You went to the record store at the mall and waited in line to buy your concert tickets.
Springsteen, Eagles, Elton, Queen, etc.
Springsteen, Eagles, Elton, Queen, etc.
You might be a child in the 70s if:
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NTP2
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How? Even then that would require a insane amount of time and skill!
dr wogz
Fly caster
?
it was like, a connector, some discretes, and 8x IC chip sockets.. Wire wrap only needs a peg-board for component mounting.. and wire wrap is pretty simple, just get the right pins! Pretty easy actually..
https://en.wikipedia.org/wiki/Wire_wrap
No, not really. Not the building part. I don't know if the good doctor designed the board, but wiring it up would take two special skills (the wrapping and some soldering) that are easily learned, and a few hours work, I'm guessing two to eight, depending on the density of the RAM chips.
EDIT: Ninjad
NTP2
Well-Known Member
I sort of expected that wire wrap was referring to magnetic core memory.
That's not wrap, it's weave. That still might not be terribly difficult for a hobby scale build (I really don't know), though 16 kB of core memory would be a pretty big board*.
Here's an example that may be in the ballpark of the size and complexity of the board under discussion, though it's missing the edge connector fingers. (Dr., am I about right?)
And here's one that is decidedly NOT in the same ballpark:
* This shows an 8 kB board:
Here's an example that may be in the ballpark of the size and complexity of the board under discussion, though it's missing the edge connector fingers. (Dr., am I about right?)
And here's one that is decidedly NOT in the same ballpark:
* This shows an 8 kB board:
NTP2
Well-Known Member
I was aware of the difference after his post with the Wikipedia article, my mistake was that I knew a lot more about the AGC than 70s computers so I assumed that magnetic core was still in use then. I was wrong apparently transistor’s were small enough by then to make RAM chips practical.
Ps I guess I should stop underestimating mores law…
dr wogz
Fly caster
My wire wrapped DRAM board (4116s) never worked reliably. Too much EMI across the long WW socket pins. My WW SRAM boards worked ok. But only 4k bytes.
Homebrew Z80B machine. 1978?
PS bought most of the parts at Radio Shack!
Homebrew Z80B machine. 1978?
PS bought most of the parts at Radio Shack!
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Sooner Boomer
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Sad. I really liked her. Thought she had a great voice and lots of talent.
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I stand (sit?) corrected!
When I looked up "NASCAR logo" on Google, it didn't quite look like that.
2102 chips were the memory of choice around mid '70s. 1k x 1 bit on each chip. So a 16k-byte board took 16x8=128 individual chips.
2114 chips came out later and they were 1k x 4 bits. Much more sensible
.They were static RAM chips so tolerated wire-wrap much better. DRAM came out early '80s I think. 4116 chips. Much more timing and signal integrity-conscious
Since we are talking memories, let's not forget the EPROMs. 2708 devices were 1k x 8 bits. Unfortunately they needed three different power supplies. UV exposure to erase. If you didn't have a special eraser you could put them in the sun for a few hours.
Sanity prevailed and the 2716 (and 27C16, and subsequent devices) were all 5V only. Thank God for small miracles.
Sooner Boomer
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When I first started having trouble with my foot, back in 2017, I was looking for a "sitting around project". I inventoried and sorted all of the electrical and electronic bits I've accumulated over the years. I've got enough bare parts to build a couple of 6502 computers and mostly-enough for an 1802. Lots of 4116 DRAM, and a bunch of Hitachi 6116 SRAM.2102 chips were the memory of choice around mid '70s. 1k x 1 bit on each chip. So a 16k-byte board took 16x8=128 individual chips.
2114 chips came out later and they were 1k x 4 bits. Much more sensible
They were static RAM chips so tolerated wire-wrap much better. DRAM came out early '80s I think. 4116 chips. Much more timing and signal integrity-conscious
Since we are talking memories, let's not forget the EPROMs. 2708 devices were 1k x 8 bits. Unfortunately they needed three different power supplies. UV exposure to erase. If you didn't have a special eraser you could put them in the sun for a few hours.
Sanity prevailed and the 2716 (and 27C16, and subsequent devices) were all 5V only. Thank God for small miracles.
Programming EPROMS - my friend Joel came up with an elegant solution to the EPROMS needing 3 voltages - 5v, 12v, and a "programming" voltage of 27(?). The 5 and 12 he had. The programming voltage he derived from the back EMF of a relay he used to switch the r/w line.
Sooner Boomer
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... you were given frozen lumps of Kool Aid on a plastic stick instead of "real" Popsicles.
goose_in_co
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Hot Wheels.
Then there was Sizzlers and Fat Track!
Then there was Sizzlers and Fat Track!
Let’s not forget the Darda Buggy!
You can still get the motors and cars.
I found a website that stocks tracks and parts. Purchased a set. I set it up and everyone played with that thing for hours.
You can still get the motors and cars.
I found a website that stocks tracks and parts. Purchased a set. I set it up and everyone played with that thing for hours.
Kids these days... J/k. I made a 1kx8 SRAM with 8x 2102s. Worked great. Too much work for so little memory.
You never suffered through 1101 and 1103 DRAMs... Neither did I, that was 8008 times, 1973. And 1702 EPROMS. Quartz window, UV lamp. Dodged a bullet there, too. 2716s forever.
Great! I'll be right over! I liked the 1802, unique design.
Sooner Boomer
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Very generous, thanks! I'd trade you but I've been giving away stuff. Including SAD1024s in original packaging, Radio Shack ha ha.
Sooner Boomer
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Yeah they are classic. Better than Echoplex. Somewhere in my rock and roll career I had a Roland with SAD4096 in it, very high quality and very long delays... To go with all of our very long hair and long guitar solos... In the days before "11". The world changed.
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That song spawned a whole generation of drummers and keyboard players.
bobby_hamill
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I laughed so hard when I found out why the Britts call the public bathroom a "LOO"
I really miss the music shows of the 1970s. Captain & Tennille are one of them. The reality TV and game shows of today are no match.
Or X-rays. Some of the chips, 2716, 2732, maybe others, were also available as write once PROMS, in cheaper plastic packages, under a different part number. As an experiment, and to confirm it was actually the same chip inside, my father and a colleague from The Labs took one to a dentist to expose under his X-ray machine. It was erased, and they could re-burn it. (May have shortened its life, though.)
More 1802 fans! Hi-dee-ho, neighbors.
dr wogz
Fly caster
And there was also Tony Orlando and Dawn, Sunny and Cher etc.. And He Haw really did have musical spots in-between the comedy
dr wogz
Fly caster
staying up late to catch these guys...
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