Subject: Re: Apple 2 Custom hardware Newsgroups: comp.sys.apple2.programmer References: <8ko09q$ger$1@vax.area.com> <8kql0h$rrf$1@vax.area.com> <8kt1lv$aqa$1@nnrp1.deja.com> <%Ipc5.2238$MS4.152843@typhoon.southeast.rr.com> <1edzq4y.44tpc81bhfepgN%dempson@actrix.gen.nz> X-Newsreader: NN version 6.5.6 (NOV) From: david@uow.edu.au (David Wilson) NNTP-Posting-Host: 130.130.64.1 Message-ID: <3974f070$1@news.uow.edu.au> Date: 19 Jul 2000 10:04:00 +1000 X-Trace: 19 Jul 2000 10:04:00 +1000, 130.130.64.1 Organization: University of Wollongong Lines: 43 Path: lobby!newstf02.news.aol.com!portc01.blue.aol.com!portc03.blue.aol.com!news.maxwell.syr.edu!news.mel.connect.com.au!news1.optus.net.au!optus!news.usyd.edu.au!news.newcastle.edu.au!news.uow.edu.au!david dempson@actrix.gen.nz (David Empson) writes: >**** **** <***@***.com> wrote: >> On the other hand, there are reasons why I don't want to do usb >> #5 I have no usb devices to test with it >That isn't a problem for some of us - I have an iMac, but I can see why >you wouldn't want to try unless you test it yourself. I have seen USB mice for less than A$20 and USB prices should continue to fall. In my collection I have: 1x USB mouse, 2x USB to Parallel Printer adapter, 1x USB to IDE box (I put an internal Zip drive in it as I figured that it would be least likely to be slowed down by the USB interface). >USB 1.x at its highest speed is 12 megabits per second, which is 1.5 MB >per second. No problem (though it will be if you want to use USB on an >Apple II, since the I/O bus cannot go faster than 1 MB per second on a >IIgs, and somewhat less than that on the IIe). And mice/printers etc would only use the USB slow speed of 1.5Mb/s which is only 187kB/s - well within the capabilities of the A2 I/O bus. >There may be architectural reasons. On the Mac, at least, PCI has a >well defined architecture, both in hardware and software, and USB fits >in well with this. NuBus is less well defined on the software side of >things, and ISA is a complete mess. If I were building a USB card for the A2 I would put a PIC or other similar uP on the card to handle the USB chip and all the protocols needed and have a Smartport Interface programmed into the ROM that the Apple accesses in the slot space. Smartport supports block & character devices (has anyone ever seen a character device on a Smartport?) so should be able to handle most USB devices. >> #18 I'm suspicious that the theoretical "usb drivers" would conflict with >> my a2 raid controller's drivers. Using a Smartport interface a //e could use "standard" devices while a //gs could have drivers written to handle more complex devices. Pity the Smartport and Pascal 1.1 interfaces cannot co-exist, this means a mouse would not look like a Mouse card to software that is already written. -- David Wilson School of IT & CS, Uni of Wollongong, Australia