Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!jgreco From: jgreco@csd4.milw.wisc.edu (Joe Greco) Newsgroups: comp.sys.cbm Subject: Re: 1750 topics Message-ID: <853@csd4.milw.wisc.edu> Date: 10 Feb 89 05:52:54 GMT References: <5900@cbmvax.UUCP> <794@csd4.milw.wisc.edu> <5912@cbmvax.UUCP> <806@csd4.milw.wisc.edu> <5918@cbmvax.UUCP> <830@csd4.milw.wisc.edu> <5942@cbmvax.UUCP> Sender: news@csd4.milw.wisc.edu Reply-To: jgreco@csd4.milw.wisc.edu (Joe Greco) Organization: UW-Milwaukee Home for Out-of-date 8 bit Hackers Lines: 17 In comp.sys.cbm article <5942@cbmvax.UUCP>, fred@cbmvax.UUCP (Fred Bowen) wrote: ]What I was implying was: you are using a 1750 (C128 peripheral) on a C64. I ]know many folks do this without adding the resistor at R4 and say they have ]no problems. Have you added this resistor (390 ohm)??? The problem you are ]describing sounds like you haven't. This resistor shifts the dot clock timing ]slightly to compensate for small (TTL delays) differences between the C64 and ]C128 timing at the expansion port. There is a *factory installed* R4 on the pcb. The machine in question is located in an odd spot and I can't quite make out the color codes.... Ah well. Perhaps a patch or two and I can get a little more debugging info. -- jgreco@csd4.milw.wisc.edu Joe Greco at FidoNet 1:154/200 USnail: 9905 W Montana Ave PunterNet Node 30 or 31 West Allis, WI 53227-3329 "These aren't anybody's opinions." Voice: 414/321-6184 Data: 414/321-9287 (Happy Hacker's BBS)