VCF East 2021: Preserving Heathkit’s 8-Bit Computers

To say the Heathkit name is well known among Hackaday readers would be something of an understatement. Their legendary kits launched an untold number of electronics hobbies, and ultimately, plenty of careers. From relatively simple radio receivers to oscilloscopes and televisions, the company offered kits for every skill level from the post-war era all the way up to the 1990s.

So it's hardly a surprise that in 1977, seeing the success of early home computers like the Altair 8800 and IMSAI 8080, Heathkit decided to join the fray with a computer kit of their own. But by that point the home computing market had started to shift from a hobbyist's pursuit to something the whole family could enjoy. Compared to the Apple II and TRS-80, both of which also launched in 1977, Heathkit's machine seemed like the product of a bygone era.

While it might not have gained the notoriety of the microcomputers it was designed to compete with, the Heathkit H8 is certainly not forgotten. Tucked away in a corner at the 2021 Vintage Computer Festival East was an impressive exhibit dedicated to the Society of Eight-Bit Heath Computerists (SEBHC) called Heathkit: Keeping the Legacy Alive. Presented by Glenn Roberts, this collection of original and modern hardware demonstrated the incredible lengths to which this group of passionate Heathkit owners have gone to not just preserve the memory of these often overlooked computers, but to continue to improve upon the kit's unique design.

No Mere Clone

While the Heathkit H8 might have been designed as a contemporary to the Altair 8800, and used the same Intel 8080 CPU, it was by no means a clone like the IMSAI 8080. In perhaps the biggest departure from common microcomputers of the day, the H8 didn't use the S-100 bus. Hastily thrown together and based on military surplus 100-pin edge connectors, the S-100 bus had a number of known issues, so Heathkit decided to design a simplified 50-pin backplane design they called the Benton Harbor Bus.

Installing the H8's backplane

The backplane was mounted on the right hand side of the H8's enclosure, and could accommodate ten angled expansion cards. The first slot was naturally taken up by the front panel hardware, with the CPU board occupying the second. In the default configuration this left a generous eight additional slots for expansion purposes, though the card in the last position needed to be of a reduced length or else it would hit the power supply.

Operationally, the H8 also differed significantly from its competitors. The front panel did away with the distinctive binary toggle switches and LEDs of the Altair, and replaced them with an octal keypad and seven-segment LED displays. This allowed users to much more rapidly enter programs and examine memory addresses, although the address notation was somewhat less intuitive. That said, the H8 actually had a 1 kB ROM that contained enough code to boot the machine into a functional state, so the user didn't need to key in a loader each time they started up like they would on earlier S-100 microcomputers.

Clearly, Heathkit wasn't just looking to copy what the competition was doing. They had some very interesting ideas about how a microcomputer should work, and made a number of improvements over the defacto machines of the day. But there's always room for improvement.

Remastering a Classic

Since the H8 came in kit form and included complete schematics, members of the SEBHC have been able to create modern replicas that roll in various tweaks and improvements. With community developed PCBs and documentation, it's possible to create a functional Heathkit H8 without having any of the original hardware.

An H8-2000, with IDE drive and ATX PSU.

Depending on which generation of PCBs you use, these are referred to as H8-2000s or H8-2020s by members of the community. Without the benefit of the original enclosure these machines can end up looking rather industrial, but the aesthetics are largely dependent on how far the person building the system wants to go. Of course, if you're fortunate enough to have an original H8 (or at least, parts of one), you can augment it with the newly developed components and expansions for the best of both worlds.

Members of the SEBHC such as Norberto Collado have developed an incredible array of expansion cards to fit the H8, such as memory upgrades, IDE controllers, networking interfaces, a USB controller that supports Mass Storage devices, and even a new CPU board that uses the Z80. A properly outfitted H8 has the potential to be a retrocomputing dream machine.

