
It has to be hyperbole.
No pdp11 ran 4.x, the best you can do is 2.11— which is still being patched and
maintained; see the pidp-11 mailing list. Probably not $3.00, but $30.00 will get you a
sytem on a DIP package that will emulate most anything. Spend a bit more for a Pi4 or Pi5
if you want to drive a PiDP-11.
11:51 p.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On 2025-09-14 6:20 p.m., Jay Jaeger via cctalk wrote:
> The only cpu that the unibone and qbone
emulate is a pdp-11/20 processor, (in addition to several peripherals) last I knew.
Nothing with memory management, for example. QBus PDP-11 machines can be had (eBay has a
couple, one looks like it probably has, one looks like it probably has a power supply that
needs work) and would be easier for most to deal with as compared to most of the UNIBUS
machines. Maybe you could sell John that old PDP 11 that I recall you obtaining from me
decades ago. ;) of course it doesn’t have any memory management either.
JRJ
Memory management does seem important as you get older. :)
Ben.
13 Sep
13 Sep
1:15 p.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On Sep 13, 2025, at 12:35 PM, Milo Velimirović via
cctalk <cctalk(a)classiccmp.org> wrote:
I would think a Raspberry Pico, which goes for $4, is enough of a processor to run SIMH.
Not a large config I suppose, and given that it's a bare metal system the port would
be a bit of work. But it seems doable.
paul
On Sep 13, 2025, at 10:49 AM, Bill Gunshannon via
cctalk <cctalk(a)classiccmp.org> wrote:
On 9/11/2025 4:30 PM, Jim Davis via cctalk wrote:
It has to be hyperbole.
No pdp11 ran 4.x, the best you can do is 2.11— which is still being patched and
maintained; see the pidp-11 mailing list. Probably not $3.00, but $30.00 will get you a
sytem on a DIP package that will emulate most anything. Spend a bit more for a Pi4 or Pi5
if you want to drive a PiDP-11. You can get an emulated 11/23 running 4.2 BSD for
$3.00. That's crazy.
Can you tell me where? With that glaring error I am really
interested in learning more. Google finds nothing with those
terms.
bill 
14 Sep
14 Sep
8:07 a.m.
New subject: [List] Re: Fun with PDP11 Assembly Language
On Sep 13, 2025, at 4:15 PM, Paul Koning via cctalk
<cctalk(a)classiccmp.org> wrote:
SIMH seems to be a bit heavyweight for a Pico, especially in the memory department. I’ve
been working on a standalone emulator for a while. An RP2040 is capable of running an
18-bit system with around 64KW of memory while an RP2350 is capable of running a full
18-bit system with 124KW. Using a “Maker Pi Pico” board from cytron.io
<http://cytron.io/> (an additional $10) to provide an SPI-based microSD drive, I’ve
been able to fun RSX-11M V4.5 and RSX-11D V6.2. Performance is not great but for ~$15, I
can’t complain.
John.
On Sep 13, 2025, at 12:35 PM, Milo Velimirović
via cctalk <cctalk(a)classiccmp.org> wrote:
I would think a Raspberry Pico, which goes for $4, is enough of a processor to run SIMH.
Not a large config I suppose, and given that it's a bare metal system the port would
be a bit of work. But it seems doable.
paul
On Sep 13, 2025, at 10:49 AM, Bill Gunshannon via
cctalk <cctalk(a)classiccmp.org> wrote:
On 9/11/2025 4:30 PM, Jim Davis via cctalk wrote:
It has to be hyperbole.
No pdp11 ran 4.x, the best you can do is 2.11— which is still being patched and
maintained; see the pidp-11 mailing list. Probably not $3.00, but $30.00 will get you a
sytem on a DIP package that will emulate most anything. Spend a bit more for a Pi4 or Pi5
if you want to drive a PiDP-11.
You can get an emulated 11/23 running 4.2 BSD for
$3.00. That's crazy.
Can you tell me where? With that glaring error I am really
interested in learning more. Google finds nothing with those
terms.
bill
2:08 p.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
Hi all lovers of classic computing. As a blind lover of yester-years computers I would
like to share some personal experiences. Starting in the late ‘70s and continuing well
into the early 21st century; us blind folks happily plugged along on any number of Atari,
Commodore, Apple, and Microsoft DOS machines. While we considered it magic at the time;
there really was no magic to it just some simple science. We used external speech
synthesizers with names like Arctic, Double-Talk, DEC Talk, Vortex just to name a few. The
most common, and arguably the best was the venerable DEC Talk Express (external) and its
internal cousin the DEC TALK PC.
https://www.youtube.com/watch?v=bPW2S4fZMJY
Here is the general theory:
https://www.listening.com/blog/speech-synthesis
But from the end user’s point they didn’t have to concern themselves with that. In the
case of the popular DECTalk Express the user merely needed to connect the DecTalk to a DB9
serial port on their computer and direct their screen reader software to it.
