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The blog posts have a ton more detail and make for fascinating reading (or browsing the pictures): https://dekunukem.wordpress.com/ https://dekunukem.wordpress

The blog posts have a ton more detail and make for fascinating reading (or browsing the pictures): https://dekunukem.wordpress.com/ https://dekunukem.wordpress.com/ It's an interesting take on retro; gives the user the feel of a retro computer without all the gnarly period-accurate hardware. Also amusing that the STM32 supporting CPU has far more power than the main Z80 CPU.

throwawayish 10y ago
> Also amusing that the STM32 supporting CPU has far more power than the main Z80 CPU. I believe some Commodore drive already had two processors identical to the main processor of the computer -- effectively giving the drive more processing power than the actual computer :)
- ChuckMcM 10y ago
  One of the fun things on my Z80 CP/M machine was a 20MB Seagate SCSI hard drive with a 680000 controlling the drive electronics. Which is why I've never really understood people who focus on one chip to "define" a system, it really is about all the parts playing in harmony.
  - vidarh 10y ago
    That's funny - My 68000 based Amiga 2000 had a SCSI card in it with a Z80 on it. That machine was a real monster - I had a bridge-board in it: the A2000 had both ISA and Zorro-II (Amiga proprietary) buses, with one ISA and one Zorro-II slot in line so that you could buy a bridge-board that held an 8086 etc. on it to basically give you a "PC in a window" on your Amiga. I'd then bolted a 286 accelerator board onto it, and a 68020 accelerator board onto the Amiga-side (I think both were of the type that slotted into the CPU socket andwhere you re-seated the CPU in the accelerator in case you wanted to switch to the slower CPU for compatibility reasons) On top of that the Amiga 2000 and Amiga 500's used an 6502-compatible SOC with onboard RAM and PROM as their keyboard controllers. So that one machine had a 68000 (though not usually running), 68020, 8086 (not usually running), 80286, Z80 and a 6502-compatible. I found it quite pleasing to have one machine with representatives of four of the most common CPU families at the time in it. > Which is why I've never really understood people who focus on one chip to "define" a system, it really is about all the parts playing in harmony. It was about identity in a sense when so much was done in assembler on the main CPU, and most people are never aware of those auxiliary CPU's.
  - freehunter 10y ago
    Well, unless you can run programs on your hard disk controller, that's not the chip you use to define how fast the system is. Yes the speed of your computer is more than just the CPU, but the CPU, the RAM, and GPU are far more influential that what speed your disk's controller runs at.
- mkesper 10y ago
  The 1571 had one 6502 inside, at 2MHz (double speed of the C64 Cpu) https://en.m.wikipedia.org/wiki/Commodore_1571 https://en.m.wikipedia.org/wiki/Commodore_1571
  - david-given 10y ago
    The 8250 (the equivalent disk drive for the PET) had two 6502s inside! In today's language, one was the application processor running DOS and the other was a DSP that did the low level hardware monkeying; they were connected up to a shared data bus. Because the 6502 only does bus accesses on one phase of the clock, by inverting the clock for one processor, it was safe to connect them both up to the bus simultaneously with no loss of speed...
    - throwawayish 10y ago
      Ah right, I was thinking about the 8250 indeed. It made click when you mentioned their curious "multi-processor" arrangement.