Glenn put two such H8s right at the head of the table to grab the attention of passing attendees, as even to the uninitiated, it was abundantly clear these computers were the result of some blended design. Seeing the vintage enclosures outfitted with modern ATX power supplies and newly-manufactured expansion boards, show goers couldn't help but be curious. Particular attention was paid to what Glenn calls "Big Blue", a H8-2020 outfitted with a startling blue LED display and lighted keypad, a gorgeous blend of 70s simplicity and modern style.

Copying the Competition

In an effort to catch up to newer machines from the likes of Apple and Tandy, Heathkit soon introduced a new desktop machine, the H89. It was based on the Z80, combined a 12 inch CRT display and disk drive into one unit, and was available in both kit and pre-built forms. The end result was something that looked a lot like the TRS-80 Model III, and nothing like the H8 that came before it.

Set up right next to Glenn's table, Alex Bodnar brought his beautiful H89 along as part of an exhibit he called Adventure 1.0 on the Heathkit H89. As the name implies, his machine was set up running the CP/M version of the text adventure off of the original floppies offered by the Heath Users' Group.

Unfortunately, Heathkit's days in the computer game were numbered. Not long after the release of the H89, the company was purchased by Zenith, who in turn rebranded the H89 as the Z-89 and ended sales of the kit version. The Z-89 went through a few revisions and stayed on the market until 1985, but the Heathkit name would never again grace the front panel of a computer.

For a New Generation

Despite Heathkit being exceptionally well known brand among electronic hobbyists, relatively few are familiar with their brief foray into the computer market. Several attendees came away from Heathkit: Keeping the Legacy Alive surprised that a company they knew so well had developed and marketed multiple computers that they'd never even heard about.

The Heathkit H8 might never have gotten the chance to star opposite Matthew Broderick back in the 1980s, but through the efforts of the Society of Eight-Bit Heath Computerists, this vintage computer seems well positioned to get a second chance at life. The fact is, you can build a brand-new H8 today that's more capable and more reliable than the original from 1977. So whether you're looking for a unique electronics project or want to explore the world of retrocomputing, a Heathkit might be just what you're looking for.

#cons #featured #history #retrocomputing #heathkit #intel8080 #microcomputer #vcfeast #vcfeast2021

VCF East 2021: Novasaur TTL Computer Sets the Bar

There was certainly no shortage of unique computers on display at the 2021 Vintage Computer Festival East; that's sort of the point. But even with the InfoAge Science and History Museum packed to the rafters with weird and wonderful computing devices stretching back to the very beginning of the digital age, Alastair Hewitt's Novasaur was still something of an oddity.

In fact, unless you knew what it was ahead of time, you might not even recognize it as a computer. Certainly not a contemporary one, anyway. There's nothing inside its Polycase ZN-40 enclosure that looks like a modern CPU, a bank of RAM, or a storage device. Those experienced with vintage machines would likely recognize the tight rows of Advanced Schottky TTL chips as the makings of some sort of computer that predates the 8-bit microprocessor, but its single 200 mm x 125 mm (8 in x 5 in) board seems far too small when compared to the 1970s machines that would have utilized such technology. So what is it?

Inspired by projects such as the Gigatron, Alastair describes the Novasaur as a "full-featured personal computer" built using pre-1980 components. In his design, 22 individual ICs stand in for the computer's CPU, and another 12 are responsible for a graphics subsystem that can push text and bitmapped images out over VGA at up to 416 x 240. It has 512 K RAM, 256 K ROM, and is able to emulate the Intel 8080 fast enough to run CP/M and even play some early 80s PC games.

Better Living Through Emulation

Arguably the most noteworthy feature of the Novasaur is it's ability to emulate a vintage CPU. By taking this approach, Alastair essentially ensured that the only software he'd ever technically have to write for the computer would be a hardware abstraction layer. Once that was in place, he could simply load up existing programs and operating systems that were designed to run on the emulated chip.

In comparison, other TTL computers generally need to have new applications written for them. To use the Gigatron as an example, the system's ROM provides the user with a handful of tools and games that were written specifically for the hardware. But outside of that, your best bet for getting new software on the system would be to use the Tiny BASIC interpreter and write it yourself.

