Saturday, February 13, 2010

September 1976 Issue of Interface Age

The famous advertisement for the Apple 1 first appeared in the September 1976 issue of Interface Age, not the October issue as is widely believed. This issue also has an article on a 6502 dis-assembler, which was written by Steve Wozniak and Allen Baum, with source code listing included. Apparently, this code was available on an Apple-1 Cassette. I don't know if this code is available on the internet (maybe Vince Briel's Replica 1 includes this utility?). I just received this magazine today, so I have not read the whole article yet...

More info on the datanetics keyboard

Wendell Sander informed me today that he believes the first Apple II keyboards may have been manufactured for Apple, by Datanetics, Inc. He sent me this early Apple II keyboard schematic scan from the 1979 Apple II Reference manual.
I also contacted Steve Wozniak yesterday, but he said that if he has any info on the Datanetics, that it is probably somewhere in storage. I also asked him about the modifications, but he did not know / doesn't remember, if the electrolytic cap was original or not.

UPDATE: from Cameron Cooper: "John, the early Apple II keyboards were definitely made by datanetics. You can see one of Mike's on this page: Apple II Keyboard
From what I gather around the keyswitch patents, it looks like Apple may have acquired either Datanetics or some of their technology."

Thanks Cameron!

Saturday, February 6, 2010

Discouraging start to the day...

Well, I don't know what the heck happened here, but my keyboard decided not to function today. It was working fine last night... I burned a new BASIC EPROM chip, plugged in the firmware card, powered up the board, and now the keyboard is not working. Some keys work: 1, A, S, D, E, H, J, K, L, Q and that's about it. Most of the other keys do not work. My keyboard has always been flaky, and restarting usually worked. But today, no deal!

UPDATE: I hooked the keyboard up to an Apple II Plus and verified that the problem is the keyboard.


Wednesday, February 3, 2010

Apple-1 BASIC Firmware Card

Another EUREKA moment... well, sort of...
I spent some time over the last few weeks building an expansion card with Apple-1 BASIC programmed on an EPROM. I am able to see the code starting at address $E000. I had initially included a 7404 inverter on the card (as in the picture) but it is not needed and the wiring has all been disconnected and the chip removed. I will post details on how I built this card soon... I am still trying to get BASIC to actually run.

After a little more research it looks like I'm going to be adding a 7410 3 input NAND gate, so that I can AND and invert VMA * clock(00) * J3 pin 11 and the output will be connected to /CE on the EPROM. When all 3 inputs are active HIGH, the output will be LOW, thus activating EPROM.

UPDATE Feb/3/2010: After looking at the schematics again, I guess I don't need to add any gates.
I have been trying to get BASIC to run using the following commands without any luck:

Start system
Clear screen, Reset
enter: E000R
output: E000: 4C@

At this point, I can't do anything except for a reset. No keyboard input is accepted.
4C is the first byte of BASIC. I should be getting the ">" prompt according to the manual.

I also tried the following:
Start system
Clear screen, Reset
enter: E000.E000R
wait until the "\" appears (as stated in the manual when loading from cassette)
output afterwards, these are the last 3 bytes I see, plus the cursor: E_\@
enter: E000R
output: E000: 4C@