5 ms·

NitrOS-9, Unix-like operating system for the 6809

88 points by bilegeek 5y ago

cagey 5y ago
Byte Magazine ran a 2-part article on the design of the 6809 http://tlindner.macmess.org/wp-content/uploads/2006/09/Byte_6809_Articles.pdf http://tlindner.macmess.org/wp-content/uploads/2006/09/Byte_...
ursusarcanum 5y ago
The original of this Microware OS-9 was my first exposure to a "unix like" operating system in the 80s. It was pretty amazing that a mutli-user, multitasking operating system kernel can fit in 8k.
- hashmash 5y ago
  Even more amazing is that OS-9 was available for the "toy" Color Computer 15 years before multitasking became available for Windows or MacOS. The only thing preventing the CoCo from supporting safe multi-user interaction is an MMU that restricted higher address ranges. This would make it impossible to change the interrupt handlers, although interrupts could still be masked. The 6809 NMI feature (non-maskable interrupt) when combined with the MMU could then be used to jump back into kernel mode.
  - skissane 5y ago
    > The only thing preventing the CoCo from supporting safe multi-user interaction is an MMU that restricted higher address ranges I don't think that would have stopped people from actively using it as a multi-user system in its heyday. I think other systems used for multi-user computing at the same time often had similar security deficits (examples: MP/M, PICK, MUMPS, Alpha Microsystems AMOS) Standards and expectations were a lot lower back then, and much greater reliance was placed on trusting users, and the obscurity of whatever security holes existed
  - jjav 5y ago
    > Even more amazing is that OS-9 was available for the "toy" Color Computer 15 years before multitasking became available for Windows or MacOS. Indeed. OS-9 on the CoCo is what I grew up on and it spoiled me for all mainstream systems later when I realized how inferior they were to what I got used to as a kid. Multi-tasking multi-user OS on an 8 bit 6809 with 128K of RAM (and a price of just a few hundred dollars, back when an IBM PC was thousands). It also made me feel very familiar when I first encountered various UNIX systems so the transition was easy.
    - canadian_tired 5y ago
      You and me both. I ran OS-9 on my CoCo 1 in 64Kb RAM... sometime in '84 - '85. Could not do a lot, but it gave me a bit of grounding when I was dropped into SCO Unix in the late 80's.
      - jjav 5y ago
        Oh right, there was OS-9 Level I which ran on the CoCo 1 and 2, but with the max of 64K it was fairly limited in practice, although still a great learning platform. Later there was OS-9 Level II on the CoCo3 which was much more usable as a daily driver OS.
mikewarot 5y ago
I've only really heard legends about OS-9. The fact that you could support two users in real time with neither one slowing down on a machine with a bit-banged serial port and a single sided floppy disk set the bar of performance I expect from a processor far too high for decades.
- lproven 5y ago
  It isn't exactly a secret. :-) https://en.wikipedia.org/wiki/OS-9 https://en.wikipedia.org/wiki/OS-9
- PaulHoule 5y ago
  I had a Coco 3 with both a bit-banging serial port and a UART. One was connected to a DEC Correspondent printing terminal https://en.wikipedia.org/wiki/DECwriter#DECwriter_Correspondent https://en.wikipedia.org/wiki/DECwriter#DECwriter_Correspond... and other into a TRS-80 Model 100 https://en.wikipedia.org/wiki/TRS-80_Model_100 https://en.wikipedia.org/wiki/TRS-80_Model_100 I could log into those two terminals and into the main console (keyboard and screen) at the same time.
protomyth 5y ago
The 6809 is a fun processor to program in assembly and still my favorite 8-bit chip. The 8086/88 was such a let down after it. It would be interesting to have a 64-bit version just to play with for projects.
- ddingus 5y ago
  My favorite too. A 64 bit, or even 32 bit one, with 64 bit available like 16 bit is available on the 8 bit chip, would be great fun!
- jjav 5y ago
  > The 6809 is a fun processor to program in assembly and still my favorite 8-bit chip. The 8086/88 was such a let down after it. Yes! I learned assembly on thge 6809 and had a hard time believing what a step down the 8086 was a few years later when I encountered it.
  - PaulHoule 5y ago
    The 6809 is the one chip I've coded for which has fewer registers than the 8086! I liked 6809 assembly (easy to write position independent code, Motorola had found religion in ROMable libraries) but I liked 8086 assembly to. In a high-level language you were forced to pick a 'tiny', 'small', 'medium', 'large' memory model based on how much code and data you had. In assembly you could do clever things with the segmentation registers (copy from one segment to another, using the same index register for the source and destinations)
- zabzonk 5y ago
  It was sexy, for an 8-bit CPU, not least because it had a SEX instruction!
  - crest 5y ago
    So did the CDP1802.
  - ansible 5y ago
ddingus 5y ago
I believe this OS can take advantage of a 6309, if one is equipped.
edgyquant 5y ago
Looks like it’s been hugged to death, I’m getting an internal server error (can not access db)
dboreham 5y ago
The first few computers I built were 6909-based and ran OS-9. I implemented a ram disk driver, and a "rom disk" using bank selection to allow > 64k capacity, since at the time I worked for a company that had large quantities of memory chips in the lab :) Good times.
rwmj 5y ago
Reading between the lines, this is derived from OS-9 and so not fully open source?
- lproven 5y ago
  That is my impression. Microware is still around and selling OS-9: https://www.microware.com/ https://www.microware.com/
jll29 5y ago
Here's a video if you'd like to see how its windows look like: https://www.youtube.com/watch?v=JU8SIC-4Smw https://www.youtube.com/watch?v=JU8SIC-4Smw
tyingq 5y ago
In somewhat the same space, there's FUZIX[1], which supports the Z80, 68k, and 6809. Also, recently, someone ported it for the Raspberry PI pico, which makes it easy to get it up and running with something modern: https://cowlark.com/2021-02-16-fuzix-pi-pico/ https://cowlark.com/2021-02-16-fuzix-pi-pico/ Edit: Also ported to the 8266: https://cowlark.com/2021-02-09-esp8266-fuzix/ https://cowlark.com/2021-02-09-esp8266-fuzix/ [1] http://www.fuzix.org/ http://www.fuzix.org/