For blind lovers of vintage computing now the software screen readers are still around in
various Internet archives. Many have been released into the public domain for use free of
charge. An example of this is JAWS for DOS:
https://allinaccess.com/happ/
The challenge is that the supply of used external speech synthesizers has or soon will be
dried up. Unfortunately, as we get old and pass on many of these units get thrown out.
Consequently, the world of vintage computing for us blind folks is coming to a close. What
would once again, open up the world of vintage computing to us blind folks is a recreation
of an External DECTalk Express. The way I can imagine this is that a Linux software speech
synthesizer, like ESpeak, could be running on a Raspberry Pie. The Pie would have a USB to
serial connection installed to allow for connection to a DB9 serial port on the computer,
which is what the screen readers expect. So far all of that is off-the-shelf software and
hardware. What would have to be created is a software program that could be run on the Pie
that would listen for the text stream coming in from the serial port and then pass that
input along to the speech synthesizer which in turn could speak through the headphone jack
on the Pie.
This program would have to listen and respond to DECTalk control character strings. They
can be found at:
https://rmdir.de/~michael/DECtalk_Express/rongemma/volume.htm
And now for my plea for help. If there are any Linux/Pie developers that would like to
take on this project for the benefit of all blind vintage computing enthusiasts, I would
love to hear from you. I honestly don’t know what fair compensation would be but I am sure
some compensation could be involved. Even if the fine folks here don’t want to get
personally involved I would love to hear opinions on the feasibility of this project as
well as suggestions.
Thanks
Frank
twoheartsinthedark(a)hotmail.com
Estimated parts list:
Raspberry Pie
https://www.amazon.com/CanaKit-Raspberry-Starter-Kit-PRO/dp/B0CRSNCJ6Y/ref=…
Speak speech synthesizer for Linux
https://espeak.sourceforge.net/download.html
USB to DB9 serial:
https://www.amazon.com/Adapter-Chipset，DB9-Serial-Converter-Windows/dp/B075…
15 Sep
15 Sep
1:37 a.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
Do you think espeak is the most suitable, or just a convenient example ?
A friend's commercial product used a system from Lernout & Houspie but it's
also something the current AI craze does moderately well (most of the time,
anyway..), often using an online server.
There are several open source choices too, as well as espeak and those
fairly expensive commercial systems.
I have collected a couple of external synths - A Votrax and a later DECTalk
than the one in your link. I understand these are also in demand by
musicians for their characteristic sound. I don't know if that's another
market for your idea - I would have thought a DAW would provide a good
environment for a software synth but they seem to like the DECTalk.
On Mon, Sep 15, 2025 at 7:52 AM Frank Ventura via cctalk <
cctalk(a)classiccmp.org> wrote:
Hi all lovers of classic computing. As a blind lover
of yester-years
computers I would like to share some personal experiences. Starting in the
late ‘70s and continuing well into the early 21st century; us blind folks
happily plugged along on any number of Atari, Commodore, Apple, and
Microsoft DOS machines. While we considered it magic at the time; there
really was no magic to it just some simple science. We used external speech
synthesizers with names like Arctic, Double-Talk, DEC Talk, Vortex just to
name a few. The most common, and arguably the best was the venerable DEC
Talk Express (external) and its internal cousin the DEC TALK PC.
https://www.youtube.com/watch?v=bPW2S4fZMJY
Here is the general theory:
https://www.listening.com/blog/speech-synthesis
But from the end user’s point they didn’t have to concern themselves with
that. In the case of the popular DECTalk Express the user merely needed to
connect the DecTalk to a DB9 serial port on their computer and direct
their screen reader software to it.
For blind lovers of vintage computing now the software screen readers are
still around in various Internet archives. Many have been released into the
public domain for use free of charge. An example of this is JAWS for DOS:
https://allinaccess.com/happ/
The challenge is that the supply of used external speech synthesizers has
or soon will be dried up. Unfortunately, as we get old and pass on many of
these units get thrown out. Consequently, the world of vintage computing
for us blind folks is coming to a close. What would once again, open up the
world of vintage computing to us blind folks is a recreation of an External
DECTalk Express. The way I can imagine this is that a Linux software speech
synthesizer, like ESpeak, could be running on a Raspberry Pie. The Pie
would have a USB to serial connection installed to allow for connection to
a DB9 serial port on the computer, which is what the screen readers expect.
