Path: utzoo!utgpu!watmath!att!ucbvax!pro-colony.cts.com!jamesh From: jamesh@pro-colony.cts.com (James Howell) Newsgroups: comp.sys.apple Subject: Re: Using innerdrive with a laser UDC drive (long) Message-ID: <8908090915.AA05042@trout.nosc.mil> Date: 8 Aug 89 14:21:15 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 27 Network Comment: to #8675 by microsoft!brianw@uunet.uu.net Brian, Thanks for the info. This brings up an interesting question. I have an Apple //c+. The Smartport is functionally equivelant to the GS smartport. I have a C802 installed (rus fine at 4MHZ). The problem is with two old style Disk II drives (actually Tava corp clone drives). These drives work fine with my II+ through the disk controller card, but when I hang them off the //c+ smartport, I have problems. There are absolutely NO problems reading. I get write problems about 5% of the time. Sometimes a format will trash a disk, usually the disk will get trashed when copying a bunch of files, though. Copy II Plus trashes more disks than the Apple utilities, but they both trash 5.25" disks. I have been suspecting the IWM chip, but perhaps the Disk II circuitry in the GS style (not //c style) smartport is doing the same thing as the UDC card. This would be possible since //c+ come only with C02 parts and the GS comes only with C816 parts and 6502 emulation is not normal. Perhaps I'll put the original processsor back in and do some copies to verify this. You say WDC has 10MHZ 65C802 parts available? Great, I'll need to get one. I want to swap out the oscillator for a faster one and swap out the two 8K fast SRAMs for faster chips to get up to 10MHZ. How fast do you think the SRAMs would have to be? Also, who would carry them? Jameco only has down to 100 or 80ns SRAMs of this type. The //c+ already has 100 ns parts. What would I need at 10MHZ - 45ns? 35ns? Where could I find them? - Jim (301) 882-6576 (H) (202) 634-2478 (W)