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Original Transwarp and Ultima V

olePigeon

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Aug 14, 2009
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Getting a new ROM will be more difficult. eBay has both 65C02 and 65C816s for sale from China. However, after asking about buying a new ROM, it appears that the type used is difficult to program because it uses UV light (2372 ROM.)

Unless someone here can make me one, I'd be glad to buy the ROM, pay for shipping, etc.
 

george

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Apr 1, 2011
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I am surprised that 65C816 from your //GS works in TW at all. At least you are supposed to encounter some incompatibilities. Maybe the 65C02 that used to be installed in your TW is not a 4 MHz version (P4) and had problems at TW speed after some time. A picture of your TW I requested several days ago would have answered to many questions, including this one...If you think your problem with the TW is identified then replace the TW CPU with 65C02P4 or faster 65C02. I can write you a 2732 EPROM. The tracked shipping from my country to the US would be $5 or so. If not tracked it costs around $3. But it takes 2-3 weeks to arrive. I don't think you need this new rom version at all since ROM upgrade probably it is not related to the hang-ups and resets.
 
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george

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Apr 1, 2011
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There are only a few pins on the 65C816 that make it incompatible with most 6502 implementations, and the Transwarp card is specifically designed to be upgraded to a 65C816. In fact, it was one of the available options from Applied Engineering, it's the "16-bit upgrade" option listed in the brochure here: http://apple2online.com/web_documents/ae_transwarp_brochure.pdf

If you read the same brochure carefully, instead of arguing with me, you would notice that the AE engineers specified the 65C802 as an upgrade option to avoid ignorant interpretations like this "There are only a few pins on the 65C816 that make it incompatible"...But in fact the 65802 is a drop-in replacement to any system that uses 65(c)02 and this is not because of any specific design of the TW itself but is because of the engineering of WDC...
 

HoJoPo

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If you read the same brochure carefully, instead of arguing with me, you would notice that the AE engineers specified the 65C802 as an upgrade option to avoid ignorant interpretations like this "There are only a few pins on the 65C816 that make it incompatible"...But in fact the 65802 is a drop-in replacement to any system that uses 65(c)02 and this is not because of any specific design of the TW itself but is because of the engineering of WDC...

Thanks for calling me ignorant... I wasn't necessarily trying to argue with you, just trying to say why it works.

There was a thread on comp.sys.apple2 about using the 65C816 on the Transwarp card successfully last year. Though AE may have intended the 65c802 as the upgrade, the 65c816 works fine... there was some discussion about pin 1 on the 65c816 being tied low, which could cause excess power use, but wouldn't damage anything. https://groups.google.com/forum/#!topic/comp.sys.apple2/pUAJsL3DEKo

The truth is, the 65C816 is very close to pin compatible with the 6502. This thread over at 6502.org covers the pinouts, and the 65c816 was designed to be very close to a drop in replacement... http://forum.6502.org/viewtopic.php?f=4&t=2883 Which is what made the 65C802 easier to implement. I'd imagine the close compatibility was to encourage manufacturers of 8-bit 6502 systems to upgrade to the 65C816, with only minor architecture changes and excellent software compatibility.

That fact that the 65C816 DOES work successfully in the Transwarp shows that either AE was very lucky in their design, or they may have engineered it to be able to support either the 65C816 or the 65C802 for 16-bit. It is possible that some of the addressing modes / other features of the '816 could cause software incompatibilities without the hardware to support it fully (which the 65C802 would obviously have been designed to avoid)... but it does work.
 

george

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Apr 1, 2011
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408
That fact that the 65C816 DOES work successfully in the Transwarp shows that either AE was very lucky in their design, or they may have engineered it to be able to support either the 65C816 or the 65C802 for 16-bit. It is possible that some of the addressing modes / other features of the '816 could cause software incompatibilities without the hardware to support it fully (which the 65C802 would obviously have been designed to avoid)... but it does work.

They can cause not only software but hardware incompatibilities. What will handle the 16M addressing space of 65816 for example?!? Anyway to allege that a a given CPU "does work successfully" by mere running a program or two on the given system is a very blind and in this case rather empirical approach...An in-depth knowledge and severe testing is required. I have read how Intel used to test their 486 and Pentium processors once upon a time...A short look at the datasheet of 65816 should be sufficient to learn that direct replacement is impossible. Such replacement is gambling and constant doubt that any fault or software bug in such system could be caused by an incompatible CPU for it...Are you comfortable with that? For a collector's computer...that runs for a few minutes a day...maybe...
 

