Apple IIe ROM and Assembly

Neo Winston

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Dec 27, 2012, 9:10:01 AM12/27/12

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Dear friends,

As I'm learning Assembly for the 6502 an old question popped again on my mind. It's about the ROM on my Apple IIe Platinum that uses the 65C02, and the more I read about this subject, the more confused I become. I know that you guys can really help me on this one!

I've read in various cracking articles about the importance of being able to stop the game execution at any time, in order to inspect the memory contents, by pressing the reset key on an Apple II, but that's not the case with my Apple IIe Platinum.

One of the Assembly books I'm studying with is "Assembly Cookbook for Apple II/IIe", by Don Lancaster (http://www.amazon.com/Assembly-Cookbook-Apple-Ii-IIE/dp/0672223317) and he talks about the various ROM chips that could be present on an Apple II, II+ and IIe computers.

That said, my questions are:

1) Do I really need to bother about the ROM I have on IIe Platinum, or should I research more about it?

2) Would it make any difference having different ROMs for programming in Assembly, or having another ROM would just help me having fun cracking games?

3) Is the information on Lancaster's book outdated, considering that I have an Apple IIe Platinum?

4)Is this the famous F8 ROM: http://www.ebay.com/itm/Apple-II-Applesoft-ROM-341-0011-A-/140886524315?pt=US_Vintage_Computers_Mainframes&hash=item20cd7dc19b ?

5) Could the above ROM be put on my machine without harming it? If so, what difference it would make, if any at all?

6) Can this card be used on my Platinum computer: http://www.ebay.com/itm/Apple-II-Integer-Basic-ROM-Card-with-rare-Programmers-ROM-341-0016-/190773075044?pt=LH_DefaultDomain_0&hash=item2c6af61c64 . If yes, what good it would bring me? Would it help me coding? Would it help me cracking games?

7) I've just purchased on eBay an Apple II Plus. Would it be better to program/crack using this computer, or the Platinum is OK for these tasks?

8) Should I proceed with this tutorial? Is it really worth the time for the things I want to accomplish (coding/cracking): http://www.antediluviandesigns.com/rom_hack.html

I think that's all for now... a lot of questions!

Again, thank you very much for your friendship and attention!

Neo Winston

gid...@sasktel.net

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Dec 27, 2012, 11:54:45 AM12/27/12

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> I've read in various cracking articles about the importance of being able to stop the game execution at any time, in order to inspect the memory contents, by pressing the reset key on an Apple II, but that's not the case with my Apple IIe Platinum.

You need to hold down the Ctrl key then press Reset

> One of the Assembly books I'm studying with is "Assembly Cookbook for Apple II/IIe", by Don Lancaster (http://www.amazon.com/Assembly-Cookbook-Apple-Ii-IIE/dp/0672223317) and he talks about the various ROM chips that could be present on an Apple II, II+ and IIe computers.

You should have the latest applesoft ROM for your enhanced IIe. About all you can do to replace chips is change the 65C02 processor to a 65008 to give you 16 bit registers.

> 1) Do I really need to bother about the ROM I have on IIe Platinum, or should I research more about it?

A 65c02 gives extra instructions but you can still program in assembly for the II+, but be aware that you do not use the extra instructions in your program.

Some games/programs will not work on an enhanced IIe because the require the original ROM, but these games are rare and there is an article in a Nibble magazine that allows you to revert the ROM back to a II+ ROM and store it in the language card, to play some of those games.

> 2) Would it make any difference having different ROMs for programming in Assembly, or having another ROM would just help me having fun cracking games?

Your current ROM's will be compatible with 99% of all games. If it is cracking that you want to do, I recommend a IIGS for all those old games. It is extremely easy to go into the control panel and then the monitor and view all your memory, and to save your memory state.

> 3) Is the information on Lancaster's book outdated, considering that I have an Apple IIe Platinum?