So far all of that is off-the-shelf software and hardware. What would have
to be created is a software program that could be run on the Pie that would
listen for the text stream coming in from the serial port and then pass
that input along to the speech synthesizer which in turn could speak
through the headphone jack on the Pie.
This program would have to listen and respond to DECTalk control character
strings. They can be found at:
https://rmdir.de/~michael/DECtalk_Express/rongemma/volume.htm
And now for my plea for help. If there are any Linux/Pie developers that
would like to take on this project for the benefit of all blind vintage
computing enthusiasts, I would love to hear from you. I honestly don’t know
what fair compensation would be but I am sure some compensation could be
involved. Even if the fine folks here don’t want to get personally involved
I would love to hear opinions on the feasibility of this project as well as
suggestions.
Thanks
Frank
twoheartsinthedark(a)hotmail.com
Estimated parts list:
Raspberry Pie
https://www.amazon.com/CanaKit-Raspberry-Starter-Kit-PRO/dp/B0CRSNCJ6Y/ref=…
Speak speech synthesizer for Linux
https://espeak.sourceforge.net/download.html
USB to DB9 serial:
https://www.amazon.com/Adapter-Chipset
，DB9-Serial-Converter-Windows/dp/B0759HSLP1/ref=sr_1_1_sspa?crid=236I64S61EQUS&dib=eyJ2IjoiMSJ9.xWQsG3VO7IqOId9P7LqGZq38EEH2QvMypF3SndBiNDHWvPNKkkfgYzYA0pD41q3IjI2_ArJV46Wj27eBeQcyBdbW13HiUK_p3b4D_w3wOl3jRSF0UykqtRxJP_l1OKBvCNnI8Gk2f0DaY-xt74-p4WlZ7lZONme6W9bu9qLr_u7-TCe6V3k47ERRnKr1p4STS93i_tAK0u2UP-TBvMkG5QysadotCwOMGo-U-L19WG0.PCwoBg8nZ8_4xUSozrwGK9opLdpTM5qNhfSRaBgtyJU&dib_tag=se&keywords=USB%2Bto%2Bdb9%2Bserial&qid=1757878593&sprefix=usb%2Bto%2Bdb9%2Bserial%2Caps%2C154&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1<
https://www.amazon.com/Adapter-Chipset%EF%BC%8CDB9-Serial-Converter-Windows…
2:16 a.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
Thanks for the reply. No, I merely threw ESpeak out there as an example. Any Linux speech
synthesizer would work. The only one synthesizer I wouldn’t recommend is, as you
mentioned, the online ones. That would make it dependent on an internet connection and not
as self-contained as I would imagine. Sadly, I no longer own a hardware synthesizer of my
own. I did have a working one but gave it to a friend who was in need of one. I have been
searching EBay, without luck, for another. That is interesting about musicians. I never
knew that. Well hopefully someone who is versed in this type of software development may
want to take up this project.
Frank
On Sep 15, 2025, at 4:37 AM, Adrian Godwin via cctalk
<cctalk(a)classiccmp.org> wrote:
Do you think espeak is the most suitable, or just a convenient example ?
A friend's commercial product used a system from Lernout & Houspie but it's
also something the current AI craze does moderately well (most of the time,
anyway..), often using an online server.
There are several open source choices too, as well as espeak and those
fairly expensive commercial systems.
I have collected a couple of external synths - A Votrax and a later DECTalk
than the one in your link. I understand these are also in demand by
musicians for their characteristic sound. I don't know if that's another
market for your idea - I would have thought a DAW would provide a good
environment for a software synth but they seem to like the DECTalk.
7:11 a.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
And now for my plea for help. If there are any
Linux/Pie developers that would like to take on this project for the benefit of all blind
vintage computing enthusiasts, I would love to hear from you. I honestly don’t know what
fair compensation would be but I am sure some compensation could be involved. Even if the
fine folks here don’t want to get personally involved I would love to hear opinions on the
feasibility of this project as well as suggestions.
What about simply using the DECtalk source code itself?
https://github.com/dectalk/dectalk
--
------------------------------------ personal: http://www.cameronkaiser.com/ --
Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser(a)floodgap.com
-- How are you gentlemen? All your base are belong to us! ---------------------
7:55 a.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
Excellent. I found an archive of useful versions at
https://dectalk.nu/Info.html but it's not clear without downloading if they
include any source.
I would expect scripting the connection of another synthesizer to a
serial input would be trivial, but processing the unspoken command (pitch
etc) would involve translation and reimplementation to convert DECTalk
syntax into espeak (or whatever). Actual DECTalk code would be much less
work.
