brianw@microsoft.UUCP (Brian WILLOUGHBY) (03/30/90)
In a previous article, nagendra@bucsf.bu.edu (nagendra mishr) writes: >Conceivably, one could probably connect a cable to the apple II on a card >and on the other side of the cable would be the slots which sit in a case >outside the computer. Well, no one seems to think that the original Apple bus is very fast, but it is fast enough that the extra cable you are talking about would render the majority of the Apple ][ peripherals useless. Electricity travels very quickly compared to us land animals, but a few inches of cable can cause serious delays. For example, the Apple ][ is rated to use 200ns RAM on the motherboard. Most of the JameCo 16K cards come with 200ns RAM, but in a few installations the RAM card will not work unless you switch to 150ns RAM. In fact, every ][ Plus that I've put a RAM card in has needed 150ns RAM because of the ribbon cable to the motherboard that it part of the language card. Just a short 6 inches of cable is enough to require speedier parts than the design calls for. Also, I had a lot of trouble with my Laser UDC trashing 3.5" disks during a write. It only happened when the computer was on for a long period of time, but once it quit I would have to wait for the machine to cool down before it would work again. Applied Engineering suggested that the chips on my motherboard may have slowed with age and wear (my machine is about 8 to 10 years old), and I replaced them with newer parts. This fixed things up by bringing the timing back into original specifications, but I don't see how the UDC would work over a cable of any significant length. P.S. Laser had no clue as to what could be wrong with my UDC - they simply claimed that the Apple ][ Plus was no longer supported... Brian Willoughby UUCP: ...!{tikal, sun, uunet, elwood}!microsoft!brianw InterNet: microsoft!brianw@uunet.UU.NET or: microsoft!brianw@Sun.COM Bitnet brianw@microsoft.UUCP