[Coco] GIME Question

[Mark Marlette]

Roger,

Just because the data outputs are hiZ doesn't mean the address bits  
are off the buss. They are always present.

The Pro-Tector was designed to buffer the CPU, like a good design  
would. Don't know how many times I have saved the CPU by not following  
proper cart. slot rules.

I don't keep track of all of the loading rules in my head and family  
types. Google them and I'm sure you will have enough to figure out if  
it matters or not.

I only sugguested it, marginal data, or erratic operation is a hard  
problem to track down.

Regards,

Mark



Quoting Roger Merchberger <zmerch-coco at 30below.com>:

> Rumor has it that Mark Marlette may have mentioned these words:
>
>> Remember that on a CC3, the address bus is NOT bufferred and is driven
>> directly from the CPU. Watch your load counts.
>
>> who was Quoting Mike Pepe <lamune at doki-doki.net>:
>>
>>> You don't have to desolder the entire ROM. One neat trick is to lift
>>> one of the ROM's enable pins off the the board, solder a socket on top
>>> of the ROM, and install a switch. Then you can install your modified
>>> ROM and have the ability to switch back to normal without having to
>>> open the CoCo up.
>
> Mark,
>
> [[ Not questioning your hardware knowledge - you've prolly forgetten
> more than I'll ever learn! ;-) Just asking to learn... ]]
>
> How much extra load would a "spare ROM" in High-Z (unselected) mode add
> to the address buss?
>
> Also (second but mainly unrelated question) if the ROM isn't CMOS,
> could you yank the stock ROM and solder in 2 CMOS EPROMs (say,
> 27c256's) and keep within the standard buss load?
>
> Laterz,
> Roger "Merch" Merchberger
>
> --
> Roger "Merch" Merchberger  --  SysAdmin, Iceberg Computers
>  _±±_                          zmerch at 30below.com
> (©||®)  If at first you don't succeed, nuclear warhead
>  _)(_   disarmament should *not* be your first career choice.
>
>
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