On Mon, Sep 15, 2025 at 3:36 PM Cameron Kaiser via cctalk <
cctalk(a)classiccmp.org> wrote:
And now for my plea for help. If there are any
Linux/Pie developers that
would like to take on this project for the benefit of all blind vintage
computing enthusiasts, I would love to hear from you. I honestly don’t know
what fair compensation would be but I am sure some compensation could be
involved. Even if the fine folks here don’t want to get personally involved
I would love to hear opinions on the feasibility of this project as well as
suggestions.
What about simply using the DECtalk source code itself?
https://github.com/dectalk/dectalk
--
------------------------------------ personal:
http://www.cameronkaiser.com/ --
Cameron Kaiser * Floodgap Systems * www.floodgap.com *
ckaiser(a)floodgap.com
-- How are you gentlemen? All your base are belong to us!
---------------------
8:24 a.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
Ah nothing sounds like DECTalk like DECTalk 😉 That is a good idea. I am not versed in
Linux development so I have no idea what is involved with using that. I would assume it
would need at least one more component to be developed to accpt the serial port input,
respond to the control characters and pass the input to that DECTalk code.
-----Original Message-----
From: Cameron Kaiser via cctalk <cctalk(a)classiccmp.org>
Sent: Monday, September 15, 2025 10:11 AM
To: Frank Ventura via cctalk <cctalk(a)classiccmp.org>
Cc: Cameron Kaiser <spectre(a)floodgap.com>
Subject: [cctalk] Re: Does anyone know of anyone who may want to help out blind vintage
computing enthusiasts
And now for my plea for help. If there are any
Linux/Pie developers that would like to take on this project for the benefit of all blind
vintage computing enthusiasts, I would love to hear from you. I honestly don’t know what
fair compensation would be but I am sure some compensation could be involved. Even if the
fine folks here don’t want to get personally involved I would love to hear opinions on the
feasibility of this project as well as suggestions.
What about simply using the DECtalk source code itself?
https://github.com/dectalk/dectalk
--
------------------------------------ personal: http://www.cameronkaiser.com/ --
Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser(a)floodgap.com
-- How are you gentlemen? All your base are belong to us! ---------------------
16 Sep
16 Sep
11:14 a.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
On Monday (09/15/2025 at 03:24PM +0000), Frank Ventura via cctalk wrote:
Ah nothing sounds like DECTalk like DECTalk 😉 That is
a good idea. I am not versed in Linux development so I have no idea what is involved with
using that. I would assume it would need at least one more component to be developed to
accpt the serial port input, respond to the control characters and pass the input to that
DECTalk code.
I tried to reply to this but for some reason my reply was rejected by
the moderator.
The moderator gave the following reason for rejecting your request:
"[No reason given]"
Anyway, I hoped to suggest that maybe Joe Grand could be convinced to
produce his EMIC2 speech synthesizer module again as it is a fully
DECTALK compatible module with serial interface. If you need USB,
you'd just frontend it with a USB to serial adapter,
https://grandideastudio.com/portfolio/do-it-yourself/emic-2-text-to-speech/
They used to be sold by SparkFun but they stopped producing them in 2023.
Chris
--
Chris Elmquist
17 Sep
17 Sep
8:21 a.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
Epson still makes a DECTalk chip, basically DECTalk code on an Epson MCU
with a serial interface: S1V30120.
https://www.mikroe.com/text-to-speech-click
I really hope someone ports DECTalk to an STM32 with a DAC...
--
Anders Nelson
On Wed, Sep 17, 2025, 10:56 AM Chris Elmquist via cctalk <
cctalk(a)classiccmp.org> wrote:
On Monday (09/15/2025 at 03:24PM +0000), Frank Ventura
via cctalk wrote:
Ah nothing sounds like DECTalk like DECTalk 😉
That is a good idea. I am
not versed in Linux development so I have no idea what is involved with
using that. I would assume it would need at least one more component to be
developed to accpt the serial port input, respond to the control characters
and pass the input to that DECTalk code.
I tried to reply to this but for some reason my reply was rejected by
the moderator.
The moderator gave the following reason for rejecting your request:
"[No reason given]"
Anyway, I hoped to suggest that maybe Joe Grand could be convinced to
produce his EMIC2 speech synthesizer module again as it is a fully
DECTALK compatible module with serial interface. If you need USB,
you'd just frontend it with a USB to serial adapter,
https://grandideastudio.com/portfolio/do-it-yourself/emic-2-text-to-speech/
They used to be sold by SparkFun but they stopped producing them in 2023.
