Front Panel Retrospective: Intel 8008
It's freezing in the harbor, and I'm on one of my too-infrequent work trips... mapping my normal project-management context-switching into a form so jarringly physical that I have to take laptop breaks. This is not healthy; the ratio of those orthogonal activities should be inverted.
Still, I'm enjoying the night aboard, and the stove is cranking at a cozy Fahrenheit 451° (according to mechanical instrumentation which is urging me to "Burn One"):
The book-length to-do list would be a nice candidate for incineration. Sometimes it seems an end unto itself.
I arrived with a touch of anxiety. Monday night, as I was trundling off to bed, I took a quick peek at the boat's webcam, remembering that I had forgotten to re-enable the motion-sensor that responds to activity in the pilothouse by emailing me, texting my cell phone, and FTP'ing frame grabs to an off-ship server. It was dark, since I haven't yet installed the remote lighting control... but my blood ran cold when I saw that the camera angle had shifted significantly downward since I snagged a screen capture Saturday for an article I'm writing.
Here's what it usually looks like:
But on this night, the black grainy scene had two distinct window shapes at the very top edge, and a correlating glint revealing the angle of that railing in front of the wood stove. Yikes.
My mind raced. It's a long way over and back... and what could I accomplish at 2 AM? There was no current activity in the salon, just the steady refresh showing subtle movement in the harbor water outside... but it clearly had moved. Did someone come in and fiddle with stuff, nudging the camera on its mount? There had been recent north winds, and I tried to imagine the boat whacking the dock hard enough to overcome camera-mount friction. Nah.
I fired off a letter to the port and went to bed, but sleep was fitful... though somewhere around 4 AM, I concocted a theory that the temporary EVDO antenna suction-cupped to the window had fallen down, hitting the camera in the process.
In the welcome light of morning, things looked fine on camera. Other than the angle, there was no evidence of tampering, equipment removal, rifling, partying, nesting, or any other nefarious activity. Then I saw it! A cheesy little plastic stand, part of the antenna, lying on the nav station desk! My theory had been correct... and when I arrived today, there was the proof:
Guess I really oughta finish that sloppy installation. Sometimes incomplete information is much worse than no information.
That big cable-filled gaposis, by the way, is where an ancient Furuno video sounder used to live. That whole panel region is being replaced by the new console, and one of the key jobs on this trip is to cut and fit a template (I have always done better with a hands-on model than with a set of drawings... I've measured that space a dozen times, but it won't feel real until I can touch it).
I spoke in the last posting about the investment in boat parts that rescued at least some money from the doomed stock portfolio; compared to the latter, that pile of shiny gizmology feels like my own little dotcom boomlet, still worth something close to what I paid for it. Even more fun, it's about to get mounted on a big hinged panel, provided with numerous blinkies, and interfaced to every corner of the boat.
I have a long history of this.
A Front Panel from 35 Years Ago
Apologies in advance, for this is maudlin nerdly retrospective Writ Large. I was chasing something on flickr a while ago, and came across a familiar sight: my first homebrew computer on display at the Computer History Museum. Of course I knew it was there, but back when I made the donation digital cameras were primitive, and I never got a good photo. Laughing Squid did, however, and I'm delighted to present it here (clickable for more detail):
This is only part of the old machine, which also included a Scanbe "Rapid Rack" card cage filled with 60-socket Augat wirewrap panels, a keyboard enclosure with integrated card reader, and more... a 6-foot rack cabinet that dominated my apartment living room when I was 22.
This was in 1973-4, predating those newfangled S-100 Altairs and IMSAIs that kicked off the personal computer phenomenon, and it flickered to life after a few months of obsessive design and fabrication with only the cryptic Intel 8008 databook for reference. In some primal male response to those first blinkies, I started my beard that day.
Microprocessors were bizarre back then, and at first I considered it a brief break from the ALU-based mini I was designing (and never finished). I still shudder at the 4-phase 600 kHz clock and some of the odd things that took place during transition boundaries... like the magical fleeting appearance of the content of a register if you tried to move it to itself ("load B with B" and the like). This sort of thing enabled a number of outboard enhancements that let me overcome the 8008's intrinsic shortcomings... in particular, a hardware hack that added a data stack in outboard TTL RAM in addition to the limited 7-level return stack in main memory, allowing me to save context on a subroutine call.
The machine had 4K of 8-bit static RAM made of 2102s... I originally dedicated a wirewrap board to a mere 2K, but wanted MORE... MORE! So one night, I folded out all the chip-select leads of another 16 expensive 1024-bit DIPs, then soldered them on top of the first batch and wired the floating selects back to the address decoder. Wowzers! A whopping 4K. I was ready to compute the world.
There were 8 interrupt channels, 64 bits each of input and output, a graphics subsystem using a pair of 8-bit multiplying DACs outputting X-Y to my Tek 7504 oscilloscope from a DMA display list, and a painfully slow math co-processor made from a Taylor-Series calculator chip with kluged BCD and 7-segment interface (mostly because I was intimidated by writing floating-point routines). I remember the night it drew a lovely (sin X)/X curve... took HOURS and I had consumed half a bottle of Jack Daniels by the time it was done, but it was a thing of beauty, I tellya what.
