Because I want to play with original chips. Many of them are in DIP sockets and are 5V. Not to mention linear and analog functions! No matter what, there's always wires or traces between packages.

When I want to do FPGA, I start with an IceStick or BlackIce board (Lattice ICE40 FPGA). But then it comes down to interfacing it to some other chip. So if I make a little PCB that needs more than 16 I/O pins at the edge, I've got myself into extra ribbon cable to jumper to more I/Os..

I even made one wire-wrap board with 4 socketed 74LVC245 level shifters that the BlackIce board would plug into. From there, I could do what I wanted.

I agree that damaging your wires is a serious risk. I guess I'm lucky that this never derailed me. I follow the color rule: blue on the bottom layer, yellow on the second. No daisy chains! Rather than unwrapping to get to a hidden blue wire, I can just cut it.

Also I should mention that I'm not doing anything above 25 MHz.

FWIW when wire wrapping you can get handy little hollow tools. You feed the wire in to a hole in the tool, drop the tool over the pin and just spin the tool to wrap the wire round the pin. It's all very neat and tidy and requires pretty minimal hand-eye-coordination to get it looking nice.

I bought a tiny little one of the tools a while ago when doing some raspberry pi prototyping. Makes it easy to attach a wire to the GPIO header if it's not a dupont lead/wire

The marketing managed to miss most of the time, too. (Mostly because of exec-level misguidance, though.)

In retrospect, it seems almost nuts that appliances from the past came with not only a block diagram, but a schematic. Especially now that everything is not only too complex to be documented "for your own good", and even potential repair techs, and now with DMCA protected software locks.

I still sometimes use the old Scott amplifier my parents got 50 years ago, with manual - and it has everything you need for a repair (besides a list of modern day replacement for some of these, of course). Same with the ol' Amiga 500 in a box over at their house. A lot of tinkering you could scheme on your own without going online (my quartz oscillator overclocking replacement never materialized, but hey).

Present day: I can fabricate a wire-wrap version from my PCB footprints, much faster than I can route the PCB!

With wire-wrap, you can route multiple traces between the same pins, or I like to neatly bundle a whole bus' worth.

I'm far more pleased with the results of my wire-wrap, than the quality of my SMT soldering once I get a PCB made.

I had a tutor for wire-wrap in the 1980s. But I'm self-taught in PCB routing, and I start it over at least 3 times.

When I was a kid helping my father with in-house electronics, early 1980's, this meant using specific pens and paper to layout them into boards, and then do chemical baths, drying the boards, and then hope for the best when starting to solder components on top.

Usually a mistake in any step would mean throw away the whole board and start from scratch.

I'm old-young enough to be aware of the evolution of minicomputers implemented in MSI TTL with wire-wrap (1970) to VLSI integration (1975). Examples are the LSI-11 and TMS9900.

My first home-brew micro was done in 1987 using the Radio Shack hand-tool and an OK Industries' motorized wrap gun.

Now, I add CPLD to my wire-wrap designs! Just like on an iterated PCB, you must lock the physical pins to functions.

Yes. When I was playing around with different configuration for what a machine could look like back then, you realize that the RAM cost is dominate. So you can develop as many chips as you want, that leads to high fixed cost, but the marginal cost is tiny.

While on the other hand, RAM is easely equal to all other chips on the board combined.

So you need to desperatly do everything you can to limit RAM usage. That's why Amiga was smart to do shared RAM between the CPU and the Chipset. The Archimedes did the same thing as well. And ideally you get some SRAM on there not depend on the RAM to much, ARM3 chip did that and speed improved by a huge extent.

And you really need a good operating system that could give you advanced features without completely blowing up your RAM.

That is why it is sad that nobody with sufficent capital to pump into costume chip design took on a project like that, as it needs to be somebody with the volume the economics work out.

But nobody did and instead we got there threw an iterative process where PC manufactures pumped out PC and bought the cheapest chips, while Intel and chip companies integrated the board more and more. I remember learning about Southbridge and Northbridge, and that essentially the design you end up with.

This reminds me of how expensive RAM was back then. I remember spending $180 to add 512KB to my Amiga 500 in 1988 or so. $180 was a lot of money back then.