HoJoPo

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They can cause not only software but hardware incompatibilities. What will handle the 16M addressing space of 65816 for example?!? Anyway to allege that a a given CPU "does work successfully" by mere running a program or two on the given system is a very blind and in this case rather empirical approach...An in-depth knowledge and severe testing is required. I have read how Intel used to test their 486 and Pentium processors once upon a time...A short look at the datasheet of 65816 should be sufficient to learn that direct replacement is impossible. Such replacement is gambling and constant doubt that any fault or software bug in such system could be caused by an incompatible CPU for it...Are you comfortable with that? For a collector's computer...that runs for a few minutes a day...maybe...

I've just done some more reading... turns out the 65C816 will work in the Apple //e motherboard, if you bend out pin 1 as mentioned as causing too much power drain. The 65C816 runs fine with just a 16 bit memory bus... turns out that the pins that differ between the 65C02 and 65C816 are mostly ( 7 out of 8 ) not connected on the //e. There is a problem using a 65C816 in an Apple ][ or ][ plus, as one of these pins was used for a memory buffer purpose, not used on the //e. A project over a 6502.org was built that made a small "wedge" PCB to directly replace the 6502 with the 65C816. The '816 is designed to be very compatible with the 65C02... as they were both designed by the same engineer (Bill Mensch) and same company (Western Design Center), this is not surprising.

It was mentioned in discussions on C.S.A2 that the main benefit to running a 65C816 in your //e is to be able to use Merlin 16, which runs 4 to 5 times faster with access to true 16 bit instructions instead of having to emulate them in 8-bit (which Merlin 8 does). It was also mentioned that the 65C816 add-on for the Ramworks was somewhat unique in that it did utilize the extra 24 bit addressing to directly address the Ramworks memory... I wonder if any software (other than a patched Appleworks) made use of the direct memory addressing on the Ramworks?

So, if you develop in assembly on a //e (on real hardware, not emulated), a Transwarp card with a 65C816 installed might be a good way to speed up your work. Many people have done this upgrade, and software compatibility seems to be very good, likely because the 65C816 was designed to be able to run 65C02 software without issues, for the most part. Programs (mainly copy protected) that deliberately run what were illegal instructions on the 65C02, but instead run as valid on the 65C816 will fail, but the same programs also likely failed on the Apple IIgs.

Edit: I forgot to mention that some implementations of the 65C816 do not seem to like the floating inputs on the unused pins, but those chips are somewhat rare. The 65C816 chips found in most IIgs systems seem to work fine on the 8-bit Transwarp... though killing IIgs systems for their CPUs makes little sense, you might as well have a IIgs instead of a IIe... unless you have a defective IIgs motherboard, then salvaging and re-using the CPU only makes sense. :)
 
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olePigeon

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I got the updated ROM, thanks! I did some more testing, and as some of you already said, the new ROM didn't make any difference. :/ However, using the 65C816 seems to solve most of the problems. At least it doesn't crash anymore. So I'm happy with that. Floppy drives still have an occasional read error that they don't do when working at normal speed.
 

Wayne Stewart

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I upgraded my Transwarps with 65C816s more than two decades ago when the IIe was my main computer. So far I haven't experienced any problems
 

olePigeon

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Do you have Ultima V? Does yours BrrRrZzrRrr when reading the first disk on boot up? Interestingly, it doesn't do that if I do a reset first, then boot from the disk. Only on the very first boot.
 

Wayne Stewart

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I'm not into games. I recall seeing some boxes of Ultima games but I don't recall which ones they were. Right now they're somewhere in storage.
 

mm09

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Jul 31, 2016
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The Transwarp has problems with Ultima V. Practically no acceleration at all regardless of the CPU. Steve Malechek is maybe the only person who knows the reason.
 

olePigeon

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Yeah, I've been Googling more on this. Found quite a few old usenets regarding the issue. Ultima V just doesn't work with the Transwarp. :(

It did work briefly with my ZipChip until I broke it. Sigh.
 
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