Chris
--
Chris Elmquist
8:31 a.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
On Wednesday (09/17/2025 at 11:21AM -0400), Anders Nelson wrote:
Epson still makes a DECTalk chip, basically DECTalk
code on an Epson MCU
with a serial interface: S1V30120.
Yup! That's the part on Joe Grand's board-- front-ended by a
Coldfire MCU of some sort.
https://www.mikroe.com/text-to-speech-click
I really hope someone ports DECTalk to an STM32 with a DAC...
That would be a nice modernization.
Chris
On Wed, Sep 17, 2025, 10:56 AM Chris Elmquist via
cctalk <
cctalk(a)classiccmp.org> wrote:
> On Monday (09/15/2025 at 03:24PM +0000), Frank Ventura via cctalk wrote:
> > Ah nothing sounds like DECTalk like DECTalk 😉 That is a good idea. I am
> not versed in Linux development so I have no idea what is involved with
> using that. I would assume it would need at least one more component to be
> developed to accpt the serial port input, respond to the control characters
> and pass the input to that DECTalk code.
>
> I tried to reply to this but for some reason my reply was rejected by
> the moderator.
>
> The moderator gave the following reason for rejecting your request:
>
> "[No reason given]"
>
> Anyway, I hoped to suggest that maybe Joe Grand could be convinced to
> produce his EMIC2 speech synthesizer module again as it is a fully
> DECTALK compatible module with serial interface. If you need USB,
> you'd just frontend it with a USB to serial adapter,
>
> https://grandideastudio.com/portfolio/do-it-yourself/emic-2-text-to-speech/
>
> They used to be sold by SparkFun but they stopped producing them in 2023.
>
> Chris
--
Chris Elmquist
9:58 a.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
On Sep 17, 2025, at 11:21 AM, Anders Nelson via cctalk
<cctalk(a)classiccmp.org> wrote:
Epson still makes a DECTalk chip, basically DECTalk code on an Epson MCU
with a serial interface: S1V30120.
https://www.mikroe.com/text-to-speech-click
I really hope someone ports DECTalk to an STM32 with a DAC...
Or a Pico, which could do it without a DAC, using the PIO as a PWM analog output driver.
paul
10:23 a.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
I'm looking at running the dectalk code from github on a pi zero, which
seems a convenient way to avoid any proprietary parts. Initial test on a
desktop machine was easy to builds and worked out of the box.
However, I'm dreadful for getting bogged down in distractions and I don't
know whether good compatibilty will require a lot of work on the serial
interface (I anticipate possible problems with text buffering and
bidirectional data as with responses to commands). The Emic2 in particular
looks to have included significant work there.
I'd strongly encourage Frank or anyone else to look further into those
options (which all sound good) regardless of whether I get anywhere.
On Wed, Sep 17, 2025 at 6:07 PM Paul Koning via cctalk <
cctalk(a)classiccmp.org> wrote:
On Sep 17, 2025, at 11:21 AM, Anders Nelson via
cctalk <
cctalk(a)classiccmp.org> wrote:
Epson still makes a DECTalk chip, basically DECTalk code on an Epson MCU
with a serial interface: S1V30120.
https://www.mikroe.com/text-to-speech-click
I really hope someone ports DECTalk to an STM32 with a DAC...
Or a Pico, which could do it without a DAC, using the PIO as a PWM analog
output driver.
paul
10:45 a.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
On Sep 17, 2025, at 11:21 AM, Anders Nelson via cctalk
<cctalk(a)classiccmp.org> wrote:
Epson still makes a DECTalk chip, basically DECTalk code on an Epson MCU
with a serial interface: S1V30120.
https://www.mikroe.com/text-to-speech-click
That's rather expensive. It's also curious that German and French are not
supported, though they are included in the version on Github.
paul
12:57 p.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
I presume Parallax stopped building the EMIC2 board through lack of demand.
The components seem to be still available and relatively cheap (about $12
on Mouser for each of the two large chips). The project page includes all
the pcb details but I don't see source or even binary.
A quick test of the github code uses about 8% CPU on a Pi 4 so should be
within range of a Pi 0. The Pi 0 has no audio out and USB is probably the
cheapest way to do it. The built-in (PWM) audio on the Pi4 is dreadfully
noisy so no real loss and alternative audio modules relatively expensive.
You'd soon get to the $55 of the mikroe.
Might be in range of an ESP32, though the big advantage of a Pi is the
extraordinarily good range of support - all the facilities of Linux without
having to write even a monitor.
