Apple II Monitor ported to the Apple 1

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During the Apple 1 restoration project at the History San Jose collection there was a program tape that had been made by the original Apple 1 owner Winston Gayler. He was a well known Apple II expert at the time who wrote the book "The Apple II Circuit Description" published by Sams. One of the programs on the tape was a version of the Apple II monitor complete with Mini-Assembler that he had ported to the Apple 1. This is not an evolutionary program from the 1 to the II but rather a reverse port from the Apple II version with patches to make it work. He located the port at $E500 to $EFFF which made sense for an 8K Apple 1 but prevents simultaneous of Basic. Since the Apple II monitor is well documented it was pretty easy to move the program to other locations. One of the locations I used was $F400 to $FEFF leaving the original Apple 1 monitor at $FF00 to $FFFF. This works well with the FRAM card with the VMA mod and could work with other configurations where that space is available. I set it up so that I can easily switch between the monitors. I have posted a bunch of my relocations and some documentation on my web site at

http://www.apple1notes.com/old_apple/Monitor_II_on_1.html

Other Apple 1 environments can potentially use some of these relocated files.

WSander

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Joined: Oct 9 2011
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Re: Apple II Monitor ported to the Apple 1

Wendell,

Thanks for the files. I will try them out later this week. I guess I didn't realize that unit was Winston Gayler's Apple-1. I'm currently reading Winston's book since I recently picked up a copy on eBay.

Cheers,
Corey

tranter's picture
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Joined: Feb 1 2012
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Re: Apple II Monitor ported to the Apple 1

Any chance we could get binary download files, for people who don't have a cassette interface (like most Briel Replica 1 users)?

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Joined: Oct 9 2011
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Re: Apple II Monitor ported to the Apple 1

Tranter,

First question, I thought you had one of Vince's "beta" cassette adapters for the replica-1?

When you say binary downloadable? Do you mean a text file with the program listed so you can "type" it in over a serial port? If you have a Mac, OpenEmulator has a great Apple-1 cassette interface emulator. You can load or save apple-1 audio files. You can also cut and paste a monitor listing. OpenEmulator is very good at this. I use it a lot to make "binary", as you call them, backups of my software since I don't have Wendell's VMA Apple-1 board modification and USB board done on my Mimeo setup.

If you don't have a Mac, which BTW may explain why you got your TRS-80 pocket computer able to save and load software using a modern computer for audio and I can't (I'll email you later more info on what I discovered yesterday), I can make you a text file of the Apple monitor. Just let me know which memory address you need it for.

Cheers,
Corey

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Joined: Feb 1 2012
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Re: Apple II Monitor ported to the Apple 1

I do have a cassette interface for the Replica 1 but I haven't yet been able to get it to work reliably. I hope to get back to looking at it before too long.
Yes, I was looking for a Woz monitor dump format file that I could upload over the serial port.
If I could get that, I'll give it a try on my Replica 1. A version that loads into RAM on the Replica 1 would be ideal, e.g. starting at address $7500, $6500, or $3500.

I don't suppose there is source code around for this or patches against the original Apple II monitor? If the changes are not too major I might try reverse engineering the changes against the original monitor and apply them to the source for the Apple II version to get something that could be assembled (and easily relocated).

Regards,
Jeff

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Joined: Sep 5 2009
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Re: Apple II Monitor ported to the Apple 1

I will post Hex text files in Woz Apple 1 monitor format that should work. I don't have a Replica 1 to test them. I will also post a Hex dif from the original Apple II monitor file for at least one of the versions so you can see the differences. There is very little new code, just some patches most of which I wrote. The original was a non-autostart ROM and the mini-Assembler. Give me a day or two to put this together, I'll let you know when it is on the web site.

wsander

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Re: Apple II Monitor ported to the Apple 1

I posted the files.

wsander

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Re: Apple II Monitor ported to the Apple 1

Great! I'll try it out on my Replica 1.

Thanks,
Jeff

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Re: Apple II Monitor ported to the Apple 1

I tried the code on a Replica 1 and it worked quite well. I did not try the builds at $Bxxx or $Fxxx as they require burning to EPROM, but the other builds work fine out of RAM.

The only issue I found on the Replica 1 is that the commands that require Control keys do not work, as the Replica 1 does not emulate Control keys when using a PS/2 keyboard. They will work if entered from the serial port.

This weekend I went a little further adapted the original Apple II monitor source code from the "Red Book" to build under the CA65 assembler, then applied the changed for the Apple 1. The result is code that can be assembled from source and easily relocated.

The source code can be found here: https://github.com/jefftranter/6502/tree/master/asm/Apple%5D%5BMonitor

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Re: Apple II Monitor ported to the Apple 1

Hi,
I'm just adding these files to the 'Ultimate Apple 1 Software collection' CFFA1 disk image. I'm curious why I can't get the Bxxx and Fxxx versions to run under OpenEmulator.
I'm assuming, but could be wrong, that the Fxxx version needs the FRAM hardware to function, but I would have expected the Bxxx version to run with no problems.

Phil

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Re: Apple II Monitor ported to the Apple 1

I haven't tested the Bxxx or Fxxx versions on a Replica 1 yet as they need to be burned to EPROM. I will try that soon.

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Re: Apple II Monitor ported to the Apple 1

Oops, sorry.
Yes that makes sense. Both the Bxxx and Fxxx versions is outside the 32k memory range...sorry for my stupidity.

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Re: Apple II Monitor ported to the Apple 1

I've also just confirmed that all versions work with the POM1 Apple 1 emulator.

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Re: Apple II Monitor ported to the Apple 1

May I ask how you were able to do that with the Fxxx and Bxxx versions?

Thanks

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Re: Apple II Monitor ported to the Apple 1

The POM1 emulator supports 64K of RAM so it is able to load at these addresses.

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Joined: Sep 3 2005
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Re: Apple II Monitor ported to the Apple 1

Easy!
Thanks