Recent content by shred

Correct. Backlit Portable supports a 4MB RAM expansion card via the 50 way RAM slot, but you can add a 7MB card for a total of 8MB if you use a PDS slot card. Apple advise against using the PDS slot for this (I have the developer note), but it was quite common. I maxed my backlit Portable out...

It's been a while since I used MacTCP, but I vaguely recall that the TCP/IP stack does not get loaded until an application attempts to connect via tcp. Open a telnet session from the Mac Plus to something else & it should start responding to ping requests.

I'm coming in to this discussion a bit late, but did you try removing your RAM card and modem? At one stage, I had a third party 7MB RAM expansion card in my my backlit portable (IIRC, it went in the PDS slot, because the machine was never built to take that much RAM in the RAM expansion slot)...

To answer one of the OP's questions: yes, the speakers were sold outside the US. I'm in Australia and remember having a pair with the rainbow square logo at my place of work back in the 90s. The speakers were crazy expensive in Australia, but ours were purchased in a run out special Apple had...

I may be able to explain the presence of a third party hard drive, assuming the pricing situation in the U.S. was similar to that in Australia. The original Mac Classic and Mac LC were both very expensive to buy with a factory fitted Apple hard disk. It was much cheaper to buy a floppy drive...

The hard disk conversion in a Mac Portable (I assume you intend to use CompactFlash) is fiddly, but well worth it. I found that the original Conner hard disk was very noisy, but now the only noise is the whine from the backlight inverter and the battery life is better too.

I've never seen an original Portable with the backlit display upgrade fitted. Thanks for sharing the photos.

There were external CD burners in the 90s, but burning a CD, even at 1x speed is way beyond the capabilities of an LC. The first CD burner I came across cost megadollars and burned at 1x speed. It had quite an exotic suspension system to prevent vibration affecting the operation of the burner...

O.P.: At LocalTalk speeds of 250k bits/sec, you may find that a software "bit banging" solution drops some incoming bits while the Arduino's processor is off doing other things, like talking to the Ethernet port. Take a look at the Zilog Z8530 SCC http://en.wikipedia.org/wiki/Zilog_SCC and its...

As Dennis Nedry stated: Double check the ID of the internal drive. It is surprisingly common to find internal hard drives jumpered incorrectly as ID 6. Why? For some models of Mac, in Australia (and possibly other countries?) Apple charged unrealistically high prices for a Mac fitted with a...

Under that plastic cover is the usual thin glass nipple. You can usually crush the glass through the plastic cover using a large pair of side cutters or pliers. Another option is to grab one of the CRT socket pins in a pair of pliers and twist it - as if you are pulling it out of the CRT...

I'm suspicious of the claim that R41 and R47 have never been removed from the board. There is clearly solder flux residue present at one end of both resistors - something that you never see on an Apple board as it comes from the factory. R41 in particular looks to have been hand soldered...

The Jaz drives were horribly unreliable when new - I hate to think what they're like nowadays. Make sure you back up!

I remember them being horribly expensive, but pretty reliable. Far, far superior to the Zip/Jaz/Syquest junk that used to die and lose data when you least expected it.

The 1N5817 is a schottky diode. It has a much lower forward voltage drop than the 1N4001s that you are using, although it may not matter much for the backup battery. I don't know why there would be two diodes unless something was originally connected to the junction between the two diodes. In...