  - vidarh 10y ago
    The 1541 had one at 1MHz. The really fun thing about these was that you could actually download code to them and run it, so if you did have code that was small enough and CPU intensive enough and required little enough IO, you could in fact use them as an accelerator of sorts (but limited by a slow serial port and 2KB(?) I think of RAM on the drive) I know of various code that downloaded code to it, but usually loaders or just to do things like blink the leds - I've never seen code that actually used the extra CPU for anything serious. I'm really curious if any exists.
    - arundelo 10y ago
      Read about Thomas Tempelmann's and Mike Pall's disk copy programs for the Commodore 64 and 1541 disk drive: http://www.pagetable.com/?p=647 http://www.pagetable.com/?p=647 http://www.pagetable.com/?p=656 http://www.pagetable.com/?p=656 From the second article: It worked by transferring the "live" GCR-encoded data from the 1541's disk head to the C64 and simultaneously doing a fast checksum. Part of the checksumming was done on the 1541, part was done on the C64. There simply weren't enough cycles left on either side! Most of the transfer happened asynchronously by adjusting for the slightly different CPU frequencies and with only a minimum number of handshakes. This meant meticulous cycle counting and use of some odd tricks.
- DashRattlesnake 10y ago
  The Apple LaserWriter printer had a faster 68000 than than contemporary Macs (12 Mhz vs 8ish MHz). https://en.wikipedia.org/wiki/LaserWriter#Hardware https://en.wikipedia.org/wiki/LaserWriter#Hardware
  - jdcarter 10y ago
    Some models of LaserWriter also had an undocumented PostScript command which would print a La Costeña order form for you to fax in. I always appreciate super-obscure Easter Eggs like that.
    - DashRattlesnake 10y ago
      That Easter egg is apparently so obscure that your comment is the only thing about it on Google: https://www.google.com/#q=%22La+Costena%22+laserwriter https://www.google.com/#q=%22La+Costena%22+laserwriter Care to share any more details?
      - hogrammer 10y ago
        I worked at Adobe during the Laserwriter days. There were easter eggs in PostScript, and we did eat at La Costena, but I know of no such Easter Egg, and I would have known about that.
      - jdcarter 10y ago
        Sorry I'm late seeing your comment, but I'll tell you what I know for posterity. I heard the story third-hand: a prior manager of mine, Mark "The Red" Harlan (of Clarus the dogcow fame), used to be a DTS manager at Apple back in the late 80's/early 90's. He also hosted a MC'd at WWDC each year called "Stump the Experts," where the audience got to challenge a panel of Apple engineers with the most obscure questions possible. One audience member asked about this PostScript command, and one of the engineers admitted to the fax-in burrito order form. Sorry I don't remember the engineer's name or which WWDC year, but I'll ping Mark.
  - cathartes 10y ago
barrkel 10y ago
Nothing will replicate the same feeling I had when I wrote my first machine code program by poking into RAM, and discovered the world of million+ operations per second, rather than thousands from the land of BASIC. It was like a glimpse of blinding light through the narrowest of cracks.
- stevekemp 10y ago
  Those were the days, I programmed in assembly language for at least two years without an assembler. As you say poking bytes into RAM, via the lookup table in the computer manual. Writing them down on paper, and trying to leave space in the code so I didn't have to recalculate all the relative JMP-offsets if I tweaked my program over a few days.

