Hand Held Products 71M/M eprom carrier question

[J-F Garnier]

(06-17-2020 02:51 PM)cmurillo Wrote:  

Quote:At the time, I wanted to use CMOS parts, and so I bypassed the switching element (a transistor), as you can see on attached picture, so the EPROM was always powered on and the problem was solved.

So... I take it from this that read accesses to the EPROM are slowed down by this mechanism, making this HHP device inherently slow?

Well, not necessarily. It may be, since the HALT signal is present in the card reader, but I don't think it is used by the 1LJ4 interface chip. You can have a look at this document summarizing the known information about this chip.
It may be the problem with CMOS parts that may need more time to properly power up.

BTW, if you find a way to use a 64K EPROM in the HHP EPROM carrier, I would be very interested !

J-F