Intel 8080 Credit: Konstantin Lanzet [CC BY-SA 3.0]The Novasaur's ability to run CP/M and existing Intel 8080 software makes it a far more practical machine than others we've seen in the past, and is central to the claim of it being a "full-featured personal computer" rather than just an experiment in computing minimalism. But interestingly, a look through the project log shows that the decision to go with the 8080 didn't happen until relatively late in the game. Originally, Alastair was aiming for his machine to be compatible with something in Motorola's 6800 family of chips, or perhaps some subset of the MOS 6502.

It would be almost a year later before he made a post explaining he's decision to target the relatively overlooked RCA 1802 COSMAC. A month later, at the recommendation of Gigatron's creator Marcel van Kervinck, he reevaluated the situation once more. Originally he'd been put off by the complexity of the Z80, but the Intel 8080 seemed to offer a reasonable middle-ground. As it takes his computer 137 cycles to complete one CPU instruction, Alastair says the final emulated CPU is operating at approximately 450 kHz, or around 22% as fast as the original hardware.

Living History

While the Novasaur is an incredible accomplishment itself, one also has to give credit to Alastair for the phenomenal documentation he's put together. Since the beginning of 2019, he's been documenting every step that's gone into the planning, design, and construction of his TTL computer through log updates on the Hackaday.io page.

The fact that we can look back and see exactly what promoted him to switch gears and start focusing on Intel 8080 compatibility or what it looked like the first time the graphics system lit up a real CRT display, is an invaluable resource for others who might be working on similar systems. Of course even if you're not looking to build a TTL computer of your own, it's still fascinating to see how it all came together.

There's some irony that, even though it was on display at the 2021 Vintage Computer Festival East, the Novasaur was almost certainly one of the newest pieces of hardware in the building. After all, the PCB just hit its final (for now, at least) revision over the summer. Even still, there were few other machines that felt as truly personal as this labor of love, and I'm glad that VCF not only gave me the chance to see it up-close, but to meet its exceptionally passionate creator.

#cons #hackadaycolumns #retrocomputing #emulation #gigatron #intel8080 #ttlcomputer #vcfeast #vcfeast2021

VCF East Roars Back to Life

It didn't take long to realize that the 2021 Vintage Computer Festival East -- returning to the InfoAge Science and History Museum in Wall, New Jersey after being held virtually last year -- was a massive success. In fact, the first clue came before I even got out of my car. When a volunteer came up to my window to apologetically explain that the primary parking lot was already full and I'd have to drive down the road to an overflow lot, there was no question about it; a whole lot of folks were more than ready to shake off those pandemic blues and get back to business.

They certainly picked a great event for it. While VCF East has always been a highlight of the East Coast hacker's year, it was obvious things were really turned up to the max for this much-anticipated return to an in-person festival. With respect to all those involved in previous events, things just felt more cohesive and better organized this time around.

Veteran attendees I spoke to all felt like they were witnessing the event going through an evolutionary change into something bigger and better, while first time fliers were impressed with the buzz of activity and breadth of what was on display. In short, admiration for the event and the people working behind the scenes to make it possible was unanimous.

It's simply not possible to adequately summarize a multi-day event like VCF East in a single post, so I won't try to. This article, and the ones to follow it, serve only to document some of the highlights from my own personal time wandering through the sprawling InfoAge campus. Ultimately, there's no real substitute for making the trip to Wall, NJ and experiencing this incredible event for yourself. But if that's not an option for you, hopefully the following will give you a little taste of what the Vintage Computer Federation labors so hard over every year.

Evolution of the ENIAC

One of the benefits of going to an annual event like VCF East is that you occasionally get to see people's passion projects develop over time. What might have been little more than a proof of concept when you first saw it could end up being the talk of the show two or three years down the line. Which is precisely how I felt when I came across the group of people crowded around Brian Stuart and his expanded ENIAC simulator.

