I recently got the Amazon Christmas toy book in the mail, and it is definitely the modern version of the Sears Christmas Wish Book for last century’s youth. Or at least the majority of last century’s youth. For the true hacker, we had a different set of wishes. Recently, I found something I’ve clung to for over 50 years: the 1975 “The Age of Altair” catalog from MITS. Now that was a wish book!
The poor thing has been dragged around for decades and, I’m sad to say, it looks it. It isn’t totally trash, but I decided I should scan it. Then I realized that Bitsavers has already done it for me and with a much nicer copy, too. The images in this post are from their scan instead.
About the Altair
The magazine that started it all (World Radio History).
If your first computer ran Windows, you might not get the significance of the Altair. Back in 1974, the idea of having your own computer was practically ludicrous. Sure, Radio Electronics had published plans for the Mark 8 in July of that year. But it used an anemic 8008 CPU, and it wasn’t easy to get all the parts you’d need to build one. Other limited computers, like the Kenbak-1 or the occasional surplus minicomputer, ended up in personal hands. But you couldn’t just decide you wanted a real computer, plunk down some money, and have one delivered unless you had extremely deep pockets.
To stay on magazine stands longer, old print mags would come out earlier than their cover date suggested. The January 1975 Popular Electronics arrived, actually, in December of 1974 — just in time for the holidays. It showed a computer you could buy as a kit or assembled: the Altair 8800. Many of us were mesmerized by the idea of owning an actual useful computer.
Reality Check
Of course, the problem is, it wasn’t actually a useful computer. All by itself, it was a bunch of switches and LEDs with a CPU. You’d need memory, and even a little was super expensive. But it was still cheaper than anything else. Want a terminal and enough memory to run BASIC? That’s going to be even more.
In those days, magazines had “bingo cards.” Each ad had a number, and if you wanted more information, you circled that number on the card and mailed it to the magazine. A while later, you’d be rewarded with mail from the company in question. I have no idea how many of the “Age of Altair” catalogs were sent, but I know I got one.
The machine on the cover didn’t look much like the machine in the magazine. The story is that the original machine was sent to the magazine for photography and was lost in the return shipping. But either way, it looked like a small minicomputer of the era.
Micro
The CPU board used what would later be called the S-100 bus.
The catalog notes a cycle time of two microseconds, or about 500 kHz. That’s a little misleading. The CPU actually ran at 2 MHz, but each instruction took multiple clock periods, and some instructions required several machine cycles. Even a simple NOP took two microseconds, while more complex instructions could take considerably longer. It wasn’t a speed demon.
One nice thing about the Altair is that it had a card cage, and you could plug in whatever you wanted with what would later be called the S-100 bus. Of course, to save money, you might not get all the card guides and connectors.
If you had deep pockets, you could get fast static memory. This would cost more and provide less memory, but the chips stored bits in flip-flops, and it was fast. Or you could opt for more dynamic memory, which stored data in tiny capacitors on its memory chips. The downside is that the memory had to periodically refresh itself, stealing cycles away from the already slow CPU.
Down with Switches
The Comter 256 showed a whole 32 characters at a time!
Naturally, you didn’t want to flip switches all the time. MITS offered the Comter 256 terminal. It had 256 bytes of its own storage and a whopping 32-character display. It even had holes to stick your phone in, if you wanted to talk to a remote computer.
This was, of course, not very practical. Your best bet was a TeleType. The TeleType Model 33 had a printer and a keyboard. The ASR variant had a paper tape reader and punch, too. Mass storage and a printer that operated at 10 characters per second. No screen, though. Everything you did was on paper. And it was pricey, too.
Software
The catalog offered a 4K and 8K BASIC along with “Extended” BASIC, which needed 12K but got you double precision math, PRINT USING, and disk I/O. There was also a single page of 8080 instructions in binary. I remember fixating on that page, trying to understand how you’d program this machine. There was a lot of missing detail.
Pricing
For as cheap as these were compared to the alternatives, they were still out of reach for many people, especially a kid. The computer itself was just a bit over $600 unless you wanted to build it yourself. Then you could save just under $200.
You couldn’t do anything without memory, though. A board that could hold 1 kB of static RAM (but only came with 256 bytes) was $134 assembled, plus $61 for every 256 bytes after that. If you wanted the board fully loaded, they discounted that to $209. The slower 4 kB dynamic RAM board was a cool $338. If you didn’t have paper tape, you probably wanted the interface to load and save programs from cassette. That was another $174.
Wanted something with a keyboard? The Comter terminal was $885, but for $35 more, you could get one that would also work with your cassette recorder to save and load things. Or opt for the TeleType for $1,500. You might be tempted by the 88-VLCT (the “low cost terminal”) at only $169. But if you saw it, it only had seven numeric keys (for octal) and two other buttons.
That’s not all. Those terminals had to plug into something. That board would run you around $140, depending on which variant you wanted. Even something like a real-time clock was an extra purchase.
The base computer price had four available slots, one of which held the CPU. So if you had a CPU, two memory cards, and a serial I/O card, you were full unless you bought more slots. To make it easier, you could buy a bundle. The cheapest was just shy of $3,000.
Perspective
Why are the addresses backward? Part of the PEMON monitor from the November 1975 Popular Electronics.
I know. It is easy enough to spend $3,000 on a state-of-the-art computer today and, at the time, this was pretty state-of-the-art. But in today’s dollars, that’s about $19,000. A new car was about $5,000, and $3,000 would get you a very nice used car. An average home ran about $42,000, and $3,000 would be a hefty part of a down payment. The median income in 1975? Under $14,000.
Still, these were the first real computers you could at least imagine buying. It wouldn’t be long before the prices of even better machines dropped considerably.
I wasn’t the only one who wanted one of these machines. I conspired with friends to pool money to get one, but we never managed it. I pored over machine code listings in later magazines and the instruction reference in the catalog, trying to puzzle it out. I finally did. In those days, you couldn’t just download the manuals or watch a video about it.
Then again, the value of an original working Altair 8800 today makes it, again, out of reach for most of us. There are always faithful recreations. Or even less-than-faithful ones. I have plenty of these recreations and simulations now, but I still have kept the catalog I pored over so many years ago.