From: Robert Steinmetz (rob_at_steinmetznet.com)
Date: 2003-04-12 19:04:46
Ullrich von Bassewitz wrote: >Hi! > >I've had a first look today on how to redesign the RS232 routines when >converting the drivers to loadable modules. Two questions I'm undecided about >are: > > 1. Would it make sense to support more than one serial port? > Yes Apple //c and //gs have 2 ports. > 2. If so, would it make sense to allow different drivers for the ports? > This would be desirable for Apple IIs, as it is possible to have different serial ports in different slots. I'm not sure but internal modem cards may need a from of serial prot software and there may be a serial port card for printers. Parallel Ports cards may be similar as well. >1. has some overhead, because a port number must be passed to several >routines, 2. has even more overhead, because the different ports must be >handled in the rs232 kernel functions (outside the drivers). Mixing the two >options (say: port #1 and #2 are handled by driver #1, while port #3 is >handled by driver #2) is so complex that I would say it's not worth the >trouble. > In the Apple II world at least hardware accelerators are common. As are smart serial cards, which significantly reduce the load on the main system >My approach would be to handle just one port as it is now (the 6502 has >difficulties handling even one port with decent baud rates), but since I'm >about to do a redesign on the API level, I thought I'd better ask... > >Comments anyone? > >Regards > > > Uz > -- Rob Steinmetz ---------------------------------------------------------------------- To unsubscribe from the list send mail to majordomo_at_musoftware.de with the string "unsubscribe cc65" in the body(!) of the mail.
This archive was generated by hypermail 2.1.3 : 2003-04-12 19:07:18 CEST