Over its useful life, this machine also implemented Walsh-function waveform synthesis and a top-octave synthesizer for music projects, a hardware polyphonic music keyboard interface that I published in Byte, a one-shot Hollerith card reader that allowed me to boot-load with a multi-punched image instead of wearing my fingers out with deposit-next, Friden paper tape reader and punch to handle my Cybertronics mailing list, newfangled 1200-baud cassette interface hacked out of a Bell 202 modem, and right outta the gate, a hardware driver for the marvelous Model 28 Baudot teletype that I still recall with wistful fondness. (This latter circuit was my first published magazine article... in the July 25, 1974 issue of Electronics magazine.)
I still have the original file of 35-year-old hand-drawn schematics made with logic templates and lots of obsessive passion... I really should scan them.
I sure do miss front panels. This one got a lot of use, and my early "screen saver" was a 555 (associated with the black knob) that allowed variable-speed single-stepping and a corresponding hypnotic blinking of the address and data bus LEDs.
I remember one debugging night when address bit 14 appeared to be always on. I popped off the wire at the driver chip (a 7404) and it was still on, so obviously there was a short to ground between there and the LED pin (the other side went to a pullup to +5). So I casually removed the wire.
The light was still on... with only one wire connected. I poured myself a drink and stared at it for a long time.
It turned out that on my hobbyist budget, I had acquired a batch of surplus LEDs that failed some parametric test along the way... and this one had been dipped crooked in the plastic. The cathode metal was thus flush with the outside of the body, and made contact with my aluminum front panel (forever being known as the infamous "field-effect LED").
Ahhh, memories. <creak> <sigh>
In a masturbatory paroxysm of gratuitous acronymism, my friends and I dubbed the machine BEHEMOTH... for "Badly Engineered Heap of Electrical, Mechanical, Optical, and Thermal Hardware." Fifteen years later, a much larger BEHEMOTH would roll out of the lab, this one the "Big Electronic Human-Energized Machine... Only Too Heavy." (It now resides in the Computer History Museum as well; here are three recent photos from the phrenologist photo pool: overall, console, seat.)
I think should coin a matching acronym for this new nautical contraption, just to keep things confusing in the spirit of Monty Python's Aussie philosophers.
Well, enough reminiscing; I have some new projects to work on. Hopefully I'll be looking back at these in another 35 years, wondering aloud, before nodding off in my geeked-out wheelchair, how I managed to sail with only a terabyte of disk on that old boat...
Still, I'm enjoying the night aboard, and the stove is cranking at a cozy Fahrenheit 451° (according to mechanical instrumentation which is urging me to "Burn One"):
The book-length to-do list would be a nice candidate for incineration. Sometimes it seems an end unto itself.
I arrived with a touch of anxiety. Monday night, as I was trundling off to bed, I took a quick peek at the boat's webcam, remembering that I had forgotten to re-enable the motion-sensor that responds to activity in the pilothouse by emailing me, texting my cell phone, and FTP'ing frame grabs to an off-ship server. It was dark, since I haven't yet installed the remote lighting control... but my blood ran cold when I saw that the camera angle had shifted significantly downward since I snagged a screen capture Saturday for an article I'm writing.
Here's what it usually looks like:
But on this night, the black grainy scene had two distinct window shapes at the very top edge, and a correlating glint revealing the angle of that railing in front of the wood stove. Yikes.
My mind raced. It's a long way over and back... and what could I accomplish at 2 AM? There was no current activity in the salon, just the steady refresh showing subtle movement in the harbor water outside... but it clearly had moved. Did someone come in and fiddle with stuff, nudging the camera on its mount? There had been recent north winds, and I tried to imagine the boat whacking the dock hard enough to overcome camera-mount friction. Nah.
I fired off a letter to the port and went to bed, but sleep was fitful... though somewhere around 4 AM, I concocted a theory that the temporary EVDO antenna suction-cupped to the window had fallen down, hitting the camera in the process.
In the welcome light of morning, things looked fine on camera. Other than the angle, there was no evidence of tampering, equipment removal, rifling, partying, nesting, or any other nefarious activity. Then I saw it! A cheesy little plastic stand, part of the antenna, lying on the nav station desk! My theory had been correct... and when I arrived today, there was the proof:
Guess I really oughta finish that sloppy installation. Sometimes incomplete information is much worse than no information.
That big cable-filled gaposis, by the way, is where an ancient Furuno video sounder used to live. That whole panel region is being replaced by the new console, and one of the key jobs on this trip is to cut and fit a template (I have always done better with a hands-on model than with a set of drawings... I've measured that space a dozen times, but it won't feel real until I can touch it).
I spoke in the last posting about the investment in boat parts that rescued at least some money from the doomed stock portfolio; compared to the latter, that pile of shiny gizmology feels like my own little dotcom boomlet, still worth something close to what I paid for it. Even more fun, it's about to get mounted on a big hinged panel, provided with numerous blinkies, and interfaced to every corner of the boat.