When I last saw his project in 2018, it took the form of a Raspberry Pi, a couple displays, and a 3D-printed hand controller modeled after the single close-up photograph Brian was able to find of the actual control units that operators would used at the time. But that was just on the physical level. In terms of software, he had already managed to simulate the ENIAC down to the individual electrical pulses that would have traveled through the gargantuan World War II computer. Rather than simply emulating the computer's internal machinations and presenting the user with a high-level representation, his goal was always to create an open source model that demonstrates how the machine really operated.

Those goals haven't changed, but the project has now moved into a new phase. With the simulation code essentially complete, Brian is now focusing on recreating the experience of using the ENIAC itself. With a considerably reduced footprint, of course. This year, that included a 3D-printed model of the complete computer at 1/10th scale. He's also created a 1/8th scale model of four ENIAC accumulators, complete with fully functional LED displays that approximate the original's blinkenlights.

Make no mistake, Brian's project was already exceptionally impressive in 2018. But the addition of the new physical components of his display clearly resonated with the attendees at this year's VCF, as people gathered around to marvel at his meticulous recreation. The takeaway for some might be about the importance of visual aids on a crowded show floor, but I was just glad to see his phenomenal work was getting the attention it deserves.

Local on the 8s

Events like VCF are also an excellent opportunity to see hardware that previously you were only able to admire from afar. For me, that meant getting to see the WeatherSTAR 4000 that techknight lovingly brought back to life with easily some of the best reverse engineering work to ever grace the pages of Hackaday. The machine was joined by several examples of similar weather-reporting devices in a group exhibit called Smooth Jazz and Stormy Skies, and each one of them was a fascinating look at the state-of-the-art in multimedia technology for their respective eras.

One of the particularly interesting elements of this display was an Arduino-controlled FSK encoder that's able to produce the time and data signals necessary to control at least some variants of the WeatherSTAR. The device was connected to a pair of stock WeatherSTAR Jrs -- diminutive text-only terminals that would likely have been marketed towards smaller markets that wanted basic functionality without the bells and whistles of the larger units. As the device relies on some closed source back-end code, techknight says he's not sure he'll be able to release the project in full, but does plan on documenting it in the future for those who are interested in his continuing quest to bend these iconic devices to his will.

Spotting a Silicon Celebrity

At a nearby table I also came across the now legendary Cursed Mac, though to be honest, I didn't actually recognize it at first. The extensively modified Macintosh SE was stripped of its distinctive blacked out enclosure for its appearance at VCF East, and instead was clad in an admittedly gorgeous transparent case.

Some mused whether such a drastic modification strips the Cursed Mac of its identity. After all, its amateurish paint job and the wildly contrasting colors of its optical and Zip drives are part of what earned it the moniker in the first place. But in the end, this is just the beginning of another chapter in the long and winding history of Theseus' favorite computer.

Computational Diversity

As fascinating as the more targeted exhibits were, arguably the most exciting part of VCF is seeing the incredible array of computers and hardware on display each year. From one-of-a-kind devices to machines which were never meant to see the outside of a research laboratory, even the most knowledgeable and experienced retro-computer aficionado is guaranteed to see at least a few specimens that will be completely unknown to them.

This gallery shows some of the unique, rare, and downright beautiful pieces of vintage hardware that I saw during my time at VCF East, but is in no way an exhaustive record of what was on display.

Competitive Consignment

Now normally this would be the part of the post where I would show you all of the incredible things I saw for sale at VCF. But to be perfectly honest, by the time I managed to get to the greatly expanded consignment area on Saturday afternoon, things were pretty well picked clean. Granted it was something of a revolving door, with people dropping off more car loads of oddities as the day went on; but from what I was able to gather from others, Friday morning was really where you wanted to be for the best deals and selection.

I still enjoyed looking through what was left, and a few pieces even managed to find their way into the trunk of my car, but my advice for anyone looking to get their hands on some particular piece of kit is be there when the doors open up on Friday if at all possible. Or better yet, keep an eye out for the next VCF Swap Meet.