88 points by bilegeek 5y ago

Byte Magazine ran a 2-part article on the design of the 6809 http://tlindner.macmess.org/wp-content/uploads/2006/09/Byte_6809_Articles.pdf http://tlindner.macmess.org/wp-content/uploads/2006/09/Byte_...

ursusarcanum 5y ago

The original of this Microware OS-9 was my first exposure to a "unix like" operating system in the 80s. It was pretty amazing that a mutli-user, multitasking operating system kernel can fit in 8k.

hashmash 5y ago
Even more amazing is that OS-9 was available for the "toy" Color Computer 15 years before multitasking became available for Windows or MacOS. The only thing preventing the CoCo from supporting safe multi-user interaction is an MMU that restricted higher address ranges. This would make it impossible to change the interrupt handlers, although interrupts could still be masked. The 6809 NMI feature (non-maskable interrupt) when combined with the MMU could then be used to jump back into kernel mode.
- skissane 5y ago
  > The only thing preventing the CoCo from supporting safe multi-user interaction is an MMU that restricted higher address ranges I don't think that would have stopped people from actively using it as a multi-user system in its heyday. I think other systems used for multi-user computing at the same time often had similar security deficits (examples: MP/M, PICK, MUMPS, Alpha Microsystems AMOS) Standards and expectations were a lot lower back then, and much greater reliance was placed on trusting users, and the obscurity of whatever security holes existed
- jjav 5y ago
  > Even more amazing is that OS-9 was available for the "toy" Color Computer 15 years before multitasking became available for Windows or MacOS. Indeed. OS-9 on the CoCo is what I grew up on and it spoiled me for all mainstream systems later when I realized how inferior they were to what I got used to as a kid. Multi-tasking multi-user OS on an 8 bit 6809 with 128K of RAM (and a price of just a few hundred dollars, back when an IBM PC was thousands). It also made me feel very familiar when I first encountered various UNIX systems so the transition was easy.
  - canadian_tired 5y ago
    You and me both. I ran OS-9 on my CoCo 1 in 64Kb RAM... sometime in '84 - '85. Could not do a lot, but it gave me a bit of grounding when I was dropped into SCO Unix in the late 80's.
    - jjav 5y ago
      Oh right, there was OS-9 Level I which ran on the CoCo 1 and 2, but with the max of 64K it was fairly limited in practice, although still a great learning platform. Later there was OS-9 Level II on the CoCo3 which was much more usable as a daily driver OS.