I have a long history of this.
A Front Panel from 35 Years Ago
Apologies in advance, for this is maudlin nerdly retrospective Writ Large. I was chasing something on flickr a while ago, and came across a familiar sight: my first homebrew computer on display at the Computer History Museum. Of course I knew it was there, but back when I made the donation digital cameras were primitive, and I never got a good photo. Laughing Squid did, however, and I'm delighted to present it here (clickable for more detail):
This is only part of the old machine, which also included a Scanbe "Rapid Rack" card cage filled with 60-socket Augat wirewrap panels, a keyboard enclosure with integrated card reader, and more... a 6-foot rack cabinet that dominated my apartment living room when I was 22.
This was in 1973-4, predating those newfangled S-100 Altairs and IMSAIs that kicked off the personal computer phenomenon, and it flickered to life after a few months of obsessive design and fabrication with only the cryptic Intel 8008 databook for reference. In some primal male response to those first blinkies, I started my beard that day.
Microprocessors were bizarre back then, and at first I considered it a brief break from the ALU-based mini I was designing (and never finished). I still shudder at the 4-phase 600 kHz clock and some of the odd things that took place during transition boundaries... like the magical fleeting appearance of the content of a register if you tried to move it to itself ("load B with B" and the like). This sort of thing enabled a number of outboard enhancements that let me overcome the 8008's intrinsic shortcomings... in particular, a hardware hack that added a data stack in outboard TTL RAM in addition to the limited 7-level return stack in main memory, allowing me to save context on a subroutine call.
The machine had 4K of 8-bit static RAM made of 2102s... I originally dedicated a wirewrap board to a mere 2K, but wanted MORE... MORE! So one night, I folded out all the chip-select leads of another 16 expensive 1024-bit DIPs, then soldered them on top of the first batch and wired the floating selects back to the address decoder. Wowzers! A whopping 4K. I was ready to compute the world.
There were 8 interrupt channels, 64 bits each of input and output, a graphics subsystem using a pair of 8-bit multiplying DACs outputting X-Y to my Tek 7504 oscilloscope from a DMA display list, and a painfully slow math co-processor made from a Taylor-Series calculator chip with kluged BCD and 7-segment interface (mostly because I was intimidated by writing floating-point routines). I remember the night it drew a lovely (sin X)/X curve... took HOURS and I had consumed half a bottle of Jack Daniels by the time it was done, but it was a thing of beauty, I tellya what.
Over its useful life, this machine also implemented Walsh-function waveform synthesis and a top-octave synthesizer for music projects, a hardware polyphonic music keyboard interface that I published in Byte, a one-shot Hollerith card reader that allowed me to boot-load with a multi-punched image instead of wearing my fingers out with deposit-next, Friden paper tape reader and punch to handle my Cybertronics mailing list, newfangled 1200-baud cassette interface hacked out of a Bell 202 modem, and right outta the gate, a hardware driver for the marvelous Model 28 Baudot teletype that I still recall with wistful fondness. (This latter circuit was my first published magazine article... in the July 25, 1974 issue of Electronics magazine.)
I still have the original file of 35-year-old hand-drawn schematics made with logic templates and lots of obsessive passion... I really should scan them.
I sure do miss front panels. This one got a lot of use, and my early "screen saver" was a 555 (associated with the black knob) that allowed variable-speed single-stepping and a corresponding hypnotic blinking of the address and data bus LEDs.
I remember one debugging night when address bit 14 appeared to be always on. I popped off the wire at the driver chip (a 7404) and it was still on, so obviously there was a short to ground between there and the LED pin (the other side went to a pullup to +5). So I casually removed the wire.
The light was still on... with only one wire connected. I poured myself a drink and stared at it for a long time.
It turned out that on my hobbyist budget, I had acquired a batch of surplus LEDs that failed some parametric test along the way... and this one had been dipped crooked in the plastic. The cathode metal was thus flush with the outside of the body, and made contact with my aluminum front panel (forever being known as the infamous "field-effect LED").
Ahhh, memories. <creak> <sigh>
In a masturbatory paroxysm of gratuitous acronymism, my friends and I dubbed the machine BEHEMOTH... for "Badly Engineered Heap of Electrical, Mechanical, Optical, and Thermal Hardware." Fifteen years later, a much larger BEHEMOTH would roll out of the lab, this one the "Big Electronic Human-Energized Machine... Only Too Heavy." (It now resides in the Computer History Museum as well; here are three recent photos from the phrenologist photo pool: overall, console, seat.)
I think should coin a matching acronym for this new nautical contraption, just to keep things confusing in the spirit of Monty Python's Aussie philosophers.
Well, enough reminiscing; I have some new projects to work on. Hopefully I'll be looking back at these in another 35 years, wondering aloud, before nodding off in my geeked-out wheelchair, how I managed to sail with only a terabyte of disk on that old boat...
posted by Steve Roberts | 1:02 AM
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