Re: has anybody tried to replace a vic or vic II chip with a board containing a propeller ?

From: Jim Brain <>
Date: Mon, 27 Feb 2012 18:47:07 -0600
Message-ID: <>
On 2/27/2012 5:42 PM, Ingo Korb wrote:
> The 9500XL series CPLDs are 3.3V devices, but their inputs are 
> 5V-tolerant. The EasyFlash 3 uses a 95144XL with no additional voltage 
> translators, the Chameleon actually uses a 9572XL (I think - it's from 
> that series, but the exact device may differ) mostly as voltage 
> translator for its non-5V-tolerant FPGA. 
For inputs, that is fine.  And, for outputs where the "input" is the 
actual CBM machine, that's also fine (or you can handle issues in a 
case-by-case basis.

But, the topic was single purpose replacements for CBM ICs.  For some of 
them (6502, 6510,6522,6551,6526, etc.) you don't know what's on the 
other end (user port peripheral with a need for nearly rail to rail 
voltage swings, etc.)  People will expect a cart/peripheral that worked 
on their original C64 to work with the replacement IC, so I think output 
translators will be needed.
>> Another option that I have not looked at is a small fab run. If someone
>> had a synthesizable CIA, 6502, or VIC-II netlist, I'd be willing to
>> explore a small CMOS run.
> The netlist that was reverse-engineered by the visual6502 project has
> been successfully synthesized into an FPGA, see
Yep, saw the post, but as you note below, it's far from valuable for a 
> I think you're off by an order of magnitude or two. MOSIS has an 
> online automated quote generator - 30 chips (minimum) in the ON Semi 
> I2T30 process (0.7um CMOS, the largest in the list; no idea if it 
> would be suitable) with 1mm^2 die size (random guess): 158160 USD 
> (including overnight shipping.
Well, I initially put "100s of thousands", but replaced with the more 
vague "many" because I just did not know.  I think, though, 158K puts it 
far beyond the reach of mere enthusiasts.


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Received on 2012-02-28 01:00:05

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