A Spring Fling

While this year's Vintage Computer Festival East was held in October, historically it happens in May, right before things start to heat up at the Jersey Shore. Obviously COVID-19 made that date unworkable for 2021, so the decision was made early on to push it out to the Fall. While the number of cases is still a bit higher in the Northeast than VCF organizers (or anyone, for that matter) had probably hoped for, the move certainly paid off. Masks were strongly encouraged, and there was quite a bit of hand sanitizer going around, but otherwise it was about as close to a pre-pandemic event as you could expect.

Assuming the worst of this thing is truly behind us now, and that the 2022 event doesn't need to have its date pushed back, that means the next VCF East is only around seven months away. That's great news for those of us who get to walk around and gawk at all the fascinating hardware on display, but it does put extra pressure on the hard working folks at the Vintage Computer Federation who make it all possible. Luckily, helping them out is as easy as spreading the word about the VCF, and of course, buying a ticket to one of their events.

We'll certainly be there when the Vintage Computer Festival East comes back around to Wall, NJ in the Spring. Will you?

#cons #currentevents #hackadaycolumns #retrocomputing #vcfeast2021 #vintagecomputerfestival #vintagecomputerfestivaleast

Vintage Computer Festival East Reboots This Weekend

We don't have to tell the average Hackaday reader that the last two years have represented a serious dry spell for the type of in-person events that our community has always taken for granted. Sure virtual hacker cons have their advantages, but there's nothing quite like meeting up face to face to talk shop with like-minded folks and checking out everyone's latest passion project.

Luckily for classic computer aficionados, especially those on the East Coast of the United States, the long wait is about to end. After being forced to go virtual last year, Vintage Computer Festival East will once again be opening their doors to the public from October 8th to the 10th at the InfoAge Science & History Center in Wall, New Jersey. Attendees will need to wear a mask to gain access to the former Camp Evans Signal Corps R&D laboratory, but that's a small price to pay considering the impressive list of exhibits, presentations, and classes being offered.

In fact, it's shaping up to be the biggest and best VCF East yet. The Friday classes cover a wide range of topics from CRT repair to implementing a basic video controller with a FPGA, and the list of speakers include early computer luminaries such as Michael Tomczyk, the Product Manager for the VIC-20, and Adventure International founder Scott Adams. A little birdie even tells us that if you bring your copy of Back into the Storm, our very own Bil Herd will be sign it for you after his talk on the history of the Commodore wraps up Saturday evening.

If you'd rather get hands-on you can always take a walk over to the Computer Deconstruction Laboratory, InfoAge's on-site hackerspace. Glitch Works will be on hand with several popular kits such as the XT-IDE, an 8-bit ISA adapter that lets you connect (relatively) modern drives to classic machines, and the R6501Q/R6511Q Single Board Computer. If you're a bit rusty with the iron and would rather start on something a bit easier, Neil Cherry, a staple of the Hackaday comment section since before we switched to color pictures, will be instructing hackers young and old in the ways of the flux during his all-day soldering classes.

Of course, no VCF trip is truly complete until you've searched for treasure in the consignment room. The space has been expanded for 2021, and considering how long folks have had to clean out their attics and garages thanks to the pandemic, we're expecting a bumper crop of interesting hardware to wade through. If the turnout for the VCF Swap Meet in April was any indication, we'd suggest bringing some extra cash with you.

As a proud sponsor of the 2021 Vintage Computer Festival East, Hackaday will naturally be bringing you a first-hand account of the overall event as well as a deeper look into some of the incredible exhibits on display in the very near future. But words and pictures on a page can only go so far. If you've grown tired of virtual events and are looking to peek your head out, we can guarantee a trip to InfoAge this weekend will be well worth the gas money for anyone within driving distance.

#cons #retrocomputing #infoage #vcf #vcfeast #vcfeast2021