Am Montag, 26. August 2019, 13:53:21 CEST schrieb afachat_at_gmx.de: > Hi there, > > has anyone actually every tried to convert the VC1541 to use the fast serial > bus of the C128? > > As I see it, on the UC3 VIA here http://www.zimmers.net/anonftp/pub/cbm/ > schematics/drives/new/1541/short-251748-rev.E-left.gif there still are > > - Port A0-7 > - CB1 > - CB2 > > unconnected. These could be used to > > - CB1/2 shift out under T2 control and > - PA0-7: connected to a 74LS164 serial-to-parallel shift-in register > > The only other thing needed would probably be a 74LS14 Schmitt trigger input > driver, a 7406 output driver, and potentially replacing the PB6 drive ID > input with an SRQIN input, and of course a fly-wire to the IEC's SRQIN pin > 1. > > What do you think? you also need some extra synchronisation to eliminate the via bug with external clocking (which is basically the reason for why its not used in the 1541). i vaguely remember it being described in either one of the datasheets, or perhaps application notes. -- http://hitmen.eu http://ar.pokefinder.org http://vice-emu.sourceforge.net http://magicdisk.untergrund.net Es ist besser zu schweigen und als Idiot verdaechtigt zu werden, als zu reden und dadurch den Beweis anzutreten. <Abraham Lincoln>Received on 2020-05-29 23:00:08
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