I have a 1997 vintage design based on an OKI MSM82C55A-2VJS. This part was EOL in 9/2004 and last time buy 1/2005. I'm hoping to not rev. the artwork and find a drop in solution. I went to Intersil and realized the IS82C55A and CS82C55A were possible candidates (the -5 parts would have too long of a read pulse requirement). So I sampled them in...here's where it gets interestng! The RESET line is tied to a supervisory circuit (chip) that is common with my DS80C320 micro. Apparetnly the OKI resets to all ports as inputs with high impedance but there's a section in the Intersil spec. reset area that says "will hold the I/O port inputs to a logic 1 state with a maximum hold current of 400 ua". So I googled on this and this seems to have been problematic for others familiar with the OKI. I suspect these internal "bus hold devices" are my problem. So, I need some help from the 8052 gurus:

1) This product/design is near EOL (18-24 months)...ok, near is subjective. So I really want to find a drop in. Are there other high speed 82C55A parts with a reset common to the OKI? It appears the origianl designer banked on the OKI reset methodoology. I scanned the "original" Intel spec. to try to assess what the 82C55A (dare I say) should do for reset methodology and all I see is "all porst are set to the input mode".

2) I've seen postings about a CPLD fix. I assume I could find one in a PLCC 44 lead format. As I only used Mode0/Word8 and Mode0/Word12 I don't think this would be all that difficult. My '373 latch would still provide A0/A1 for decode and the wr/ rd/ signals could be used for the rest. I could customize the reset mehtodology. I think the most difficult part would be the 8052 bus side. Any comments in this regard? How's the cost?

3) Are OKI's still available at reasonable cost? Any decent brokers to recommend?

Thanks,
Rich