July 2, 1991

I am making an intermediate release of GRINOS v0.4á, designated N1BEE 910702.
This release differs from N1BEE 910630 only in that the HAPN drivers are being
included on a test basis.  Therefore, the release of GRINOS-S designated N1BEE
910630 will remain current, as the HAPN drivers are not and will not be bound
into the small version.  A size increase of about 8K will be noted by users of
the large version.

Unfortunately, including the HAPN drivers pushed the compiler's DGROUP, which
is made of up of initialized and uninitialized static data, past the maximum
size limit of 64K.  In order to get GRINOS to link successfully, I enabled
the automatic far data threshold in the compiler and set it to 255 bytes.
This moved six data items out of DGROUP.  These items relate to the ttylink
screen display, the IP router, the AX.25 driver, the DRSI driver, the 8250
driver used by the ASY hardware type, and the SLIP driver.  If bugs have
been introduced in any of these functions by my compiler tweaking, which
would actually surprise me, this is most likely the cause.  For the sake of
convenience, this far data threshold will also be used in GRINOS-S beginning
with v0.5, provided that no serious problems are reported.

The HAPN driver, which supports the HAPN card, is the 03-26-91 version.  It
supports selectable IRQ, even though the HAPN card is usually hardwired to
IRQ2.  Only one HAPN card can be supported by NOS at this time.  The syntax
for the attach command is:

attach hapn <baseio> <IRQ> ax25 <label> <rxbuffersize> <mtu> <duplex> <IPaddr>

The <IPaddr> is optional and will default to the main IP address if omitted.
An example of a standard attachment would be:

attach hapn 0x310 2 ax25 ha0 2048 300 csma

(Please note that IRQ2 is not recommended in an AT-class machine with a 16-bit
bus due to the motherboard's use of it for the cascade interrupt.  Hardware
IRQ9 is remapped to IRQ2 for EGA and some VGA cards, which use it for their
vertical retrace interval signal.)

-- Mike Bilow, n1bee@n1bee.ampr.org