On Wed, Sep 17, 2025 at 7:07 PM Paul Koning via cctalk <
cctalk(a)classiccmp.org> wrote:
On Sep 17, 2025, at 11:21 AM, Anders Nelson via
cctalk <
cctalk(a)classiccmp.org> wrote:
Epson still makes a DECTalk chip, basically DECTalk code on an Epson MCU
with a serial interface: S1V30120.
https://www.mikroe.com/text-to-speech-click
That's rather expensive. It's also curious that German and French are not
supported, though they are included in the version on Github.
paul
1:12 p.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
On Sep 17, 2025, at 3:57 PM, Adrian Godwin via cctalk
<cctalk(a)classiccmp.org> wrote:
I presume Parallax stopped building the EMIC2 board through lack of demand.
The components seem to be still available and relatively cheap (about $12
on Mouser for each of the two large chips). The project page includes all
the pcb details but I don't see source or even binary.
A quick test of the github code uses about 8% CPU on a Pi 4 so should be
within range of a Pi 0. The Pi 0 has no audio out and USB is probably the
cheapest way to do it. The built-in (PWM) audio on the Pi4 is dreadfully
noisy so no real loss and alternative audio modules relatively expensive.
You'd soon get to the $55 of the mikroe.
Might be in range of an ESP32, though the big advantage of a Pi is the
extraordinarily good range of support - all the facilities of Linux without
having to write even a monitor.
Note that I said "Pico" which while also a Raspberry product has next to nothing
in common with a Pi, doesn't run Linux, and is far cheaper.
Re audio: I think simple audio DACs are quite cheap, but they have odd interface schemes
(steady bit streams). No trouble at all for the PIO engine in the Pico, though. I was
thinking at one time about using one of those when I needed a control voltage for a VCXO,
but for that the PWM is adequate. Direct PWM audio might also work ok with the PIO since
it could easily do 20 MHz clock rate so for, say, 11 kHz audio that's about 11
significant bits.
paul
1:31 p.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
Yes, I realised you suggested the Pico.
Since the github code is aimed at linuxes I initially stayed with that, but
the Pico is in the same class as the esp32 and likely could do it too.
However, I don't know whether the github code uses any threads or other
Unix features. It's less trivial to evaluate on linux than a no-OS
platform. Might be worth looking at Zephyr.
On Wed, Sep 17, 2025 at 9:13 PM Paul Koning <paulkoning(a)comcast.net> wrote:
On Sep 17, 2025, at 3:57 PM, Adrian Godwin via
cctalk <
cctalk(a)classiccmp.org> wrote:
I presume Parallax stopped building the EMIC2 board through lack of
demand.
The components seem to be still available and
relatively cheap (about $12
on Mouser for each of the two large chips). The project page includes all
the pcb details but I don't see source or even binary.
A quick test of the github code uses about 8% CPU on a Pi 4 so should be
within range of a Pi 0. The Pi 0 has no audio out and USB is probably
the
cheapest way to do it. The built-in (PWM) audio
on the Pi4 is dreadfully
noisy so no real loss and alternative audio modules relatively expensive.
You'd soon get to the $55 of the mikroe.
Might be in range of an ESP32, though the big advantage of a Pi is the
extraordinarily good range of support - all the facilities of Linux
without
having to write even a monitor.
Note that I said "Pico" which while also a Raspberry product has next to
nothing in common with a Pi, doesn't run Linux, and is far cheaper.
Re audio: I think simple audio DACs are quite cheap, but they have odd
interface schemes (steady bit streams). No trouble at all for the PIO
engine in the Pico, though. I was thinking at one time about using one of
those when I needed a control voltage for a VCXO, but for that the PWM is
adequate. Direct PWM audio might also work ok with the PIO since it could
easily do 20 MHz clock rate so for, say, 11 kHz audio that's about 11
significant bits.
paul
19 Sep
19 Sep
4:28 a.m.
New subject: Does anyone know of anyone who may want to help out blind vintage computing enthusiasts
On Sep 16, 2025, at 2:14 PM, Chris Elmquist
<chrise(a)pobox.com> wrote:
On Monday (09/15/2025 at 03:24PM +0000), Frank Ventura via cctalk wrote:
Chris, the fact that it was discontinued may explain the short supply and high prices on
EBay for hardware synthesizers.
Thanks
Frank
Ah nothing sounds like DECTalk like DECTalk 😉
That is a good idea. I am not versed in Linux development so I have no idea what is
involved with using that. I would assume it would need at least one more component to be
developed to accpt the serial port input, respond to the control characters and pass the
input to that DECTalk code.
I tried to reply to this but for some reason my reply was rejected by
the moderator.
