david@bragvax.UUCP (David DiGiacomo) (11/20/84)
In article <1165@umcp-cs.UUCP> chris@umcp-cs.UUCP (Chris Torek) writes: >Sigh. You can't *get* an 8 bit data path *and* flow control in >standard 4.2BSD. If you have some wizards lying around (``Heeeerrre, >wizard! Good boy! Here's your CPU crunchon snack'') you can hack in a >``lightly browned'' mode to do this. Did they really take "litout" out of the 4.2BSD tty driver? -- David DiGiacomo, BRAG Systems Inc., San Mateo CA (415) 342-3963 (...decvax!ucbvax!hplabs!bragvax!david)
chris@umcp-cs.UUCP (Chris Torek) (11/21/84)
LITOUT is there, but it only gives you 8 bits of output. Or is that
all one needs for a LaserJet?
--
(This line accidently left nonblank.)
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (301) 454-7690
UUCP: {seismo,allegra,brl-bmd}!umcp-cs!chris
CSNet: chris@umcp-cs ARPA: chris@marylanddmmartindale@watcgl.UUCP (Dave Martindale) (11/21/84)
> In article <1165@umcp-cs.UUCP> chris@umcp-cs.UUCP (Chris Torek) writes: > >Sigh. You can't *get* an 8 bit data path *and* flow control in > >standard 4.2BSD. If you have some wizards lying around (``Heeeerrre, > >wizard! Good boy! Here's your CPU crunchon snack'') you can hack in a > >``lightly browned'' mode to do this. > > Did they really take "litout" out of the 4.2BSD tty driver? Depends on what you want. You can get a full 8-bit path on OUTPUT with flow control just by setting LITOUT. You can get a full 8-bit path with flow control on INPUT if you hack the driver a bit to support TANDEM even in RAW mode. But you cannot get an 8 bit data path in BOTH directions with flow control at all, ever. The problem is fundamental: if you receive an XON or XOFF, how do you decide if it is part of the data or a flow control instruction from the other machine? You just cannot transmit flow-control instructions along with all-256-codes-valid data on the same wire without some sort of additional encoding being done.
henry@utzoo.UUCP (Henry Spencer) (11/22/84)
> LITOUT is there, but it only gives you 8 bits of output. Or is that > all one needs for a LaserJet? That's all you need: 8-bit output with XON/XOFF flow control. Unless there is something about the LaserJet that HP's manuals haven't told us, the only things it ever sends are XON and XOFF. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry