John R Pierce wrote:
> On 03/15/12 1:20 PM, Jerry McAllister wrote:
>> But, on the 7 track, it used a 6 bit character set that excluded
>> lower case, eg was only upper case alpha, decimal digits and special
>> characters. I don't remember how binary was encoded on them,
>> probably pairs of 6 bit 'bytes' since the PPs were 12 bit 'machine'.
>
> now that I think about it, the BCD I remember *was* a 6 bit code, with
> just the core 64 characters. and the CDC machines I remember were
> 30/60 bit word sizes and the PPs were 12 bit... machines like the CDC
> 6600. so the 6 bit character code fed nicely into 7 track tape (6 bits
> plus parity). yes, this was 1960s hardware, still in use in the
> early/mid 70s, IIRC, that 6600 was largely used to support a 7600.
ACK! I was on one of those 6600's in the mid-eighties, having finished my
AA and working on the BS (part time, of course), with that weird, um, I
think it was 63 chars, and one bit for somethingorother. I fondly (NOT!!!)
remember the NOS (which I have referred to ever since as the Noxious
Operating System, esp. since the term before I'd been on a PDP-11).
But even when I started programming in '80, BCD was considered very old,
and not used. Of course, I was all IBM m/f.
>
> anyways. ancient history. i'd have said 'been there, done that, got
> the t-shirt', except I wore those t-shirts out 30 years ago.
Wonder if I still have a few punch cards laying around....
mark