On 2015-Oct-15, at 11:20 PM, Brad wrote: > Thanks for this great explanation. So would anyone doing computing back in > the early 70s have used a 5 level machine?
As others mentioned, there was some use of 5-level machines with hobbyist computers in the 70s. 5-level machines were available as surplus in the 70s and the idea was that they could be an inexpensive terminal or hard-copy printer. So in the era of the first generation of PCs - the hobbyist era, Altair, SWTP 6800, etc. - there was some degree of effort to interface to 5-level machines. In practice I believe the use was pretty limited. It faded away pretty quickly, in part because the 5-level machines have a small character set - inadequate for 70s programming languages and apps. BTW: "-level" is just the term used in the teletype world for the number of bits in the character code. Presumably it's use in the teletype world predates the term bit for binary digit, or binary association. > I saw this one on ebay (or is it two? Not sure what the deal is here) > It's probably sacked: > http://www.ebay.com/itm/Teletype-equipment-1-model-28-writer-1-reperforater- > 1-50vdc-supply-etc-/121784463105?hash=item1c5aeb6f01:g:UR8AAOSwnDZUJHWs Well, there is a model 28 there. + inside, as much as one can see in the pic, the mechanism looks pretty good. - missing a key - looks like a pretty worn keyboard shroud - horrible paint job of the case exterior. The 'reperforator' looks like it could be this: http://www.baudot.net/teletype/M28-X.htm#M28-KTR Not directly familiar with the model but it sounds like it does keyboard-to-loop and loop-to-punch-tape-with-print Seems like a pretty steep price for the condition, esp. after shipping.