The moderator gave the following reason for rejecting your request:
"[No reason given]"
Anyway, I hoped to suggest that maybe Joe Grand could be convinced to
produce his EMIC2 speech synthesizer module again as it is a fully
DECTALK compatible module with serial interface. If you need USB,
you'd just frontend it with a USB to serial adapter,
https://grandideastudio.com/portfolio/do-it-yourself/emic-2-text-to-speech/
They used to be sold by SparkFun but they stopped producing them in 2023.
Chris
--
Chris Elmquist
10 Sep
10 Sep
12:10 p.m.
On 9/10/25 11:02, ben via cctalk wrote:
On 2025-09-10 8:46 a.m., Jon Elson via cctalk wrote:
Oh, absolutely, the PDP-11 was the best 16-bit instruction
set I've ever seen, and I've seen quite a few. But, there
were substantial limitations. Then, I moved up to the VAX,
which was a real experience! Over the top instruction set,
but it kept all the greatness of the PDP-11, and solved the
address space issue.
Jon
On 9/10/25 08:32, Paul Koning via cctalk wrote:
But even then you could see the hand writing on the wall
for 16 bits. > On Sep 9, 2025, at 8:52 PM, Martin Eberhard
via cctalk
> <cctalk(a)classiccmp.org> wrote:
>
> I just love the PDP11's assembly language.
Yes, the PDP-11 machine language was INCREDIBLY
brilliant, and did the very best with what you could do
in 16 bits!
12:25 p.m.
On Sep 10, 2025, at 3:10 PM, Jon Elson via cctalk
<cctalk(a)classiccmp.org> wrote:
On 9/10/25 11:02, ben via cctalk wrote:
For a while, until programmers used it all up. This is the Microsoft effect: programs
will expand to consume all available CPU, memory, and storage.
paul
On 2025-09-10 8:46 a.m., Jon Elson via cctalk
wrote:
Oh, absolutely, the PDP-11 was the best 16-bit instruction set I've ever seen, and
I've seen quite a few. But, there were substantial limitations. Then, I moved up to
the VAX, which was a real experience! Over the top instruction set, but it kept all the
greatness of the PDP-11, and solved the address space issue. On 9/10/25 08:32, Paul Koning via cctalk wrote:
But even then you could see the hand writing on the wall for 16 bits. > On Sep 9, 2025, at 8:52 PM, Martin Eberhard
via cctalk <cctalk(a)classiccmp.org> wrote:
>
> I just love the PDP11's assembly language.
Yes, the PDP-11 machine language was INCREDIBLY brilliant, and did the very best with
what you could do in 16 bits!
1:18 p.m.
You’re a hardware guy, huh?
Sent from my iPhone
On Sep 10, 2025, at 12:31, Paul Koning via cctalk
<cctalk(a)classiccmp.org> wrote:
On Sep 10, 2025, at 3:10 PM, Jon Elson via cctalk
<cctalk(a)classiccmp.org> wrote:
For a while, until programmers used it all up. This is the Microsoft effect: programs
will expand to consume all available CPU, memory, and storage.
paul
On 9/10/25 11:02, ben via cctalk wrote:
On 2025-09-10 8:46 a.m., Jon Elson via cctalk wrote:
Oh, absolutely, the PDP-11 was the best 16-bit instruction set I've ever seen, and
I've seen quite a few. But, there were substantial limitations. Then, I moved up to
the VAX, which was a real experience! Over the top instruction set, but it kept all the
greatness of the PDP-11, and solved the address space issue.
On 9/10/25 08:32, Paul Koning via cctalk wrote:
>> On Sep 9, 2025, at 8:52 PM, Martin Eberhard via cctalk
<cctalk(a)classiccmp.org> wrote:
>>
>> I just love the PDP11's assembly language.
Yes, the PDP-11 machine language was INCREDIBLY brilliant, and did the very best with
what you could do in 16 bits!
But even then you could see the hand writing on the wall for 16 bits.
1:25 p.m.
Nope. But I learned programming back when machine memories were measured in k words --
like the college timesharing 11/20 with 28kW, or the physics department lab 11/20 with 8
kW (and an RC11 hard drive, 64 kW if I remember right). For that matter, I remember
squeezing CDC 6400 boot code into a 12 word "deadstart panel" and the secondary
boot into a 320 word disk sector.
Nowadays some of the machines I work with have a terabyte of RAM. Mindboggling.
paul
On Sep 10, 2025, at 4:18 PM, Wayne S
<wayne.sudol(a)hotmail.com> wrote:
You’re a hardware guy, huh?