throwawayish 10y ago

> Also amusing that the STM32 supporting CPU has far more power than the main Z80 CPU. I believe some Commodore drive already had two processors identical to the main processor of the computer -- effectively giving the drive more processing power than the actual computer :)

ChuckMcM 10y ago
One of the fun things on my Z80 CP/M machine was a 20MB Seagate SCSI hard drive with a 680000 controlling the drive electronics. Which is why I've never really understood people who focus on one chip to "define" a system, it really is about all the parts playing in harmony.
- vidarh 10y ago
  That's funny - My 68000 based Amiga 2000 had a SCSI card in it with a Z80 on it. That machine was a real monster - I had a bridge-board in it: the A2000 had both ISA and Zorro-II (Amiga proprietary) buses, with one ISA and one Zorro-II slot in line so that you could buy a bridge-board that held an 8086 etc. on it to basically give you a "PC in a window" on your Amiga. I'd then bolted a 286 accelerator board onto it, and a 68020 accelerator board onto the Amiga-side (I think both were of the type that slotted into the CPU socket andwhere you re-seated the CPU in the accelerator in case you wanted to switch to the slower CPU for compatibility reasons) On top of that the Amiga 2000 and Amiga 500's used an 6502-compatible SOC with onboard RAM and PROM as their keyboard controllers. So that one machine had a 68000 (though not usually running), 68020, 8086 (not usually running), 80286, Z80 and a 6502-compatible. I found it quite pleasing to have one machine with representatives of four of the most common CPU families at the time in it. > Which is why I've never really understood people who focus on one chip to "define" a system, it really is about all the parts playing in harmony. It was about identity in a sense when so much was done in assembler on the main CPU, and most people are never aware of those auxiliary CPU's.
- freehunter 10y ago
  Well, unless you can run programs on your hard disk controller, that's not the chip you use to define how fast the system is. Yes the speed of your computer is more than just the CPU, but the CPU, the RAM, and GPU are far more influential that what speed your disk's controller runs at.
mkesper 10y ago
The 1571 had one 6502 inside, at 2MHz (double speed of the C64 Cpu) https://en.m.wikipedia.org/wiki/Commodore_1571 https://en.m.wikipedia.org/wiki/Commodore_1571
- david-given 10y ago
  The 8250 (the equivalent disk drive for the PET) had two 6502s inside! In today's language, one was the application processor running DOS and the other was a DSP that did the low level hardware monkeying; they were connected up to a shared data bus. Because the 6502 only does bus accesses on one phase of the clock, by inverting the clock for one processor, it was safe to connect them both up to the bus simultaneously with no loss of speed...
  - throwawayish 10y ago
    Ah right, I was thinking about the 8250 indeed. It made click when you mentioned their curious "multi-processor" arrangement.
- vidarh 10y ago
  The 1541 had one at 1MHz. The really fun thing about these was that you could actually download code to them and run it, so if you did have code that was small enough and CPU intensive enough and required little enough IO, you could in fact use them as an accelerator of sorts (but limited by a slow serial port and 2KB(?) I think of RAM on the drive) I know of various code that downloaded code to it, but usually loaders or just to do things like blink the leds - I've never seen code that actually used the extra CPU for anything serious. I'm really curious if any exists.
  - arundelo 10y ago
    Read about Thomas Tempelmann's and Mike Pall's disk copy programs for the Commodore 64 and 1541 disk drive: http://www.pagetable.com/?p=647 http://www.pagetable.com/?p=647 http://www.pagetable.com/?p=656 http://www.pagetable.com/?p=656 From the second article: It worked by transferring the "live" GCR-encoded data from the 1541's disk head to the C64 and simultaneously doing a fast checksum. Part of the checksumming was done on the 1541, part was done on the C64. There simply weren't enough cycles left on either side! Most of the transfer happened asynchronously by adjusting for the slightly different CPU frequencies and with only a minimum number of handshakes. This meant meticulous cycle counting and use of some odd tricks.
DashRattlesnake 10y ago
The Apple LaserWriter printer had a faster 68000 than than contemporary Macs (12 Mhz vs 8ish MHz). https://en.wikipedia.org/wiki/LaserWriter#Hardware https://en.wikipedia.org/wiki/LaserWriter#Hardware
- jdcarter 10y ago
  Some models of LaserWriter also had an undocumented PostScript command which would print a La Costeña order form for you to fax in. I always appreciate super-obscure Easter Eggs like that.
  - DashRattlesnake 10y ago
    That Easter egg is apparently so obscure that your comment is the only thing about it on Google: https://www.google.com/#q=%22La+Costena%22+laserwriter https://www.google.com/#q=%22La+Costena%22+laserwriter Care to share any more details?
    - hogrammer 10y ago
      I worked at Adobe during the Laserwriter days. There were easter eggs in PostScript, and we did eat at La Costena, but I know of no such Easter Egg, and I would have known about that.
    - jdcarter 10y ago
      Sorry I'm late seeing your comment, but I'll tell you what I know for posterity. I heard the story third-hand: a prior manager of mine, Mark "The Red" Harlan (of Clarus the dogcow fame), used to be a DTS manager at Apple back in the late 80's/early 90's. He also hosted a MC'd at WWDC each year called "Stump the Experts," where the audience got to challenge a panel of Apple engineers with the most obscure questions possible. One audience member asked about this PostScript command, and one of the engineers admitted to the fax-in burrito order form. Sorry I don't remember the engineer's name or which WWDC year, but I'll ping Mark.
- cathartes 10y ago

barrkel 10y ago

Nothing will replicate the same feeling I had when I wrote my first machine code program by poking into RAM, and discovered the world of million+ operations per second, rather than thousands from the land of BASIC. It was like a glimpse of blinding light through the narrowest of cracks.

stevekemp 10y ago
Those were the days, I programmed in assembly language for at least two years without an assembler. As you say poking bytes into RAM, via the lookup table in the computer manual. Writing them down on paper, and trying to leave space in the code so I didn't have to recalculate all the relative JMP-offsets if I tweaked my program over a few days.