🚀 go-pugleaf

>In article <MS.V3.18.rs4u.80022e03.dorrance.ibm032.743.6@andrew.cmu.edu> rs4u#@ANDREW.CMU.EDU (Richard Siegel) writes:
>>
>> [ how can I write code that will use the serial ports on the mac at speeds
>>   higher than those allowed through the serial driver ?              ]
>>
>>Thanks in advance for any help.
>>
>>		-Rich
>
>
>I wrote some code for the serial ports on the mac, and I would guess that what
>you'ld have to do is either write a device driver, that would give you control 
>of the hardware registers on the SCC, or work your way into the current device
>driver, but putting the address of your own routine in one of the interupt 
>dispatch tables. I don't know what the top speed of the SCC is but if you get 
>the appropriate hardware manuals for the SCC im sure you could find out.


There is a VERY good article that describes how to directly access the
Z8530 SCC chip.  It is in MacTutor, Vol.2 No.1 Jan '86. pg. 34

The article describes the nine read-only registers, and the 16 write-only
registers and how to access them from pascal (Modula 2 actually is what the
source is given in, which makes for very readable code.)

It also gives the Address for Zilog, Inc.

Zilog, Inc.
1315 Dell Ave.
Campbell, CA 95008
Attn: Publications

Send $6 and ask for the Z8030/Z8530 SCC Serial Communications Controller
Technical Manual, part number 00-2057-02. (I hope my english-teacher never
sees that sentence :-)

The MacTutor article also gives the low-memory globals location of the SCCRd
and SCCWr pointers to the SCC chip registers. ( You will need these to be
compatable with the SE & Mac// serial configurations.)

Good luck
     - Marc Tamsky                      Sinners can repent,
                                        but stupid is forever.
ARPA: crash!marct@nosc                       - Fortune Cookie
INET: marct@crash.CTS.COM
UUCP: {akgua, hplabs!hp-sdd, sdcsvax, nosc}!crash!marct