Ram was relatively cheap between 1985 and 1987 hovering around $100-150 using 256Kbit chips. Then 1987 anti dumping laws lined up with fabs upgrading to lower yielding new 1Mbit chips and things got crazy. In 1988 256K chips went from $3.5 to $7 in less than a month. Some companies coped better than others - Atari was the first to offer computer shipping with 1MB below $1000. Tramiels little secret was smuggling ram from Japan and skirting anti dumping restrictions :)

https://forums.atariage.com/topic/207245-secret-atari-dram-r... https://web.archive.org/web/20180817061246/https://www.atari... TLDR up to $6Mil a month of smuggled ram from Japan by Atari to make money on a side :)

https://web.archive.org/web/20171220171525/https://www.atari...

"Source [an informant to the FBI who is apparently an Atari employee] remembers the first DRAM shipment arriving in 1988 was sold to Sun Micro Systems in Milpitas, CA. Source was told to deliver this shipment by [redacted]. [redacted] told Source to leave all [redacted] including his [redacted] and to take [redacted] which had an Atari logo on them. When Source delivered the Integrated Circuits, [redacted] cashier's check from Sun Microsystems to deliver to Atari, and the payee's name was left blank."

> I wonder how much faster the ARM2 would have been compared to the 68k in a first-generation Amiga.

Considerably faster. I looked at both (and the ST) and bought an Archimedes.

ARM chips benchmarked from the ARM2 up to the RasPi 3B+:

https://stardot.org.uk/forums/viewtopic.php?t=20379

68000 benchmarks around that time:

http://www.faqs.org/faqs/motorola/68k-chips-faq/

ARM2:

Dhrystone/sec 5463

68000 @ 8MHz:

Dhrystones

68000 2100

MIPS

https://en.wikichip.org/wiki/acorn/microarchitectures/arm2

https://en.wikipedia.org/wiki/Instructions_per_second

ARM2: from 6 to 10 million instructions per second, depending on instruction mix

68000: 1.4 MIPS typical.

(For comparison: Intel 8086 at the same speed, something like 300 Whetstones, 0.5 MIPS. So either of them stomped all over a comparable x86 machine from that time.)

So, very roughly, ARM2 was between 2-3x faster in typical use.

Note:

. Neither CPU could do FP in hardware.

. Neither had cache memory.

. The Amiga had a lot of complex hardware acceleration for graphics; the original ARM2 machines from Acorn (Archimedes A2305, A310, A400) had essentially none.

So, Amiga games could do things that on the Arc required raw CPU, typically done careful hand-coded assembler.

Well - I used Archimedes computers with ARM2 and owned an Amiga 500+ and honestly, I couldn't tell you the Arcie was faster. It certainly didn't have the custom chips, so it is probably not a fair comparison.

I mean NeXT machine was much more expensive then what you could have done. And need far more RAM. And of course it also used mostly commodity chips. As far as I know, but I haven't looked, they don't have fully integrated IO chips. Those were just conventional 68k workstations. Did NeXT design a single chip themselves?

> Also note that one of the original ideas for the Amiga, was to get into the UNIX workstation market

Could you source that for me? It might be true. I heard from interviews with Jay Minor that they were developing a game console, and then when the 1982 crash happened, he convinced them to pivot to a home computer. And specifically he wanted it to run games like flight simulation.

Commodore explicitly cancled its own Amiga workstation, the Z8000 based Commodore 900 Unix workstation.

When Amiga lauched they lauched with games and with pixel editors. It was endorsed by EA.

Doesn't sound like 'unix workstation' to me. It was later in the 1980s where they started to want to get into that market.

PS: BeBox much later, by then the PC ecosystem had already done most of that stuff.

Thank you, damn my dyslexia. My hands type by themselves and my brain has no idea what's going on.

Thank you!

Yeah that was in the 90s.

I always thought PA-RISC was a great RISC and it an interesting concept.

But even in that case that wouldn't have been the CPU. Commodore never dared to do that after the 6502 (of course that team left Commodore).

That and the fact that the CPU was nearly a decade old by the time they were buying them in bulk

Still incredibly cool. My Amiga 500 was the computer I have the most fond memories from. I even had a 1200 for 4 years before I reluctantly transitioned to PC.