AltairClone.com

And is there a real paper-tape punch/reader with your setup? From the posting about the cool switch-box I thought there was.

Sure it's on top of the wooden filing cabinet (poor photo). It's a DSI Data Specialties NC-2400. Works well, mainly at 300 baud, but has a high speed of 2400. I can load 4k and 8k basic and have a number of basic progs eg lunar,chase etc. I've also amended Mikes program PUNMSG to use the 2nd SIO2 board, that punches actual formed letters onto tape,great fun. I really enjoy using proper paper tape. I was wondering if you have a good supplier for paper tape it takes 25mm wide I get mine currently from http://www.gnt.co.uk (great people) but currently they are experiencing supply issues! I've made a paper winder (hand winding an 8k basic tape gets old, quickly!). I do plan to make a motorised version probably with a small diameter hub to produce smaller rolls to make it easier to store. I would love a teletype but space is limited!!!

I too use GNT for 1-inch paper-tape supplies, so it's distressing to hear that they're running short. If they run out entirely, I'm happy to go shares with you on an order from the US so that we can save something on the shipping costs. One of the projects for my students is that they write an assembly language program to punch readable messages on the paper-tape. I hadn't spotted that Mike has supplied one; I won't tell them that until after they're done and then we can compare whose code is tidiest: am expecting Mike's to win! They are totally blase about laser printers but go wild over things like the Teletype and the tape-punch where they can see their code making a machine move in real time. Tape-winders do seem to come up occasionally on Ebay: I picked one up a couple of months ago and I agree that hand-winding gets boring really quickly.

Here is part of my Minimal Computing Lab at De Montfort University, Leicester, England. (If you're American and the location sounds vaguely familiar, it's where they found the body of King Richard III a couple of years ago -- not in my lab but in the parking lot just across the street.) You can see one of our three Altair Clones, our two Teletypes, and our new display of "Obligatory 1970s Computer Room Wall Art". Thanks to everyone for supplying the ASCII art files.

Gabriel Egan

Love the DC power!

About the DC power: I'm a bit embarrassed as a knowledgeable Teletype person would change the motors and gears to get these 120V@60Hz machines to work here in England where the mains power is 240V@50Hz. My fix for the ASR-33 Teletype is a mains-powered transformer rated at 40A turning 240V@50Hz into 12V DC, which DC is fed into a US-sourced pure sine inverter that turns 12V DC into 120V@60Hz. For some reason this won't work with the KSR-35 Teletype as that machine seems to need more power at start-up than this setup can provide--the inverter trips complaining of excessive load--so for the ASR-33 it's a 12V DC boat battery feeding the inverter. It's all a bit Heath Robinson (the British Rube Goldberg) but, hey, it works!

Regards

Gabriel

That looks great, but you have the wall space for a giant poster. I will post under the snoopy post my nearly 6' banner ;-)

mail@gabrielegan.com wrote:About the DC power: I'm a bit embarrassed as a knowledgeable Teletype person would change the motors and gears to get these 120V@60Hz machines to work here in England where the mains power is 240V@50Hz.

If a small electronics project is more up your alley, you could probably run the Teletype "slow" from you A/C mains with a transformer, then make a small board with a PIC or similar processor to handle baud rate conversion (e.g., 110 <> 91.67). Enough RAM is needed in the PIC to handle the speed difference for an estimated worst-case continuous printout (e.g., one of the big banners).

Mike

I wish such a project were within my abilities. That's what retirement is for--indulging oneself by learning new tricks--I think. I don't suppose a small tweak to the firmware to make 91.67 baud one of the options on the configuration menu is do-able at your end? Didn't think so . . . !

mail@gabrielegan.com wrote:I don't suppose a small tweak to the firmware to make 91.67 baud one of the options on the configuration menu is do-able at your end?

Wow, such a wonderful simple and brilliant solution! Shouldn't be a big deal at all. Let me take a look.

Mike