From: Jim Brain (brain_at_jbrain.com)
Date: 2007-11-07 01:29:51
Ethan Dicks wrote: > On 11/7/07, Jim Brain <firstname.lastname@example.org> wrote: > >> My thought was the cost of finding the connectors. For a user port, you >> could rob an old modem (though I generally discourage hacking antique >> CBM items, I can make an exception for any 1660 variant). The cassette >> port is a bit harder to find, though game carts exist in the plenty. As >> well, a small PCB with just the card edge is a mere buck to produce and >> sell for those who want a nice looking setup. >> > > I don't recall either the 6-pin (cassette port, single-sided) or the > 24-pin (user port, double-sided) connectors being particularly > difficult to find. They aren't as inexpensive as, say, a DE9 or DB25, > but they are still being made, AFAIK. > > The usual places I start with are Jameco, Digikey, and Mouser. The > connectors are ordinary 0.154" spacing edge connectors. > > DigiKey has them in stock, it's just the minimums from places like DigiKey that thwart many a project. I suppose that if you were building this, you'd buy a handful of them and hit the minimums. To carry the consensus feeling forward, how would folks use the user port for networking? I know Centipede 128 used a simple 1-1 connection to hook two machines together, but I've not seen other uses. Hooking all 8 data lines across 64 machines will not work due to fanout, so you have the following options: * Use SP1/CNT1 as an input, and SP2/CNT2 as an output. Transfers are limited to CLK/32 bytes/sec or 31K theoretical. o This allows a 4 wire data connection, though one might want to add an ATN wire to denote commands on input and output. * Use 4 bits of PB for inputs, and 4 for outputs. o More bits, but CLK/8 speed max. Any other ideas? -- Jim Brain, Brain Innovations (X) email@example.com Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times! Home: http://www.jbrain.com Message was sent through the cbm-hackers mailing list
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