Retro computer replicas (Altairduino, etc.)

[Dave Britten]

I received (and built) my Altairduino kit over the weekend, and it's a great recreation. It runs a cycle-accurate simulation on an Arudino Due, at about the same speed as an original Altair 8800. Plus there's enough headroom on the ARM to emulate floppy disks, hard disks, and different serial devices, plus the Music System for some nice low-fi audio. Various boot ROMs and BASIC examples are built in to the firmware, so you can get up and running quickly without needing to manually toggle in first-stage bootloaders and feed in paper tape for 5+ minutes (though you can still do that, even over RS-232 if you've got an old tape reader).

It's pretty surreal front-panel booting an "Altair" into CP/M and connecting a modern laptop as the terminal via USB or bluetooth and playing a game of Ladder. I think I need to track down an old serial video terminal.

The Due seems perfectly-sized for simulating the 8800, and doesn't feel like you're swatting a fly with artillery shells. It's not a board you're going to be installing a desktop-caliber Linux distribution on, that's for sure. You can also install the simulator on a Mega, but it doesn't support floppy/hard disk emulation, and runs at about 25% the speed of the original.

Anybody else built one of these, or any other cool replica computer kits? I'd love to pick up other interesting ones in the sub-$200 range. There's a Raspberry-Pi-based PDP8/I kit that looks like about the same level of difficulty.

[Zaphod]

Nice , looks like there’s a PDP11/70 in the pipeline this year too
I remember it being my Uni computer back in 1981 for a while.

http://obsolescence.wixsite.com/obsolescence/pidp-11

[toml_12953]

(04-17-2018 02:31 PM)Dave Britten Wrote:  I received (and built) my Altairduino kit over the weekend, and it's a great recreation. It runs a cycle-accurate simulation on an Arudino Due, at about the same speed as an original Altair 8800. Plus there's enough headroom on the ARM to emulate floppy disks, hard disks, and different serial devices, plus the Music System for some nice low-fi audio. Various boot ROMs and BASIC examples are built in to the firmware, so you can get up and running quickly without needing to manually toggle in first-stage bootloaders and feed in paper tape for 5+ minutes (though you can still do that, even over RS-232 if you've got an old tape reader).

It's pretty surreal front-panel booting an "Altair" into CP/M and connecting a modern laptop as the terminal via USB or bluetooth and playing a game of Ladder. I think I need to track down an old serial video terminal.

The Due seems perfectly-sized for simulating the 8800, and doesn't feel like you're swatting a fly with artillery shells. It's not a board you're going to be installing a desktop-caliber Linux distribution on, that's for sure. You can also install the simulator on a Mega, but it doesn't support floppy/hard disk emulation, and runs at about 25% the speed of the original.

Anybody else built one of these, or any other cool replica computer kits? I'd love to pick up other interesting ones in the sub-$200 range. There's a Raspberry-Pi-based PDP8/I kit that looks like about the same level of difficulty.

I've built both the PiDP-8 and the AltairDuino. When Oscar starts shipping commercial versions of the PiDP-11, I'll buy that, too. The PiDP-8 doesn't hold the same nostalgia value for me that the AltairDuino does so I don't enjoy it quite as much. I do like running Multiuser BASIC on two real serial terminals running off the $149.00 AltairDuino, though!

[ijabbott]

(04-17-2018 10:53 PM)Zaphod Wrote:  Nice , looks like there’s a PDP11/70 in the pipeline this year too
I remember it being my Uni computer back in 1981 for a while.

Mine too! Mostly for learning machine code / assembly language and various OS-related topics.

[Dave Britten]

Ooh, that PiDP-11 looks pretty sexy. If that kit comes in under the $200 mark, it'll be a no-brainer. Otherwise I'll have to agonize over the decision a bit.

I was able to get PCGET and PCPUT working last night and copied over a CP/M version of MS Multiplan, which worked like a charm when configured for a VT100. There's a large archive of commercial CP/M-80 software at this site, including a version of Forth that I might have to try out.

http://www.retroarchive.org/

What's a good full-screen text editor for video terminals in the vein of vi or pico?

[Craig Bladow]

I built a Zeta SBC Z80 computer a few years ago. It uses a mix of new and old parts so it does not need to emulate the Z80. There is a companion terminal / SD card board which I also built. It runs CP/M from Flash and has a fair amount of RAM.

[Maximilian Hohmann]

(04-18-2018 06:56 PM)Craig Bladow Wrote:  ... I built a Zeta SBC...

I still have a CPU board with a Z80 that looks very similar to the one in your link. Together with a bus board and some peripherials. Somwhere in a box in the garage. But I don't think it will ever see electrons flowing through it's circuits again. It was supposed to become my next computer after the Sinclair ZX81 some time around 1983 but development was so fast then and prices dropped so rapidly that I could afford to buy a "real" computer with color graphics and sound and floppy drives...

But that Altairduino looks tempting...

[Dave Britten]

(04-18-2018 07:21 PM)Maximilian Hohmann Wrote:  But that Altairduino looks tempting...

It's an excellent kit, and very easy to build. It's all through-hole soldering, with plenty of spacing. I'm all thumbs with woodworking, but I managed to do a decent enough job of assembling the case. You can read through the build instructions to see if it looks like it's within your comfort level.

A tip if you decide to take the plunge: the LEDs are too bright with the included 150 Ohm resistors. I've seen some others recommend going with 1K instead; I'm considering swapping them out on mine.

[hth]

(04-17-2018 10:53 PM)Zaphod Wrote:  Nice , looks like there’s a PDP11/70 in the pipeline this year too
I remember it being my Uni computer back in 1981 for a while.

http://obsolescence.wixsite.com/obsolescence/pidp-11

That seems like a seriously interesting retro computer (though my early Uni computer was a DECSYSTEM-2060 in 1987).

[Paul Berger (Canada)]

(04-17-2018 02:31 PM)Dave Britten Wrote:  Anybody else built one of these, or any other cool replica computer kits? I'd love to pick up other interesting ones in the sub-$200 range. There's a Raspberry-Pi-based PDP8/I kit that looks like about the same level of difficulty.

I receiver my kit yesterday and assembled most of it after work and finished up today. Played with it a little booted up CP/M seems to work great. I have wanted a blinking lights machine ever since I saw the operator panels on some 360 systems many years ago.

The PiDP-11 looks interesting even though I have no experience with DEC systems at all.

I also ran across a thing called "multicomp" which is basically recreating vintage micros using a FPGA with the VHDL source which could be a good VHDL learning experience.

Paul.