[rescue] 3b1/7300/unixpc/s4 history [was: Wanted - 3B2]

Sandwich Maker adh at an.bradford.ma.us
Wed Jul 9 11:51:50 CDT 2008

" From: Jay York <jay_york at verizon.net>
" I think the O.S. was a SVR2 derivative, with some nice additions, like  
" shared libraries.  I think it was badged CTIX.  I actually had  
" occasion to do a next gen CTIX driver gig for Unisys around that time,  
" for a Convergent 386-based box (NOT A PC).  By that point, CTIX was  
" SVR3 based.  Poking through the header files, and kernel disassemblies  
" revealed the similarities.

the convergent house brand was ctix, but they didn't go to sVr3 until
about the time the 7300 was canned.  unixpc os 3.51m was berlekey
based but svid compliant, as was the ctix it was derived from.

i'm now recalling that in between unixpc 3.00 and 3.51m were 3.50 and
3.51a in addition to 3.51c.  i don't recall a 3.51b.  one of the diffs
of 3.00 from 2.00 was hdb uucp.  i got very familiar with uucp
configuration...  stood me in vy gd stead when sun's first ppp
leveraged uucp setup.

" I still have this machine, although it's not been powered in years.   
" Some time ago, the soldered in battery got replaced with a coin  
" holder.  I think I have the voice board that went with it.  It got a  
" ST-251/1 40MB upgrade early on.  I have tubes of DRAM still waiting to  
" be soldered in - who has the time?  Never had StarLAN, always wanted  
" to build an ISA bridge to get some networking onto the box.

mine had an st251 too until i did the dual 3.5" mod, and i soldered all
the drams in on the motherboard and a ram expansion card - i was still
a tech part time and had lots o' tools and fresh skills at work.

there was an ethernet board, -very- expensive and iirc not very
robust.  better was a starlan-ethernet bridge or pc with starlan and
ethernet cards.  our 3b2s were our starlan-ethernet bridges.

i have a voice board too - wanted to make an audix answering machine.
how cool would that have been back in the late '80s?

true story - the unixpc was the console for one of att's smaller pbxes
of the time [a something 25?], and after the unixpc was canned and
inventories dumped to att vars the pbx audix option unexpectedly
became so popular that att had to buy unixpcs back to meet demand
while they hastily developed an isa voice board for the 6386.

sidebar: i was pissed when i got my 7300 at 'special employee
discount' of $1000 only to see the same systems show up at vars for
$800.  i felt better when i leard of the pbx shemozzle.

" I seem to recall that the video chip was *very* simple - I'm almost  
" thinking straight-on bit-mapped. 

there were dedicated video drams.  i don't recall if they were visible
to the memory bus but iirc it wasn't a simple bitmap - a window could
be moved by changing a single pointer to it.  thet may only have been
on the system side, not the video side.

" The MMU was custom, and effectively just a single SRAM.

iirc it was a small bank of sram [4?], but very simple and crude.
Andrew Hay                                  the genius nature
internet rambler                            is to see what all have seen
adh at an.bradford.ma.us                       and think what none thought

More information about the rescue mailing list