mikewarot 5y ago

I've only really heard legends about OS-9. The fact that you could support two users in real time with neither one slowing down on a machine with a bit-banged serial port and a single sided floppy disk set the bar of performance I expect from a processor far too high for decades.

lproven 5y ago
It isn't exactly a secret. :-) https://en.wikipedia.org/wiki/OS-9 https://en.wikipedia.org/wiki/OS-9
PaulHoule 5y ago
I had a Coco 3 with both a bit-banging serial port and a UART. One was connected to a DEC Correspondent printing terminal https://en.wikipedia.org/wiki/DECwriter#DECwriter_Correspondent https://en.wikipedia.org/wiki/DECwriter#DECwriter_Correspond... and other into a TRS-80 Model 100 https://en.wikipedia.org/wiki/TRS-80_Model_100 https://en.wikipedia.org/wiki/TRS-80_Model_100 I could log into those two terminals and into the main console (keyboard and screen) at the same time.

protomyth 5y ago

The 6809 is a fun processor to program in assembly and still my favorite 8-bit chip. The 8086/88 was such a let down after it. It would be interesting to have a 64-bit version just to play with for projects.

ddingus 5y ago
My favorite too. A 64 bit, or even 32 bit one, with 64 bit available like 16 bit is available on the 8 bit chip, would be great fun!
jjav 5y ago
> The 6809 is a fun processor to program in assembly and still my favorite 8-bit chip. The 8086/88 was such a let down after it. Yes! I learned assembly on thge 6809 and had a hard time believing what a step down the 8086 was a few years later when I encountered it.
- PaulHoule 5y ago
  The 6809 is the one chip I've coded for which has fewer registers than the 8086! I liked 6809 assembly (easy to write position independent code, Motorola had found religion in ROMable libraries) but I liked 8086 assembly to. In a high-level language you were forced to pick a 'tiny', 'small', 'medium', 'large' memory model based on how much code and data you had. In assembly you could do clever things with the segmentation registers (copy from one segment to another, using the same index register for the source and destinations)
zabzonk 5y ago
It was sexy, for an 8-bit CPU, not least because it had a SEX instruction!
- crest 5y ago
  So did the CDP1802.
- ansible 5y ago

ddingus 5y ago

I believe this OS can take advantage of a 6309, if one is equipped.

edgyquant 5y ago

Looks like it’s been hugged to death, I’m getting an internal server error (can not access db)

dboreham 5y ago

The first few computers I built were 6909-based and ran OS-9. I implemented a ram disk driver, and a "rom disk" using bank selection to allow > 64k capacity, since at the time I worked for a company that had large quantities of memory chips in the lab :) Good times.

rwmj 5y ago

Reading between the lines, this is derived from OS-9 and so not fully open source?

lproven 5y ago
That is my impression. Microware is still around and selling OS-9: https://www.microware.com/ https://www.microware.com/

jll29 5y ago

Here's a video if you'd like to see how its windows look like: https://www.youtube.com/watch?v=JU8SIC-4Smw https://www.youtube.com/watch?v=JU8SIC-4Smw

tyingq 5y ago

In somewhat the same space, there's FUZIX[1], which supports the Z80, 68k, and 6809. Also, recently, someone ported it for the Raspberry PI pico, which makes it easy to get it up and running with something modern: https://cowlark.com/2021-02-16-fuzix-pi-pico/ https://cowlark.com/2021-02-16-fuzix-pi-pico/ Edit: Also ported to the 8266: https://cowlark.com/2021-02-09-esp8266-fuzix/ https://cowlark.com/2021-02-09-esp8266-fuzix/ [1] http://www.fuzix.org/ http://www.fuzix.org/