Sent from my iPhone
> On Sep 10, 2025, at 12:31, Paul Koning via cctalk <cctalk(a)classiccmp.org>
wrote:
>
>
>
>> On Sep 10, 2025, at 3:10 PM, Jon Elson via cctalk <cctalk(a)classiccmp.org>
wrote:
>>
>>> On 9/10/25 11:02, ben via cctalk wrote:
>>> On 2025-09-10 8:46 a.m., Jon Elson via cctalk wrote:
>>>> On 9/10/25 08:32, Paul Koning via cctalk wrote:
>>>>>> On Sep 9, 2025, at 8:52 PM, Martin Eberhard via cctalk
<cctalk(a)classiccmp.org> wrote:
>>>>>>
>>>>>> I just love the PDP11's assembly language.
>>>>
>>>> Yes, the PDP-11 machine language was INCREDIBLY brilliant, and did the
very best with what you could do in 16 bits!
>>>
>>> But even then you could see the hand writing on the wall for 16 bits.
>>
>> Oh, absolutely, the PDP-11 was the best 16-bit instruction set I've ever
seen, and I've seen quite a few. But, there were substantial limitations. Then, I
moved up to the VAX, which was a real experience! Over the top instruction set, but it
kept all the greatness of the PDP-11, and solved the address space issue.
>
> For a while, until programmers used it all up. This is the Microsoft effect:
programs will expand to consume all available CPU, memory, and storage.
>
> paul
>
7:37 p.m.
On 2025-09-10 2:25 p.m., Paul Koning via cctalk wrote:
Nope. But I learned programming back when machine
memories were measured in k words -- like the college timesharing 11/20 with 28kW, or the
physics department lab 11/20 with 8 kW (and an RC11 hard drive, 64 kW if I remember
right). For that matter, I remember squeezing CDC 6400 boot code into a 12 word
"deadstart panel" and the secondary boot into a 320 word disk sector.
Nowadays some of the machines I work with have a terabyte of RAM. Mindboggling.
I find it more mind boggling that it runs with out memory errors.
paul
Ben.
9:18 a.m.
I was able to get over my PDP-11 depression after programming 6502's and
Z80's for 10 years.
I finally worked on the 68K in the late 80's, It felt like an old shoe.
On Wed, Sep 10, 2025 at 8:11 AM Jon Elson via cctalk <cctalk(a)classiccmp.org>
wrote:
On 9/10/25 08:32, Paul Koning via cctalk wrote:
> On Sep 9, 2025, at 8:52 PM, Martin Eberhard
via cctalk <
cctalk(a)classiccmp.org> wrote:
>
> I just love the PDP11's assembly language.
Yes, the PDP-11 machine language was INCREDIBLY brilliant,
and did the very best with what you could do in 16 bits!
Jon
7:51 p.m.
when the PDP 11 first came out, that was the first time I wanted a computer
for myself at home, the earlier ones that I knew of had too cockeyed and
limited instruction sets, after my programming experience being on
mainframes with CISC instructions. I actually thought about how much
sacrifice it would take to buy one.
--
--Carey
On 9/10/25 08:32, Paul Koning via cctalk wrote:
> On Sep 9, 2025, at 8:52 PM, Martin Eberhard
via cctalk <
cctalk(a)classiccmp.org> wrote:
>
> I just love the PDP11's assembly language.
Yes, the PDP-11 machine language was INCREDIBLY brilliant,
and did the very best with what you could do in 16 bits!
Jon
10:30 p.m.
On 2025-09-10 8:51 p.m., Carey Schug via cctalk wrote:
when the PDP 11 first came out, that was the first
time I wanted a computer
for myself at home, the earlier ones that I knew of had too cockeyed and
limited instruction sets, after my programming experience being on
mainframes with CISC instructions. I actually thought about how much
sacrifice it would take to buy one.
You still have cocky and limited instruction sets,
but $1.99 will get you a 16 bit chip micro controller in quantities of one.
I drooled at the Heath-kit H-11 when it came out,but when I had money
it was gone.
I just picked up a cheap Laser cutter/engraver and you have a tiny hand
sized usb box controlling it. To think, it was not that long ago it took
a whole rack box to do the the same thing.
Ben.
17
days inactive
26
days old
49 comments
19 participants
participants (19)
-
Adrian Godwin -
Anders Nelson -
ben -
Bill Gunshannon -
Cameron Kaiser -
Carey Schug -
Chris Elmquist -
Frank Leonhardt -
Frank Ventura -
Gavin Scott -
Henk Gooijen -
Jay Jaeger -
Jim Davis -
johnforecast＠comcast.net -
Jon Elson -
Martin Eberhard -
Milo Velimirović -
Paul Koning -
Wayne S