Yes

> 4)Is this the famous F8 ROM: http://www.ebay.com/itm/Apple-II-Applesoft-ROM-341-0011-A-/140886524315?pt=US_Vintage_Computers_Mainframes&hash=item20cd7dc19b ?

This is the ROM that came with my IIe enhancement upgrade kit. You do not need it.

> 5) Could the above ROM be put on my machine without harming it? If so, what difference it would make, if any at all?

None. You do not need it

> 6) Can this card be used on my Platinum computer: http://www.ebay.com/itm/Apple-II-Integer-Basic-ROM-Card-with-rare-Programmers-ROM-341-0016-/190773075044?pt=LH_DefaultDomain_0&hash=item2c6af61c64 . If yes, what good it would bring me? Would it help me coding? Would it help me cracking games?

No. You do not have a slot#0 but an Auxiliary slot instead.
You can run integer basic in the language card that is built into the memory. You already have 64 kb and the extended 80 column card in the auxiliary slot adds another 64 kb, to make a 128 kb machine.

> 7) I've just purchased on eBay an Apple II Plus. Would it be better to program/crack using this computer, or the Platinum is OK for these tasks?

The Platinum is fine. But for serious cracking, I would recommend an Apple IIGS since it has a control panel that makes stopping the program and viewing the memory contents much easier.

> 8) Should I proceed with this tutorial? Is it really worth the time for the things I want to accomplish (coding/cracking): http://www.antediluviandesigns.com/rom_hack.html

It is not necessary to replace any ROMs on the actual motherboard. And you do not want to risk damaging anything through ESD.

Rob

mse...@bbnmedia.org

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Dec 27, 2012, 1:39:20 PM12/27/12

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Hi Rob,

Thank you very much for all your answers! I have a IIGS in a friend's home and think I'll give it a try!

When my Apple II+ arrives I'd like to try playing with different ROM's, as described on Page 14 of the Computist (http://cd.textfiles.com/computist/pdfs/hardcore.computist/issue06.pdf)

If possible, could you please point out a cheap EPROM burner on eBay that I could be using?

Thanks again,
Neo Winston

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Antoine Vignau

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Dec 29, 2012, 2:25:35 PM12/29/12

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Rob is right. The IIgs is the perfect machine to crack 8-bit software. But there are a couple of drawbacks:
- the opcodes of the 65C02 (in emulation mode) that are seen as valid opcodes on the IIgs but that were seen as no-op on the previouo model. They were used to let the cracker wander in the code (false opcodes, e.g. Lady Tut) but such games will not boot/work fine.
- on-disk protections do not all behave correctly on the IIgs. For instance, spiradisc protections do not boot on a IIgs with the smartport interface whereas they boot on the IIgs with a Disk II interface card.

Antoine

Neo Winston

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Jan 3, 2013, 2:16:23 PM1/3/13

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Thanks, Antoine!

I'm playing with a IIgs to see how things will work out!

Neo Winston

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Dagen Brock

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Jan 3, 2013, 5:56:38 PM1/3/13

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One note about the GS and debugging if it hasn't already been mentioned. I *HIGHLY* recommend you install GSBUG on your system. It has a nice debugger with advanced features like monitoring memory locations (as raw data or as address pointers), stepping, and so on. Once installed it automatically comes up when a BRK instruction is reached or you can jump right in any time using OA-Option-Ctrl-Esc (or something like that).

It may not be perfect for working on all older titles, but I bet it's still very helpful for many cases.

Neo Winston

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Jan 4, 2013, 10:11:58 AM1/4/13

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Hi Dagen,

Thanks for your hint and sure enough I'll be taking a look at GSBUG!

Neo Winston

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BLuRry

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Jan 14, 2013, 2:44:32 AM1/14/13

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I posted a list of things I'm trying to find homes for, check comp.sys.apple2.marketplace for my posting from a few days ago. If anything looks interesting, please reach out to me soon before I resort to eBay to clear out space.

Best of luck!
-Brendan Robert